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Experimental Novels and Novelists

By NASRULLAH MAMBROL on March 6, 2019 • ( 2 )

Literature is forever transforming. A new literary age is new precisely because its important writers do things differently from their predecessors. Thus, it could be said that almost all significant literature is in some sense innovative or experimental at its inception but inevitably becomes, over time, conventional. Regarding long fiction, however, the situation is a bit more complex.

It is apparent that, four centuries after Miguel de Cervantes wrote what is generally recognized the first important novel, Don Quixote de la Mancha (1605, 1615), readers have come to accept a certain type of long fiction as most conventional and to regard significant departures from this type as experimental. This most conventional variety is the novel of realism as practiced by nineteenth century giants such as Gustave Flaubert, Leo Tolstoy, Charles Dickens, and George Eliot .

The first task in surveying contemporary experiments in long fiction, therefore, is to determine what “conventional” means in reference to the novel of realism. Most nineteenth century novelists considered fiction to be an imitative form; that is, it presents in words a representation of reality. The underlying assumption of these writers and their readers was that there is a shared single reality, perceived by all—unless they are mad, ill, or hallucinatory—in a similar way. This reality is largely external and objectively verifiable. Time is orderly and moves forward. The novel that reflects this view of reality is equally orderly and accountable. The point of view is frequently, though not always, omniscient (all-knowing): The narrators understand all and tell their readers all they need to know to understand a given situation. The virtues of this variety of fiction are clarity of description and comprehensiveness of analysis.

After reading Flaubert’s Madame Bovary (1857; English translation, 1886), one can be confident that he or she knows something about Emma Bovary’s home, village, and manner of dress; knows her history, her motivations, and the way she thought; and knows what others thought of her. Not knowing would be a gap in the record; not knowing would mean, according to standards against which readers have judged “conventional” novels, a failure of the author.

Modernism and its Followers

Early in the twentieth century, a disparate group of novelists now generally referred to as modernists— James Joyce , Virginia Woolf , William Faulkner , Franz Kafka , Marcel Proust , and others—experimented with or even abandoned many of the most hallowed conventions of the novel of realism. These experiments were motivated by an altered perception of reality. Whereas the nineteenth century assumption was that reality is external, objective, and measurable, the modernists believed reality to be also internal, subjective, and dependent upon context. Reflecting these changing assumptions about reality, point of view in the modernist novel becomes more often limited, shifting, and even unreliable rather than omniscient.

This subjectivity reached its apogee in one of the great innovations of modernism, the point-of-view technique dubbed “stream of consciousness,” which plunges the reader into a chaos of thoughts arrayed on the most tenuous of organizing principles—or so it must have seemed to the early twentieth century audience accustomed to the orderly fictional worlds presented by the nineteenth century masters.

Once reality is acknowledged to be inner and subjective, all rules about structure in the novel are abandoned. The most consistent structuring principle of premodernist novelists—the orderly progression of time—was rejected by many modernists. Modern novels do not “progress” through time in the conventional sense; instead, they follow the inner, subjective, shifting logic of a character’s thoughts. Indeed, the two great innovations of modernist fiction—stream of consciousness and nonchronological structure—are inseparable in the modern novel.

Among the most famous and earliest practitioners of these techniques were Joyce (especially Ulysses , 1922, and Finnegans Wake , 1939), Woolf (especially Jacob’s Room , 1922; Mrs. Dalloway , 1925; and To the Lighthouse , 1927), and Faulkner (especially The Sound and the Fury , 1929; As I Lay Dying , 1930). Many of the experimental works of post-World War II long fiction extended these techniques, offering intensely subjective narrative voices and often extreme forms of stream of consciousness, including disruptions of orderly time sequences.

In La traición de Rita Hayworth (1968; Betrayed by Rita Hayworth , 1971), Manuel Puig employs (among other techniques) the words of several sets of characters in different rooms of a house without identifying the speakers or providing transitions to indicate a change in speaker. The effect may be experienced by the reader as a strange solipsistic cacophony, or something like a disjointed choral voice; in fact, the technique is a variation on stream of consciousness and not so very different from the tangle of interior monologues in Faulkner ’s novels.

Tim O’Brien’s novel of the Vietnam War, Going After Cacciato (1978, revised 1989), is another example of a work that makes fresh use of a modernist strategy. Here, reality at first seems more external and hence clearer than in Betrayed by Rita Hayworth . The bulk of the action concerns a rifle squad that follows a deserter, Cacciato, out of Vietnam and across Asia and Europe until he is finally surrounded in Paris, where he once again escapes. The chapters that make up this plot, however, are interspersed with generally shorter chapters recounting the experiences of the point-of-view character, Paul Berlin, at home and in Vietnam. In another set of short chapters, Berlin waits out a six-hour guard shift in an observation post by the sea. The most orderly part of the novel is the pursuit of Cacciato, which moves logically through time and place. The perceptive reader eventually realizes, however, that the pursuit of Cacciato is a fantasy conjured up by Berlin, whose “real” reality is the six hours in the observation post, where his thoughts skip randomly from the present to the past (in memories) to a fantasy world. As in the best modernist tradition, then, the structure of Going After Cacciato reflects an inner, subjective reality.

The post-World War II writer who most famously and provocatively continued the modernist agenda in long fiction was Samuel Beckett, especially in his trilogy: Molloy (1951; English translation, 1955), Malone meurt (1951; Malone Dies , 1956), and L’Innommable (1953; The Unnamable , 1958). In each successive novel, external reality recedes as the narrative voice becomes more inward-looking. In Molloy , for example, the title character searches for his mother, but he is lost from the beginning. He can find neither her (if she truly exists) nor his way back home, wherever that is—nor can he be sure even of the objective reality of recent experience. In one passage Molloy notes that he stayed in several rooms with several windows, but then he immediately conjectures that perhaps the several windows were really only one, or perhaps they were all in his head. The novel is filled with “perhapses” and “I don’t knows,” undermining the reader’s confidence in Beckett’s words.

The subjectivity and uncertainty are intensified in Malone Dies . At least in Molloy, the protagonist was out in the world, lost in a countryside that appears to be realistic, even if it is more a mindscape than a convincing geographic location. In Malone Dies , the protagonist spends most of his days immobile in what he thinks is a hospital, but beyond this nothing—certainly not space or time—is clear. As uncertain of their surroundings as Molloy and Malone are, they are fairly certain of their own reality; the unnamed protagonist of the final volume of the trilogy, The Unnamable , does not know his reality. His entire labyrinthine interior monologue is an attempt to find an identity for himself and a definition of his world, the one depending upon the other. In those attempts, however, he fails, and at no time does the reader have a confident sense of time and place in reference to the protagonist and his world.

The New Novel

With The Unnamable , long fiction may seem to have come a great distance from the modernist novel, but in fact Beckett was continuing the modernist practice of locating reality inside a limited and increasingly unreliable consciousness. Eventually, voices cried out against the entire modernist enterprise. Among the earliest and most vocal of those calling for a new fiction—for le nouveau roman, or a new novel—was a group of French avantgarde writers who became known as the New Novelists. However, as startlingly innovative as their fiction may at first appear, they often were following in the footsteps of the very modernists they rejected.

Among the New Novelists (sometimes to their dismay) were Michel Butor, Nathalie Sarraute, and Claude Simon. Even though Simon won the Nobel Prize in Literature, probably the most famous (or infamous) of the New Novelists was Alain Robbe-Grillet.

Alain Robbe-Grillet

Robbe-Grillet decried what he regarded as outmoded realism and set forth the program for a new fiction in his Pour un nouveau roman (1963; For a New Novel: Essays on Fiction , 1965). His own career might offer the best demonstration of the movement from old to new. His first published novel, Les Gommes (1953; The Erasers, 1964), while hardly Dickensian, was not radically innovative. With Le Voyeur (1955; The Voyeur , 1958), however, his work took a marked turn toward the experimental, and with La Jalousie (1957; Jealousy, 1959) and Dans le labyrinthe (1959; In the Labyrinth, 1960), the New Novel came to full flower.

The most famous technical innovation of the New Novelists was the protracted and obsessive descriptions of objects—a tomato slice or box on a table or a picture on a wall—often apparently unrelated to theme or plot. The use of this device led some critics to speak of the “objective” nature of the New Novel, as if the technique offered the reader a sort of photographic clarity. On the contrary, in the New Novel, little is clear in a conventional sense. Robbe-Grillet fills his descriptions with “perhapses” and “apparentlys” along with other qualifiers, and the objects become altered or metamorphosed over time. After Robbe-Grillet’s early novels, time is rarely of the conventional earlier-to-later variety but instead jumps and loops and returns.

One example of the transforming nature of objects occurs in The Voyeur , when a man on a boat peers obsessively at the figure-eight scar left by an iron ring flapping against a seawall. Over the course of the novel the figure-eight pattern becomes a cord in a salesman’s suitcase, two knotholes side by side on a door, a bicycle, a highway sign, two stacks of plates, and so on—in more than a dozen incarnations. Moreover, Robbe-Grillet’s objects are not always as “solid.” A painting on a wall (In the Labyrinth) or a photograph in a newspaper lying in the gutter ( La Maison de rendez-vous , 1965; English translation, 1966) may become “animated” as the narrative eye enters it, and the action will transpire in what was, a paragraph before, only ink on paper or paint on canvas.

Such techniques indeed seemed radically new, far afield of the novels of Joyce and Faulkner. However, it is generally the case with the New Novelists, especially with Robbe-Grillet, that this obsessive looking, these distortions and uncertainties and transformations imposed on what might otherwise be real surfaces, have their origins in a narrative consciousness that warps reality according to its idiosyncratic way of seeing. The point-of-view character of In the Labyrinth is a soldier who is likely feverish and dying; in The Voyeur , a psychotic murderer; in Jealousy, a jealous husband who quite possibly has committed an act of violence or contemplates doing so. In all cases the reader has even more trouble arriving at definitive conclusions than is the case with the presumably very difficult novels of Joyce and Faulkner.

Ultimately, the New Novelists’ program differs in degree more than in kind from the modernist assumption that reality is subjective and that fictional structures should reflect that subjectivity. As famous and frequently discussed as the New Novelists have been, their fiction has had relatively little influence beyond France, and when literary theorists define “postmodernism” (that is, the literary expression that has emerged after, and is truly different from, modernism), they rarely claim the New Novel as postmodern.

Metafiction

A far more significant departure from modernism occurred when writers began to reject the notion that had been dominant among novelists since Miguel de Cervantes: that it is the chief duty of the novelist to be realistic, and the more realistic the fiction the worthier it is. This breakthrough realization—that realism of whatever variety is no more than a preference for a certain set of conventions—manifests itself in different ways in fiction. In metafiction, also known as self-mimesis or selfreferential fiction, the author (or his or her persona), deliberately reminds the reader that the book is a written entity; in the traditional novel, however, the reader is asked to suspend his or her disbelief.

Often the metafictive impulse appears as little more than an intensification of the first-person-omniscient narrator, the “intrusive author” disparaged by Henry James but favored by many nineteenth century writers. Rather than employing an “I” without an identity, as in William Makepeace Thackeray’s Vanity Fair: A Novel Without a Hero (1847-1848), metafiction makes clear that the “I” is the novel’s author. Examples of this technique include the novels of José Donoso in Casa de campo (1978; A House in the Country, 1984) and of Luisa Valenzuela in Cola de lagartija (1983; The Lizard’s Tail, 1983).

In other novels, the metafictive impulse is more radical and transforming. When Donald Barthelme stops the action halfway through Snow White (1967), for example, and requires the reader to answer a fifteen-question quiz on the foregoing, the readers’ ability to “lose themselves” in the novel’s virtual world is hopelessly and hilariously destroyed. Another witty but vastly different metafictive novel is Italo Calvino ’s Se una notte d’inverno un viaggiatore (1979; If on a Winter’s Night a Traveler , 1981), in which the central character, Cavedagna, purchases a novel called If on a Winter’s Night a Traveler by an author named “Italo Calvino.” Cavedagna finds that his copy is defective: The first thirty-two pages are repeated again and again, and the text is not even that of Calvino; it is instead the opening of a Polish spy novel. The remainder of the book concerns Cavedagna’s attempts to find the rest of the spy novel, his blossoming romance with a woman on the same mission, and a rambling intrigue Calvino would surely love to parody had he not invented it. Furthermore, the novel is constructed around a number of openings of other novels that never, for a variety of reasons, progress past the first few pages.

Metafiction is used to represent the impossibility of understanding the global world, particularly the complexity of politics and economics. Critically acclaimed metafictive novels include Australian Peter Carey’s Illywhacker (1985), American Mark Z. Danielewski’s House of Leaves (2000), Canadian Yann Martel’s Life of Pi (2001), and South-African Nobel laureate J. M. Coetzee’s Slow Man (2005). Junot Díaz won the Pulitzer Prize and the National Book Critics Circle Award for his first novel, The Brief Wondrous Life of Oscar Wao (2007). The novel is ostensibly a love story about a Dominican American man in New Jersey, but through a series of extended footnotes and asides the narrator relates and comments on the history of the brutal dictatorship of Rafael Trujillo in the Dominican Republic. The novel has different narrators and settings, as well as occasional messages from the author, and is filled with wordplay and lively slang in English and Spanish.

Fiction as Artifice

One might well ask if metafiction is not too narrow an endeavor to define an age (for example, postmodernism). The answer would be yes, even If on a Winter’s Night a Traveler , for example, might more properly be described as a novel whose subject is reading a novel rather than writing one. Metafiction is best considered one variation of a broader, more pervasive impulse in post-World War II long fiction: fiction-as-artifice. Rather than narrowly focusing on the process of writing fiction (metafiction), in fiction-as-artifice the author directly attacks the conventions of realism or acknowledges that all writing is a verbal construct bearing the most tenuous relationship to actuality.

One of the earliest examples of fiction-as-artifice in the post-World War II canon is Raymond Queneau’s Exercices de style (1947; Exercises in Style , 1958). The title states where Queneau’s interests lie: in technique and in the manipulation of language, rather than in creating an illusion of reality. The book comprises ninety-nine variations on a brief scene between two strangers on a Parisian bus. In each retelling of the incident, Queneau uses a different dialect or style (“Notation” and “Litotes”). The almost endless replication of the single scene forces the reader to see that scene as a verbal construct rather than an approximation of reality. Such “pure” manifestations of fiction-as-artifice as Exercises in Style are relatively rare. More often, fiction-as-artifice is a gesture employed intermittently, side by side with realist techniques. The interplay of the two opposing strategies create a delightful aesthetic friction.

One of the most famous and provocative examples of fiction-as-artifice is Vladimir Nabokov ’s Pale Fire (1962). The structure of the work belies all traditional conventions of the novel. Pale Fire opens with an “editor’s” introduction, followed by a long poem, hundreds of pages of annotations, and an index. The reader discovers, however, that this apparatus tells a hilarious and moving story of political intrigue, murder, and madness. Does Pale Fire , ultimately, underscore the artifices of fiction or, instead, demonstrate how resilient is the writer’s need to tell a story and the reader’s need to read one? Either way, Pale Fire is one of the most inventive and fascinating novels of any genre.

The same questions could be asked of Julio Cortázar’s Rayuela (1963; Hopscotch, 1966), a long novel comprising scores of brief, numbered sections, which, the reader is advised in the introductory “Instructions,” can be read in a number of ways: in the order presented, in a different numbered sequence suggested by the author, or perhaps, if the reader prefers, by “hopscotching” through the novel.

A similar strategy is employed in Milorad Pavic’s Hazarski renik: Roman leksikon u 100,000 reci (1984; Dictionary of the Khazars: A Lexicon Novel in 100,000 Words , 1988). The work is constructed as a dictionary with many brief sections, alphabetized by heading and richly cross-referenced. The reader may read the work from beginning to end, alphabetically, or may follow the cross-references. An added inventive complication is the Dictionary of the Khazars’s two volumes, one “male” and the other “female.” The volumes are identical except for one brief passage, which likely alters the reader’s interpretation of the whole.

Although fiction-as-artifice is European in origin— indeed, it can be traced back to Laurence Sterne’s Tristram Shandy (1759-1767)—its most inventive and varied practitioner is the American writer John Barth . In work after work, Barth employs, parodies, and lays bare for the reader’s contemplation the artifices of fiction.

In his unified collection Lost in the Funhouse (1968), for example, Barth narrates the history—from conception through maturity and decline—of a man, of humankind, and of fiction itself. The story’s telling, however, highlights the artificiality of writing. The first selection (it cannot be called a “story”) of the novel, “Frame Tale,” is a single, incomplete sentence—“Once upon a time there was a story that began”—which is designed to be cut out and pasted together to form a Möbius strip. When assembled, the strip leads to the complete yet infinite and never-ending sentence “Once upon a time there was a story that began Once upon a time. . . .” The novel’s title story, “ Lost in the Funhouse, ” contains graphs illustrating the story’s structure. “Glossolalia” is formed from six brief sections all written in the rhythms of the Lord’s Prayer . In “ Menelaid ,” the dialogue is presented in a dizzying succession of quotation marks within quotation marks within quotation marks. Barth’s experiments in Lost in the Funhouse are continued and intensified in later novels, especially Chimera (1972) and Letters (1979).

In The Broom of the System (1987) by David Foster Wallace, the protagonist, Lenore Stonecipher Beadsman, feels sometimes that she is just a character in a novel. Wallace’s Infinite Jest (1996) is a massive work about a future North America where people become so engrossed in watching a film called Infinite Jest that they lose all interest in other activities. Wallace’s fiction moves back and forth in time without warning and combines wordplay, long sentences, footnotes and endnotes, transcripts, and acronyms to create a disjointed postmodern language.

Mark Dunn’s Ella Minnow Pea: A Progressively Lipogrammatic Epistolary Fable ( 2001) is an epistolary novel about a fictional island off the coast of South Carolina, where the government forbids the use of one letter of the alphabet, at a given time; in effect, the government is parsing the alphabet. The novel is a collection of letters and notes from inhabitants, often less than a page in length, written with a diminishing set of alphabet letters.

Fiction or Nonfiction?

Even at his most experimental, however, Barth never abandons his delight in storytelling. Indeed, virtually all the long fiction addressed thus far show innovations in certain technical strategies but do not substantially challenge the reader’s concept of what is “fictional.” A number of other writers, however, while not always seeming so boldly experimental in technique, have blurred the distinctions between fiction and nonfiction and thus perhaps represent a more fundamental departure from the conventional novel.

The new journalists—such as Truman Capote ( In Cold Blood , 1966), Norman Mailer ( The Armies of the Night: History as a Novel, the Novel as History , 1968), Tom Wolfe ( The Electric Kool-Aid Acid Test , 1968), and Hunter S. Thompson with his Fear and Loathing series (beginning in 1972)—blur the lines between fiction and nonfiction by using novelistic techniques to report facts. However, the subtitle of Mailer’s work notwithstanding, the reader rarely is uncertain what side of the fictionnonfiction line these authors occupy. The same cannot be said for Don DeLillo (Libra, 1988). For his interpretation of the Kennedy assassination, DeLillo spent countless hours researching the voluminous reports of the Warren Commission and other historical documents. With this factual material as the basis for the novel and with assassin Lee Harvey Oswald as the central character, the degree to which Libra can be considered fictional as opposed to nonfictional remains a challenging question.

The question is even more problematic in reference to Maxine Hong Kingston’s The Woman Warrior: Memoirs of a Girlhood Among Ghosts (1976). Kingston conducted her research for her memoir not in library stacks but by plumbing her own memory, especially of stories told her by her mother. At times, Kingston not only is imaginatively enhancing reconstructed scenes but also is inventing details. Is this a work of autobiography or a kind of fiction?

Publishers had trouble classifying Nicholson Baker ’s The Mezzanine (1988) and W. G. Sebald’s Die Ausgewanderten (1992; The Emigrants , 1996). The reader is fairly certain that the point-of-view character in The Mezzanine is fictional, but in what sense is his experience fictional? The work, made up of essaylike contemplations of whatever the persona’s eye falls on as he goes about his business on a mezzanine, recalls in some ways the intensely detailed descriptions of the New Novelists but with even less of an apparent conflict or movement toward climax one expects in fiction.

Sebald’s work is in some ways even odder. His short biographies of a selection of dislocated Europeans have a documentary feel—complete with photographs. The photographs, however, have a vagueness about them that makes them seem almost irrelevant to their subjects, and the reader has the uneasy impression that the book may well be a fabrication.

The distinction between fiction and nonfiction was brought into new relief in 2003, when James Frey published A Million Little Pieces , his memoir of escaping drug addiction. The memoir was aggressively gritty in its detail of the author’s struggles, and Frey was widely praised for his courage and honesty in revealing his own mistakes and weaknesses. In 2005 the book was named to Oprah’s Book Club , and soon after topped nonfiction best-seller lists. In 2006, however, much of the material in the “memoir” was found to have been fabricated. The resulting clamor from talk-show host Oprah Winfrey, Frey’s publishers, and readers led to a lively and interesting public debate over art and truth. Frey claimed that the work presented the “essential truth” of his life. Many readers continued to value the book as an honest accounting of what life is like for some addicts, but readers who felt that they had been defrauded were offered a refund. The Brooklyn Public Library, for example, moved the book to its fiction section.

Just as Baker and Sebald call into question what earlier generations would have thought too obvious to debate—the difference between fiction and nonfiction— one consistent impulse among experimenters in long fiction has been the question, What is necessary in fiction and what is merely conventional? Their efforts to test this question have brought readers some of the most provocative and entertaining works of fiction in the late twentieth and early twenty-first centuries.

BS Johnson with pages from his 1968 novel-in-a-box The Unfortunates , which could be shuffled and read in any order.

Bibliography Currie, Mark, ed. Metafiction. London: Longman, 1995. Collection of articles on experimental themes and techniques. Friedman, Ellen G., and Miriam Fuchs, eds. Breaking the Sequence: Women’s Experimental Fiction. Princeton, N.J.: Princeton University Press, 1989. Levitt, Morton. The Rhetoric of Modernist Fiction from a New Point of View. Hanover, N.H.: University Press of New England, 2006. Robbe-Grillet, Alain. For a New Novel: Essays on Fiction. 1965. New ed. Translated by Richard Howard. Evanston, Ill.: Northwestern University Press, 1996. Seltzer, Alvin J. Chaos in the Novel: The Novel in Chaos. New York: Schocken Books, 1974. Shiach, Morag, ed. The Cambridge Companion to the Modernist Novel. New York: Cambridge University Press, 2007. Waugh, Patricia. Metafiction: The Theory and Practice of Self-Conscious Fiction. New York: Routledge, 2005. Rollyson, Carl. Critical Survey Of Long Fiction. 4th ed. New Jersey: Salem Press, 2010.

The Best Fiction Books » Contemporary Fiction

The best experimental fiction, recommended by rebecca watson.

little scratch by Rebecca Watson

Experimental fiction often uses unusual forms of syntax, style, or form—perhaps taking the form of fragments, footnotes or parallel narratives. Here Rebecca Watson , author of the critically acclaimed experimental novel little scratch , recommends five of the best experimental novels and explains why a writer might choose to bend the rules—and to what effect.

Interview by Cal Flyn , Deputy Editor

When I Hit You: Or, A Portrait of the Writer as a Young Wife by Meena Kandasamy

The Lesser Bohemians by Eimear McBride

Between the Acts by Virginia Woolf

Diary of a Bad Year by J M Coetzee

Dept. of Speculation by Jenny Offill

The Best Experimental Fiction - When I Hit You: Or, A Portrait of the Writer as a Young Wife by Meena Kandasamy

1 When I Hit You: Or, A Portrait of the Writer as a Young Wife by Meena Kandasamy

2 the lesser bohemians by eimear mcbride, 3 between the acts by virginia woolf, 4 diary of a bad year by j m coetzee, 5 dept. of speculation by jenny offill.

T hanks for joining us on Five Books to discuss five of the best examples of experimental fiction. Could you tell us about your own novel little scratch , and its formal invention?

I guess the book is about the way that consciousness works; more specifically, present tense immediacy. That kind of consciousness. I think that it began with the challenge of feeling that prose does not really represent the bombardment and overwhelming simultaneity of everyday live experience. There’s so much going on. But when we write prose, we have this very neat, linear way in which we inhabit a moment. So my challenge was to represent the opposite of that on the page. Trauma can hyper-sensitise the ordinary, so it gave the experiment an extra charge.

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I split the page into channels. It breaks into two or three columns, goes between prose and half-prose. As you go down the page, you pass through time, and you have the internal, the external—sensory information, what you hear, what you smell—and how they, essentially, conflict with but also inform each other. It was kind of a game of association.

One of the things I found so interesting about it, and accurate—at least, according to my own experience of moving through the world—is how the interior monologue can be the defining element of a day. A theatre of drama, or conflict, when outwardly nothing is really happening. But as well as this issue of trauma it also struck me that your book was also fun , in how imaginative it was and how it told little jokes to itself. Do you think that’s important in experimental fiction, that sense of play?

Although perhaps ‘play’ is not the right word for the first book we’re going to discuss? This is When I Hit You by Meena Kandasamy. It’s about quite extreme domestic abuse; a woman marries an Indian intellectual who uses his ideas “as a cover for his own sadism.”

Um, actually I think you can use the word play. It’s uncomfortable, but the beauty of what she does is that she takes an incredibly disturbing centrepiece—this abusive marriage—and turns it into a creative challenge, and a performance.

It’s fiction, with an unnamed first-person narrator, and the narrator is telling the story retrospectively, about five years after these few months of marriage. It’s about how to tell the story: how do you go back and look at something so invasive, so encompassing, while reclaiming, or asserting, your sense of self.

“Experimental writing needs an openness and willingness from a reader, to go beyond what you might be used to”

What is the centre of the book is a playfulness about what it is to be a writer, and what it is to live a life—how we write narratives. And she has this very playful voice that shifts and flirts and diverts. It moves in lots of different registers.

I don’t think it looks experimental on the page. It’s the shifting register that makes it feel really, really new. Kandasamy studies the different vehicles of how to tell a story. The novel moves between prose poetry, to bits where it’s like a Q&A. The narrator is simultaneously the actor who breaks the fourth wall, and the writer dictating the stage directions. So even though we’re looking at this abusive marriage, most of the time this person is almost testing you to see if she can make you laugh, think, shift your expectations of a ‘victim’.

That’s interesting. I’ve actually come to Kandasamy backwards, I think. The first book of hers I read was her novella-memoir hybrid, Exquisite Cadavers . Which was written, I think, in response to how the earlier, highly garlanded novel was received. If When I Hit You does not appear overtly experimental on the page, Exquisite Cadavers certainly is—it’s split into two columns, one strand of which is fictional and the second a sort of metafictional commentary that reflects on her life and the writing process. One expects quite a lot of the reader, when writing in such a form. Or maybe you disagree?

I think we act like there’s more we need from the reader than we actually do. That’s the barrier for people getting into this kind of writing. I think often experimental fiction is used as a warning term rather than as a way of elaborating what the writing is.

Absolutely. The second book you’ve chosen is The Lesser Bohemians by Eimear McBride.

I had to look at this again yesterday, because although I have such a vivid recollection of the feeling of reading it, I couldn’t remember anything about it on a line level! I opened it and thought, ‘wow, so this is what it looks like.’ I guess because it’s so voice-led, you completely enter that head. It’s true consciousness. McBride’s really good at, like, skipping to the image of the association—the kind of narrative preamble, or narrative signposting, that writers often give she will skip, not because she’s trying to be cryptic, but because in real consciousness none of those things exist. You’ve instantly leapt to the next thought or sensation.

It’s a love story between an 18-year-old girl who just moved from Ireland to London to attend drama school, and the older actor she meets in a pub. They slowly unveil their stories to each other, but both are hiding parts of themselves.

Partly it’s about the unknowability of the other, but also the ability to learn so much through love. The lyricism of it is just something else. There’s such a music, such a lilt to it. There’s rhythm and movement to how you read it, any reader would get that. And that’s something incredible to establish.

A lot of people have remarked upon the sexually explicit nature of this book. But one wonders if sex is not perhaps the perfect experience to be rendered as stream of consciousness . I guess I’m also thinking of certain scenes in Ulysses , which McBride herself has talked about as a prime literary influence. But does McBride bring a new approach to this form?

Experimental fiction both points forward and back. We often describe things as new, when they are speaking as part of a tradition. But there is a noticeable newness to this book, and it’s in the deftness of language and the immersion—you feel so entirely in this person’s head whilst also being so clearly told a story. The way she gets inside people’s bodies, and writes sex in such a brilliant, honest and felt way. I think that is genuinely new. And if sex is something that is more instinctive, relies more on sensation and the unifying of desire and the body, then yes, surely experimental fiction serves that best: like sex, it defies a linear, straightforward recounting.

It was a highly anticipated follow up to her very acclaimed debut A Girl is a Half-Formed Thing . How similar are they—as books, as reading experiences?

Next up on our experimental fiction reading list is a Virginia Woolf book I admit I wasn’t familiar with: Between the Acts , her final novel which was published posthumously.

Yes, there’s a split over whether it was finished or not. She never did her final revise of it, and often she did do quite a lot of work in that act of revision. But it doesn’t read like something unfinished. It’s very, very accomplished, and one of my favourite of Woolf’s books.

It takes place at a village pageant in the summer preceding World War Two. I read it as a teenager and was so obsessed with it. I remember getting into an argument with a literature professor at an interview for a university that I very much got rejected from. It was so weird. We both loved Virginia Woolf, but both had very different visions of what that book was. I was young, so sure! I was the naïve one, more likely to be wrong but, at the same time, I remember this man puffing out—because I disagreed with him.

What I was making the case for—and what I still agree with—is how obsessed that book is with the idea of individualism versus society, the exhausting nature of being one person whilst also being so recognisably within the midst of a group, connected to other people.

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I remember him being like, ‘it’s about the war!’ And I was like, I get that it’s about the war, but it’s also about these other things. We just couldn’t connect. I mean, it is about the war, to be fair—so much of it is about the burden of retrospect. It’s just before the war arrives, but they know the war is coming. Another war’s happened already. And so everything’s laced with this very aggressive, violent imagery. There’s something simmering. It’s all about living in what seems a simple present tense that’s about to combust into historical significance.

Let’s talk about J. M. Coetzee’s Diary of a Bad Year next. This is another one that’s pretty interesting to look at on the page. It’s separated into parallel narratives; could you tell us a little about the plot or rather plots, plural?

It begins with the page split into two, horizontally. We have on the top an extract from a book by an old Australian writer, called Strong Opinions . It’s political essays, stuff like that. That’s the top narrative, and initially the bottom narrative is him, first-person, his life as he’s writing the manuscript. Quickly he meets a woman called Anya, in the laundry room of his apartment building. He’s very struck by her, she’s very attractive, she’s a lot younger… there’s something about her that intrigues him. So he asks her to start typing up his manuscript for the book, the first narrative.

Suddenly she appears as a third column, or rather a horizontal division. So now you have the book, his first-person, her first-person. And each informs the others. So you see two perspectives – how she sees him, and how he sees her. He embroils her in his life, but she also embroils herself, because she and her boyfriend start to plot how to insinuate themselves. He’s got a lot of money—maybe they could get some of his cash.

“It sounds very complicated, but it’s incredibly easy to read, and it’s very profound”

You have these interfering narratives, and you can read across the double spread of the page, or down each page. Depending on which way you do it, you learn different things about each of the segments. That sounds very complicated, but it’s incredibly easy to read, and it’s very profound. This guy’s dying, so it’s about being a writer, how to make meaning, and the difference between the creator and the product—seeing this fallible human being behind the authoritative essay.

It does also have a very propulsive story. A classic narrative, of someone thinking they are intentionally bringing someone into their life, and at the same time they are being undone. Who has the power?

Mmm, yes. And this three-stranded form really represents exactly what you were getting at in the start of our conversation: the clarity of prose, the mess of reality. But one thing I suppose I worry about—and maybe other readers worry about this too—when you mention there are multiple ways of reading this book, I guess that allows for the possibility of reading it ‘wrong.’

I think that is often the reader’s fear. I always want to say to people: ‘Hey, don’t worry. Just trust yourself.’ That’s what I say to myself, sometimes. Readers often fear they don’t have the authority to tackle a text. Or just see it as something they have to ‘tackle.’ But a writer doesn’t write something with an authoritative insistence of how it should be read. They lay out a path of how to read it, and you as a reader will follow that – or make your own. little scratch , particularly, exists to be read in different ways, and the reader is meant to make their own choices. Depending on what choice they make, they get different things. That’s the same for Diary of a Bad Year ; those decisions are important, but they’re meant to be fun. They’re not meant to be a stress. The reader should remember that once the book is in their hands, they’re the authority. It’s their reading experience, they’re in control.

Just before we move on, I wanted to read you a quote from the Guardian : “The ensuing comedy of conflicting perspectives, of high rhetoric and low aims, is an amazingly strange thing for Coetzee to have decided to write.” What do you think about that? Is invention itself the aim?

I don’t know. I didn’t think it was strange. I mean maybe, in as much that it’s kind of crazy that it came out of someone’s head. But who are we to say what a writer will write next? And why would we want that to be predictable? The novel is exciting in its formal invention, but as a story in its own right, it’s interesting. The form is a way of getting you closer to the story. It’s not an indulgent thing.

Right, this brings us to our final work of experimental fiction. This is Jenny Offill’s Dept. of Speculation , one of my own top favourite books. I think I’ve read it, honestly, upwards of 100 times. I carry it around on my phone, on my Kindle app, and just reread it on the bus, or anywhere. Do you feel the same? What do you like about it?

It’s quite a hard book to summarise, because it’s so much about those myriad moments that make up a life, or relationship, or anything. Firstly, it’s really funny. People don’t talk directly enough about how funny Jenny Offill is.

It’s essentially about a test of marriage, a kind of imperfect love story. Right? It’s both very sad and very funny.

Right. And it’s told in fragments, each of which are a sentence, or a paragraph, long.

You have these moments between the fragments to take a break, just to laugh, or absorb it. She takes the ordinariness of life and she makes it mean something. I think she proves why every moment of life can have significance, and how the quiet moments of existence contribute to our sense of self.

Last year, when her new book Weather came out, there was a picture of the fragments of Weather , how she’d rearrange them. Seeing that patchwork was amazing, because you can forget when a product is complete that so much work goes into the order of these things. Even just choosing the right ones… there will be so many rejected fragments. It affirmed the level of precision with which she works in order to create these novels.

She’s said that the gaps are moments for the reader to have an imagination. She doesn’t want to fill in the gaps. Because in doing so you eliminate or pin the story down. By fragmenting you allow the reader to immerse themselves in, be part of the world in a more intense way. The absences give the created world a greater imaginative potential.

I really enjoy fragmented fiction, especially this book. But as a style it’s recently become common enough—perhaps riding the wave of Offill’s success—to have inspired a rather funny satire of the form in Lauren Oyler’s new novel Fake Accounts . And of course, you’ve found mainstream success with little scratch. Do you feel like experimental fiction is becoming more influential, more popular?

I don’t know. I think that the fact that little scratch was published and accepted and treated as a novel speaks to a healthy publishing culture. Certainly there’s more space for it and, I think, more commercial viability, which is the key sign that people are open to it.

There’s still a lot of pushback. There’s still a strange treatment of experimental writing. And, you know, when I see people talking about my book, it’s the first thing they do, right? They say, ‘okay, guys, this looks weird, but don’t worry, you’re going to be able to get into it.’ There’s an apology at the beginning. I find that strange. ‘Experimental’ has taken on this negative association. It’s something that we have to forgive, that you can get something from despite it.

I think that kind of negates the whole purpose of this type of writing, which is to help immerse the reader further in the story. It serves a purpose. It’s there to do something beyond looking funny. It’s meant to open up new possibilities. I find it sad that it is often seen as a boundary. We are still very obsessed with keeping that boundary, putting the signpost up. I think we need to work on that.

Do you feel that is anti-intellectual, somehow?

Maybe? I think some readers fear they are being pushed away, or that it’s coded for a certain level of education, rather than for a general reader—which I don’t think is true.

But I think what you were saying earlier about being scared of not approaching the text ‘right’—those kind of insecurities, it’s not that formal or informal education helps you read better, but that maybe it gives you a level of self-trust. Sometimes we need an ego to trust ourselves as a reader. But it’s too complicated to make generalisations. Some think ‘experimental’ fiction is elitist, like it’s trying to shut out a certain reader. But all I can say for myself is that I’m writing for all readers. And I hope little scratch will show some readers who might feel hesitant over formally inventive writing, that shaking up the page can sometimes be a more natural way to read. It might bring you closer, rather than push you away.

April 12, 2021

Five Books aims to keep its book recommendations and interviews up to date. If you are the interviewee and would like to update your choice of books (or even just what you say about them) please email us at [email protected]

Rebecca Watson

Rebecca Watson is the author of little scratch , which is published by Faber in the UK and Doubleday in the US. She was picked as one of The Observer 's ten best debut novelists of 2021. Her work has been published in The TLS, The Guardian, Granta and elsewhere. In 2018, she was shortlisted for the White Review Short Story Prize. She works part-time as assistant arts editor at the Financial Times and lives in London.

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A novel experimental approach to study disobedience to authority

Emilie a. caspar.

1 Moral and Social Brain Lab, Department of Experimental Psychology, Ghent University, Henri Dunantlaan, 2, 9000 Ghent, Belgium

2 Center for Research in Cognition and Neuroscience, Université Libre de Bruxelles, Brussels, Belgium

Associated Data

Data are made available on OSF (DOI: https://doi.org/10.17605/OSF.IO/2BKJC ).

Fifty years after the experiments of Stanley Milgram, the main objective of the present paper is to offer a paradigm that complies with up-to-date ethical standards and that can be adapted to various scientific disciplines, ranging from sociology and (social) psychology to neuroscience. Inspired by subsequent versions of Milgram-like paradigms and by combining the strengths of each, this paper presents a novel experimental approach to the study of (dis)obedience to authority. Volunteers are recruited in pairs and take turns to be ‘agents’ or ‘victims’, making the procedure fully reciprocal. For each trial, the agents receive an order from the experimenter to send a real, mildly painful electric shock to the ‘victim’, thus placing participants in an ecological set-up and avoiding the use of cover stories. Depending on the experimental condition, ‘agents’ receive, or do not receive, a monetary gain and are given, or are not given, an aim to obey the experimenter’s orders. Disobedience here refers to the number of times ‘agents’ refused to deliver the real shock to the ‘victim’. As the paradigm is designed to fit with brain imaging methods, I hope to bring new insights and perspectives in this area of research.

Introduction

The experiment of Stanley Milgram is one of the most (in)famous in psychology 1 , within and beyond academia. Several variables account for this notoriety, such as the method used, the ethical issues associated, the enthralling results or the societal impact of the research topic. Milgram’s classical studies famously suggested a widespread willingness to obey authority, to the point of inflicting irreversible harm to another person just met a few minutes before. Beyond the studies of Milgram, the history of nations is also plagued by horrendous acts of obedience that have caused wars and the loss of countless lives 2 . History has fortunately shown that some individuals do resist the social constraint of receiving orders when their own morality is of greater importance than the social costs associated with defying orders (e.g., 3 , 4 ). To understand the factors that prevent an individual from complying with immoral orders, research on disobedience should focus on two main axes: (1) what social and situational factors support disobedience and (2) what individual differences support disobedience.

The first axe has already been largely investigated in past studies. From Milgram’s studies, important situational factors supporting disobedience have already been established 5 . For instance, disobedience increases if the experimenter is not physically present in the room or if two experimenters provide opposing views regarding the morality of the experiment. Subsequent versions and interpretations of Milgram’s studies 6 – 8 as well as historical research 4 , 9 also suggested the importance of several social (e.g. presence of a supporting group) and situational factors (e.g. family history, proximity with the ‘victim’, intensity of the pain; money) supporting resistance to immoral orders. However, the second axe regarding individual differences has been less systematically approached. A few studies 10 , 11 previously explored personality traits that may influence disobedience (e.g. empathic concern, risk-taking) but most of these studies, however, have used relatively weak and potentially biased methods, such as self-reported questionnaires and methods based on cover stories. These studies are not sufficient to explain why, in a given situation, some people will refuse immoral orders and rescue threatened human beings while others will comply with such orders. With the current literature on disobedience, we have no idea about which neuro-cognitive processes drive inter-individual differences regarding the degree of disobedience. This aim could be achieved by offering a novel experimental approach that would make it possible to use novel techniques that give us a more direct access to the functioning of the brain and cognition, such as functional near-infrared spectroscopy (fNIRS), electroencephalography or Magnetic Resonance Imagery (MRI). Regrettably, the original paradigm and those bearing close similarity are not adapted to reliably answer those questions as they were not designed to fit with neuroimaging measurements. By combining the strengths of previous work on disobedience into a single experimental paradigm and adapting it to fit with cognitive and brain imaging measurements, this novel experimental approach could help to better understand, together with individual, social, and cultural factors, which mechanisms make it possible for an individual to refuse to comply with immoral orders.

There were several challenges to consider in order to develop such a paradigm, both ethical and methodological. Studying obedience and resistance to immoral orders involves putting volunteers in a situation where they have to make a decision on whether or not to commit ‘immoral acts’ under orders. A balance has to be found between what is acceptable from an ethical perspective and what is necessary for the research question. Milgram’s studies on obedience raised undeniable ethical issues 12 – 14 , mostly associated with high stress and the use a cover story, which involves deception. Some variants of Milgram’s studies were realized with immersive virtual reality to prevent the ethical issues associated with Milgram’s paradigm 15 , but the transparency of the fake scenario presented to participants does not capture decision-making in an ecological set-up. Other Milgram-based variants, such as the 150-V method, appear to replicate Milgram’s results 16 with respect to the actual ethical standards, but methodological concerns are still present 17 as cover stories are still used, which lead to interpretation issues. Beyond ethical considerations, the use of deception also indeed involves a doubt about whether or not volunteers truly believed the cover story. As a consequence, a reasonable doubt remains on how to interpret the results and this is one of the main critics associated with Milgram’s studies and following versions. Recent work on the reports of Milgram’s volunteers suggested that there are no strong and reliable evidence that participants believed in the cover story 8 , 14 , 18 . Others suggested that since the stress of participants was visible on video recordings during the experiment (e.g. hand shaking, nervousness), this suggests that participants actually believed that they were torturing another human being 19 . However, this interpretation has been challenged by another study showing that participants can have physiological reactions to stress even in an obviously-fake experimental set-up 15 . These contrasting interpretations of Milgram’s studies actually reinforce the idea that results can hardly be interpreted when cover stories are used 20 . To answer those criticisms, a real scenario had thus to be created, where participants made decisions that have real consequences on another human being.

An additional challenge is that methods relying on the original paradigm of Milgram, such as the virtual reality version 15 or the 150-V method 16 are not adapted to neuroimaging measurements. More specifically, with such Milgram-like experimental approaches, only a single trial would be recorded for the entire experimental session, that is, when the volunteer stops the experiment (if this happens). For cognitive and neuroimaging data collection, a single trial per participant is not a reliable result, which requires the averaging of several trials to obtain a good signal-to-noise ratio.

Another challenge at the methodological and conceptual levels it that several experimenters 1 , 5 , 21 , 22 including myself 21 – 27 , noted that volunteers are extremely obedient when coming to an experiment. Personally, I have tested about 800 volunteers to investigate the mechanisms by which coercive instructions influence individual cognition and moral behaviors. For instance, by using behavioral, electrophysiological and neuroimaging methods, we have observed that when people obey orders to send real shocks to someone else, their sense of agency 23 , their feeling of responsibility 28 , empathy for the pain of the victim and interpersonal guilt 26 are attenuated compared to a situation where they are free to decide which action to execute. Out of 800 volunteers tested, only 27 disobeyed my orders (i.e. 3.3%): 21 for prosocial reasons (i.e. they refused to administer an electric shock to another individual), 3 by contradiction (i.e. by systematically pressing the other button, not matter the content of the order), and 3 for antisocial reasons (i.e. by administering shocks despite my order not to do so). Although convenient to study how obedience affects cognition, this rate is indubitably an issue when studying disobedience. If participants almost never disobey, we can’t study the mechanisms through which resistance to immoral orders may develop in a given situation. Several reasons for not disobeying the experimenter’s orders have been suggested. Some consider that being obedient is part of the human nature as massive and destructive obedience has been observed through countless historical events 2 . Another current view on the experiments of Milgram is that volunteers were actually happy to participate and to contribute to the acquisition of scientific data 17 , thus explaining the high obedience rate observed. This effect has been referred to as ‘engaged followership’ 29 . If that interpretation is correct, the volunteer’s willingness to come and help the experimenter acquiring scientific data creates an extra difficulty to obtain disobedience in an experimental setup. However, this interpretation is challenged by several studies reported by Milgram, which displayed a higher disobedience rate than his original study. For instance disobedience increases when the shocks’ receiver sits in the same room as the participant or when the authoritative experimenter is not physically present in the room 5 . If participants were indeed only guided by their willingness to help to acquire scientific data, this should be the case in any experimental set-up. As some studies involve a higher disobedience rate compared to the initial version of Milgram’s study 1 , they could thus, at a first glance, be used for studying disobedience. However, even if some versions of the initial study of Milgram offer a highly disobedience rate, thus making it possible to study the mechanisms through which resistance to immoral orders may develop in a given situation, these experimental set-ups are still not adapted for cognitive and neuroimaging measurements and still rely on the use of a cover story.

Taking all the presented challenges into account (i.e. not using cover stories to avoid interpretation issues; obtaining a fair rate of disobedience; using an experimental approach that also fits with cognitive and neuroimaging measurements; respecting ethical standards), the present paper presents a set of experiments that combine the strengths of past experimental work on (dis)obedience. Volunteers were openly involved and active (= real social situation) rather than having to act in fictitious scenarios (= imagined social situation, e.g. Slater et al., 2006). They were confronted with moral decisions to follow or not the orders from an experimenter to inflict a real painful shock to a ‘victim’ in exchange (or not) for a small monetary gain, thus avoiding the use of cover stories. Since the aim here is to develop a paradigm that could be used both in behavioral and neuroimaging studies, some basic characteristics had to be considered. For instance, to fit with a Magnetic Resonance Imagery (MRI) scanning environment, neither the ‘victim’, nor the experimenter were in the same room as the agent. A real-time video was thus used to display a video of the victim’s hand receiving shocks on the agent’s screen and headphones were used so the participant could hear the experimenter’s orders.

Another method to study disobedience would be to select participants who are more likely to disobey than others. Each volunteer was thus also asked to complete a series of personality questionnaires to evaluate if a specific profile is associated with a greater prosocial disobedience rate. Systematic post-experimental interviews were conducted at the end of each experiment in order to understand the decisions of volunteers to follow or not the orders of the experimenter and to ask them how they felt during the experiment.

Participants

A hundred eighty naive volunteers (94 females) were recruited in same gender dyads (= 90 dyads). During the recruitment procedure, I ensured that the participants in each dyad were neither close friends (by mixing people studying different academic courses), nor relatives. To estimate the sample size a priori, I calculated the total sample size based on an effect size f of (0.3). To achieve a power of 0.85 for this effect size, the estimated sample size was 168 for 6 groups 30 . I increased the sample size slightly to 180 in order to prevent loss of data in case of withdrawals. Volunteers were randomly assigned to one of the 6 variants of the task (N = 30/variant). One volunteer was not taken into account because they only played the role of the ‘victim’ to replace a participant who did not show up. No volunteers withdrew from the experiment. For the remaining 179 volunteers, the mean age was 22.63 years old (SD = 2.77, range:18–35). A Univariate ANOVA with Age as the dependent variable and Variant as the fixed factor confirmed that age of the volunteers did not differ between the different variant of the tasks ( p > 0.1, BF 10 = 0.167). Volunteers received between €10 and €19.60 for their participation. All volunteers provided written informed consent prior to the experiment. The study was approved by the Ethics Committee of the Erasme Hospital (reference number: P2019/484). All methods were performed in accordance with the relevant guidelines and regulations.

Method and Material

Six experimental set-ups were created in a between-subject design. In all six set-ups, volunteers were invited by pairs. One person was assigned to start as agent and the other one to start as ‘victim’. Their roles were switched mid-way, ensuring reciprocity. Compared to the experimental design of Milgram, both volunteers were real participants, not confederates. The reciprocity also avoided volunteers to be stuck in the role of the person providing pain to the other, thus attenuating the potential psychological distress of being in a perpetrator role only. Volunteers were given the possibility to choose the role they wanted to start with. In the case none of them had a preference, role assignment was decided by a coin flip, but volunteers were reminded that they could still decide themselves. This procedure allows to ensure that participants do not think that this procedure is a trick.

Volunteers were first given the instructions of the task. Then, they signed the consent forms in front of each other, so both were aware of the other’s consent. The experimenter was never present in the same room, but rather gave the instructions through headphones. This was for two reasons. First, Milgram’s studies show that disobedience increases if the experimenter is not physically present in the room. Second, in the case of MRI scanning, the experimenter would not be able to give direct verbal instructions to the volunteers in the MRI room due to the high noise of the scanner. Here, agents were isolated in a room and were provided headphones to hear the experimenter’s instructions (see Fig. 1 ). They were told that this was done to avoid attentional interferences through the experimenter’s physical presence in the room. In this series of studies, instructions were pre-recorded but a real setup with a microphone connected to the headphones could also work. Pre-recordings allow perfect timing of the events, important for neuroimaging or electroencephalography recordings. The instructions were “ give a shock ” or “ don’t give a shock ”. To increase the authenticity of the procedure, each sentence was recorded 6 times with small variations in the voice and displayed randomly. In addition, the audio recordings included a background sound similar to interphone communications.

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Experimental setup. Schematic representation of the experimental setup. Volunteers were in different rooms. The experimenter was located in a third, separated room. The agent heard on a trial basis the orders of the experiment through headphones and had to decide to press the ‘SHOCK’ or ‘NO SHOCK’ button. A real-time camera feedback displayed the hand of the victim of the agent’s screen so to allow to keep track on the consequences of their actions.

Shocks were delivered using a constant current stimulator (Digitimer DS7A) connected to two electrodes placed on the back of victims’ left hand, visible to the agent through the camera display. Individual pain thresholds were determined for the two volunteers before starting the experiment. This threshold was determined by increasing stimulation in steps of 1 mA (Caspar et al., 2016). I approximated an appropriate threshold by asking a series of questions about their pain perception during the calibration (1. « Is it uncomfortable? »—2. « Is it painful? »—3. « Could you cope with a maximum of 100 of these shocks? »—4. « Could I increase the threshold? »). When roles were reversed, I briefly re-calibrated the pain threshold of the new victim by increasing the stimulation again from 0 in steps of 3 mA up to the previously determined threshold, to confirm that the initial estimate was still appropriate, and to allow re-familiarisation. The mean stimulation level selected by this procedure was 36.3 mA (SD = 17.5, V = 300, pulse duration: 200 µs). I chose this instead of other types of pain (e.g. financial) because it produces a clear muscle twitch on the victim’s hand each time a shock is sent. This allows volunteers to have a clear and visible feedback of the consequences of their actions and to be fully aware that shocks were real.

There was a total of 96 trials per experimental condition. In the coerced condition, the experimenter asked to give a shock in 64 trials and asked not to give a shock 32 trials. This ratio was chosen on the assumption that the volunteer’s willingness to refuse immoral orders would increase with the number of times they were instructed to inflict pain to the “victim”.

On each trial, a picture of two rectangles, a red one labelled ‘SHOCK’ and a green one labelled ‘NO SHOCK’, was displayed in the bottom left and right of the screen. The key-outcome mapping varied randomly on a trial-wise basis, but the outcome was always fully congruent with the mapping seen by the participant. Agents could then press one of the two buttons. Pressing the SHOCK key delivered a shock to the victim while pressing the NO SHOCK key did not deliver any shocks. This procedure of randomized button mapping allows to have a better control over motor preparation, an aspect that can be important for neuroimaging data.

In half of the variants of the task (i.e., 3/6), the “Aim” variants, participants were given a reason for obeying the orders of the experimenter, while this was not the case in the other half, the “No aim” variants. In the “No Aim” variants, I did not provide any reasons for obeying to the participants and I simply explained the task. If participants asked about the aim, I simply told them that they would know at the end of the experiment, without providing further justifications. In the “Aim” variants, volunteers were told that researchers observed a specific brain activity in the motor cortex in another study when participants were given instructions. We explained that the present study was a control study to measure different aspects linked to motor activity when they press buttons, in order to see if the button pressing was related to brain activity measured over the motor cortex. To increase the veracity of the aim, electrodes were also placed on their fingers and connected to a real electromyography (EMG) apparatus to supposedly record their muscle activity. Volunteers were instructed to press the two buttons only with their right and left index fingers, as naturally as possible, and to avoid producing too ample movements to create clean EMG data. In the case volunteers asked if they really had to follow orders, I told them that for ethical reasons I could not force them to do anything, but that it would be better for the sake of the experiment. Telling them explicitly that they could disobey the orders would not be beneficial in the quest of studying ‘real’ disobedience.

In 4 out of 6 variants of the task, the “Free-choice” variants, a second experimental condition was used, the free-choice condition. In this condition, volunteers were told that they could freely decide in each trial to shock the ‘victim’ or not. In this condition, they did not receive instructions. In 4 out of 6 variants of the task, the “Monetary reward” variants, agents received a monetary reward of + €0.05 for each shock delivered. In the other 2 variants, volunteers were not rewarded for each shock delivered (i.e. “No monetary reward” variants). To resume, the 6 variants of the same task were the following: (1) No Aim + Monetary reward + Free-choice condition; (2) No Aim + No monetary reward + Free-choice condition; (3) Aim + Monetary reward + Free-choice condition; (4) Aim + No monetary reward + Free-choice condition; (5) No Aim + Monetary reward + No free-choice condition; (6) Aim + Monetary reward + No free-choice condition (see Table Table1 1 ).

Schematic representation of each variant of the experimental task.

Variants of the task	Aim for obedience	Monetary reward	Free-choice condition
Variant 1	✗	✓	✓
Variant 2	✗	✗	✓
Variant 3	✓	✓	✓
Variant 4	✓	✗	✓
Variant 5	✗	✓	✗
Variant 6	✓	✓	✗

Before the experimental session, volunteers filled in six questionnaires. Those questionnaires included (1) the Money Attitude Scale (e.g. “ I put money aside on a regular basis for the future ”) 31 , (2) the Moral Foundation Questionnaire (e.g. “ Whether or not someone showed a lack of respect for authority ”) 32 , (3) the Aggression-Submission-Conventionalism scale (e.g., “ We should believe what our leaders tell us ”) 33 , (4) the short dark triad scale (e.g., “ Most people can be manipulated ”) 34 , the Interpersonal Reactivity Index (e.g. “ When I see someone get hurt, I tend to remain calm ”) 35 . At the end of the experimental session, they were asked to fill in two more questionnaires: (1) A debriefing assessing what they felt during the experiment and the reasons for choosing to obey or disobey the orders of the experimenter (Supplementary Information S1) and (2) a questionnaire on social identification with the experimenter (e.g., “ I feel strong ties with this experimenter ”) 36 . At the end of the experiment a debriefing was conducted for each volunteer, separately. Volunteers were then paid, again separately.

General data analyses

Each result was analyzed with both frequentist and Bayesian statistics 37 . Bayesian statistics assess the likelihood of the data under both the null and the alternative hypothesis. BF 10 corresponds to the p (data| H 1 )/ p (data| H 0 ). Generally, a BF between 1/3 and 3 indicates that the data is similarly likely under the H 1 and H 0 , and that the data does not adjudicate which is more likely. A BF 10 below 1/3 or above 3 is interpreted as supporting H 0 and H 1 , respectively. For instance, BF 10 = 20 would mean that the data are 20 times more likely under H 1 than H 0 providing very strong support for H 1 , while BF 10 = 0.05 would mean that the data are 20 times more likely under H 0 than H 1 providing very strong support for H 0 38 . BF and p values were calculated using JASP 39 and the default priors implemented in JASP. All analyses were two-tailed.

Number of shocks given in the free-choice condition

In the free-choice condition, volunteers were told that they were entirely free to decide to deliver a shock or not to the ‘victim’ on each of the 96 free-choice trials. On average, agents administered shocks to the victim on 31.86% of the trials (SD = 34.98, minimum: 0%, maximum: 100%) in the free-choice condition, corresponding to 30.59/96 shocks. A paired-sample t-test indicated that agents delivered less frequently a shock in the free-choice condition than in the coerced condition (68.03%, SD = 41.11, t (119) = -9.919, p < 0.001, Cohen’s d = − 0.906, BF 10 = 1.987e + 14). This result supports the fact that individuals can inflict more harm to others when they obey orders than when they act freely.

Prosocial disobedience across variants

In the present study, I was interested in prosocial disobedience, that is, when agents refuse the orders of the experimenter to send a painful shock to the ‘victim’. Table Table2 2 displays the number of volunteers who reported that they voluntarily disobeyed in each variant of the task.

Number of volunteers who reported that they voluntarily disobeyed the orders of the experimenter.

	Variant 1	Variant 2	Variant 3	Variant 4	Variant 5	Variant 6
Voluntary disobedience (‘Yes’)	23/30	24/30	8/30	16/30	24/30	13/30

In this experiment, the main variable of interest was not to consider how many participants disobeyed in each variant only, but also how frequently they disobeyed. A percentage of prosocial disobedience was calculated for each volunteer, corresponding to the number of trials in which participants chose to disobey (i.e., sending no shocks while ordered by the experimenter to do so) divided by the total number of trials corresponding to the order to send a shock, multiplied by 100. I compared the prosocial disobedience rate across variants of the task, gender of participants and order of the role. I conducted a univariate ANOVA with prosocial disobedience as the dependent variable and Aim (aim given, no aim given), Monetary reward (+ €0.05 or not), Free-choice (presence or absence of a free-choice condition), Gender and Order of the Role (agent first, victim first) as fixed factors (see Fig. 2 ). Both frequentist and Bayesian statistics strongly supported a main effect of Aim (F (1,155) = 14.248, p < 0.001, η 2 partial = 0.084, BF incl = 158.806). Prosocial disobedience was lower when an aim for obedience was given to volunteers (20.4%, CI 95 = 12.8–28.1) than when no aim was given (43.3%, CI 95 = 35.6–51). Both frequentist and Bayesian statistics also supported a main effect of Monetary reward (F (1,155) = 12.335, p = 0.001, η 2 partial = 0.074, BF incl = 28.930). Prosocial disobedience was lower when a monetary reward was given for each shock (25.1%, CI 95 = 18.5–31.7) than when no monetary reward was given (45.4%, CI 95 = 35.9–54.8). The frequentist approach showed a main effect of Gender (F (1,155) = 5.128, p = 0.025, η 2 partial = 0.032), with a lower prosocial disobedience rate for female volunteers (25.7%, CI 95 = 18.2–33.2) then for male volunteers (38%, CI 95 = 30–46). However, the Bayesian version of the same analysis revealed a lack of sensitivity (BF incl = 0.871). All other main effects or interactions supported H 0 or a lack of sensitivity (all p s > 0.1 & BFs incl ≥ 0.4.291E-7 & ≤ 1.178).

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Graphical representation of the percentages of prosocial disobedience in each variant of the task.

The following results report two-tailed Pearson correlations between prosocial disobedience and several other variables, including (1) the reasons given for disobeying, (2) the feeling of responsibility, badness and how sorry they experienced during the experiment, (3) the identification with the experimenter, (4) the perceived level of pain of the victim, (5) identification with the ‘victim’, and (6) individual differences measured through self-report questionnaires. I applied a False Discovery Rate (FDR) approach with the Benjamini and Hochberg method 40 to each p-value for each of those correlations but for the sake of clarity these variables are reported in different sub-sections.

Reasons for prosocial disobedience

All participants who reported that they voluntarily disobeyed the orders of the experimenter (N = 108) were presented a list of 10 reasons that they had to rate from “Not at all” to “Extremely” (see Supplementary Information S1). The reason ‘ I wanted to make more money ’ was only considered for the data of volunteers who had a variant with a monetary reward for each shock (N = 68). Both frequentist and Bayesian statistics showed that the percentage of prosocial disobedience positively correlated with moral reasons (r = 0.550, p FDR < 0.001, BF 10 = 1.700e + 7), positively correlated with disobedience by contradiction (r = 0.329, p FDR < 0.001, BF 10 = 47.53) and negatively correlated with the willingness to make more money (r = − 0.485, p FDR < 0.001, BF 10 = 822.16). Other correlations were in favor of H 0 or were inconclusive (all p s FDR > 0.076, all BFs 10 ≥ 0.120 & ≤ 1.446).

Feeling responsible, bad and sorry

Both frequentist and Bayesian statistics showed strong positive correlations between prosocial disobedience and how responsible (r = 0.299, p FDR < 0.001, BF 10 = 343.98) and how bad (r = 0.301, p FDR < 0.001, BF 10 = 384.65) they felt during the task (see Figs. 3 A and B). The more responsible and worse they felt during the task, the more they refused the order to send a shock to the ‘victim’. How sorry they felt was inconclusive ( p FDR > 0.08, BF 10 = 0.929).

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Graphical representation of Pearson correlations between prosocial disobedience and ( A ) feeling of responsibility, ( B ) how bad agents felt during the task when they administered shocks to the ‘victim’, and ( C ) how painful they estimated the shock delivered to the ‘victim’ was. All tests were two-tailed.

Identification with the experimenter

Both frequentist and Bayesian statistics strongly supported H 0 regarding the relationship between prosocial disobedience and personal identification ( p FDR > 0.5, BF 10 = 0.121) and bonding with the experimenter ( p FDR > 0.5, BF 10 = 0.117). The relationship between the charisma of the experimenter and prosocial disobedience was also slightly in favor of H 0 ( p FDR > 0.1, BF 10 = 0.530).

Estimated pain of the ‘victim’

The frequentist approach showed a positive correlation between the perceived pain of the ‘victim’ and prosocial disobedience (r = 0.189, p FDR = 0.048). The higher they considered the ‘victim’ to be in pain, the more frequently they refused to deliver the shock. The Bayesian version of the same analysis slightly supported this relationship (BF 10 = 2.236), see Fig. 3 C.

Identification with the ‘victim’

In the post-session questionnaire, volunteers had to identify to what extent they considered that the other participant could be part of their group and to what extent they identified with the other participant. Both frequentist and Bayesian statistics strongly supported H 0 regarding the relationship between prosocial disobedience and the perception that the other participant could be part of one’s own group ( p FDR > 0.8, BF 10 = 0.096). The relationship between prosocial disobedience and the identification with the other participant also slightly supported H 0 ( p FDR > 0.1, BF 10 = 0.511).

Correlations between the behavior of pairs of participants

As we used a role reversal procedure, the behavior of those who were agents first could influence the behavior of those who turned agents afterwards. A Pearson correlation between prosocial disobedience of agents first and prosocial disobedience of victims who turned agents afterwards. The correlation was positive (r = 0.514, p < 0.001, BF 10 = 60,068.704), suggesting participants who were agents second tend to act similarly as those who were agents first.

Individual differences associated with prosocial disobedience

Another approach to ensure a reliable prosocial disobedience rate when recruiting volunteers would be to target individuals with a profile that is most frequently associated with disobedient behaviors. Both frequentist and Bayesian statistics for exploratory correlations were two-tailed. Cronbach’s α for each subscale is presented in Supplementary Information S2. Both frequentist and Bayesian statistics showed a negative correlation between scores on the Authority subscale (r = -0.259, p FDR < 0.001, BF 10 = 41.372) and the Purity subscale (r = -0.303, p FDR < 0.001, BF 10 = 424.97) from the MFQ questionnaire. The lower volunteers scored on authority and purity, the higher was their prosocial disobedience rate. Other correlations were in favor of H 0 or were inconclusive (all p s FDR ≥ 0.048, all BFs 10 ≥ 0.100 & ≤ 2.314).

Reasons for obedience

If participants reported that they did not voluntarily disobey the orders of the experimenter, they were asked in an open question to explain their decision to comply with those orders. After reading all the answers, three categories were extracted from the reasons provided: (1) ‘For science’ reasons; participants reported that they obeyed to allow reliable data acquisition (e.g., Participant 91: “ Pour ne pas fausser l’étude ”—English translation: “ To avoid biasing the stud y”); (2) ‘For respect of authority’ reasons; participants reported that they had to follow the orders of the authoritative figure (e.g., Participant 13: “ Pour moi c’est normal de suivre un ordre ”—English translation: “ In my opinion, it’s normal to follow an order ”), and (3) ‘For lack of side-effects’ reasons; participants reported that since the shocks delivered were calibrated on one’s own pain threshold, obeying orders to shock was not problematic (e.g., Participant 115: “ Douleur supportable pour l'autre, je n'ai accepté de faire subir que ce que j'aurais été prêt à subir moi-même ”—English translation: “ The pain was tolerable for the other participant, I have accepted to inflict the intensity of the pain that I would have been ready to undergo myself ”). An independent, naive judge classified the response of participants in one or several of those three established categories. Analyses of the frequencies revealed that the reason “For Science” was mentioned 31/70 times, the reason “For lack of side-effects” was mentioned 17/70 times and the reason “For respect of authority” was mentioned 31/70 times.

The aim of the present paper was to present a novel experimental approach to study (dis)obedience to immoral orders, by combining the strength of past experimental work and by adapting it to cognitive and neuroimaging measurements. Although other versions were proposed since Milgram’s studies, like a study in an immersive virtual environment 15 or the 150-V method 16 , some methodological concerns remained as those methods still involved cover stories or fake experimental set-ups. Here, the experimental approach was significantly different as it was based on an entirely transparent method that involved the administration of real electric shocks to another individual. This approach has the advantage to solve some of the main ethical and methodological concerns associated with the use of cover stories. It also has the advantage that it be can used both to study how social and situational factors influence disobedience as well as individual factors. For social and situational factors, the proposed paradigm can be adapted to evaluate for instance the influence of a supporting group, the use of high or low monetary rewards or how priming disobedience with a documentary influence disobedience. For individual factors, the paradigm allows to investigate how personality traits influence disobedience or to study the neuro-cognitive processes underlying disobedience.

Some novel theories combining a multi-method approach based on social psychology, neuroeconomics and neuroscience could thus emerge to understand better the mechanisms supporting disobedience. For instance, one could evaluate how empathy for the pain of the victim predicts disobedience and how the presence of a supporting group influences our capacity to feel empathy 41 and/or compassion for the ‘victim’ 42 . It could also be argued that the presence of a supporting group diffuses responsibility between individuals and increases obedience, by influencing how our brain processes agency and responsibility over our actions 28 , 43 – 45 . As the results obtained in the present study also indicated that feeling bad for the shocks delivered was statistically associated with prosocial disobedience, one could evaluate how the neural correlates of guilt 46 predicts prosocial disobedience and what historical, cultural and individual factors influence the feeling of guilt.

Six variants of the same task were tested in the present study, some inducing a higher prosocial disobedience rate than others. Statistical results showed that providing a reason—or aim—to justify obedience strongly decreased disobedience. Providing a monetary reward, even one as small as €0.05, also strongly decreased disobedience. Variant 2, in which volunteers were not given an aim or monetary reward, showed the highest disobedience rates. However, to study disobedience in ecological way, the paradigm should capture disobedience of participants even if they know that they are losing something (i.e., monetary rewards or the ‘trust’ of the experimenter asking them help for the study). Defying the orders of an authority generally involves social and/or monetary costs in real-life situations. I would thus not recommend using an experimental paradigm in which volunteers have no costs associated with defying the orders of the experimenter, as it would reduce the ecology of the disobedience act. Variants 3 and 6 involve two types of costs for resisting the orders of the experimenter: a monetary loss and deceiving the experimenter. In Variant 3, descriptive statistics showed that prosocial disobedience was lower compared to Variant 6. The main difference between these two variants was the presence of a free-choice condition. In my former studies 23 , 27 , volunteers frequently justified obedience in the coerced condition because they were given freedom in the free-choice condition (e.g. Participant 89 – English Translation: “ (…) In addition, I knew I could chose freely in the other condition not to send shocks—what I did ). In the present debriefings, some volunteers also reported that the presence of a free-choice condition was giving them enough freedom to accept to follow the orders in the coerced condition. In the supplementary analyses, results showed that when the monetary reward and the aim for obeying are identical, being given a free-choice condition reduces disobedience in the coerced condition. Therefore, Variant 6 appears to provide a good balance between reaching a reliable disobedience rate and finding volunteers who would refuse to produce physical harm on another human beings despite the monetary or social costs associated with defying orders.

Another approach would be to pre-select people who are predicted to be more disobedient. Personality questionnaires indicated that scoring low on the authority and on the purity subscale of the MFQ was strongly associated with a higher prosocial disobedience rate. The link between one’s own relationship to authority and prosocial disobedience observed here replicates another study conducted on the first generation of Rwandese after the 1994 genocide 47 . One’s own relationship to authority thus appears to be a reliable predictor variable in order to pre-select a sample that is more likely to disobey immoral orders.

In the present paper, administering a real mildly painful shock in exchange or not for a small monetary gain was described as an ‘immoral’ act. The notion of what is moral or not can highly differ between individuals 48 , for both academics and volunteers participating in an experiment. Humans are indeed sensitive to different competing issues of morality, a key reason for rescuing persecuted people 49 . In accordance with this observation, the present results indicated that moral reasons were a critical factor associated with the prosocial disobedience rate: the more shocking partners was considered as immoral, the more volunteers disobeyed. However, considering an action as against one’s own moral values does not necessarily translate to a refusal—especially when this order is in line with the Law. An extreme example is soldiers who have perpetrated acts that transgressed their moral beliefs but were issued by their superior in combat 50 . A core question for future research remains: Why are some people capable of putting their own moral standards above the social costs associated with defying orders?

Results indicate that the more volunteers felt responsible during the task, and the worse they felt for sending shocks to the ‘victim’, the higher was their prosocial disobedience. In another study, we observed that obeying orders reduced the feeling of responsibility, how bad and how sorry volunteers felt compared to being free to decide 26 . One hypothesis is that individuals who have preserved a feeling of responsibility and feeling bad—even under command—could more easily defy immoral orders. However, future studies are necessary to better understand the neuro-cognitive processes that prevent an individual from complying with immoral orders. As this paradigm is adapted to neuroimaging measurements, a whole range of studies could now be conducted.

It has been previously suggested that a strong identification with the experimenter giving orders is associated with higher obedience 36 . However, in the present paper, correlations between prosocial disobedience and identification with the experimenter were in favor of H0 with both the frequentist and the Bayesian approaches. In a former study, we also observed that identification to the experimenter was not a critical aspect for explain (dis)obedience. We observed that the generation of Rwandese born after the genocide and tested in Rwanda reported a higher identification to the experimenter than the same generation of Rwandese but tested in Belgium 47 . However, the latter group had a higher prosocial disobedience rate than the former group. Future studies must thus be conducted to understand how the identification with the person giving orders could influence obedience and its weight compared to other social, cultural and individual variables.

Although some volunteers reported that they felt a bit stressed and anxious during the task when they were in the role of the agent, the overwhelming majority did not report any negative psychological feelings. None of the participants withdrew from the experiment and none reported long-term negative psychological effects.

Nowadays, it has become difficult to find volunteers who do not know Milgram’s studies given the high media coverage, including movies, radio soaps, books, podcast and documentaries. One could expect that knowing Milgram would prevent people to obey. However, for the large majority of volunteers, it appears that this is not the case. In previous studies that I conducted with a relatively similar paradigm, the disobedience rate was drastically low (i.e. 3.3%) even if participants were university students knowing Milgram’s studies. In the present study, almost all the volunteers who participated in the present study knew Milgram and explicitly mentioned him during the oral debriefings or before starting the experiment. Yet for those who disobeyed, almost none reported that the reason for disobedience was that they thought it was the aim of the experiment. Further, there was no statistical relationship between prosocial disobedience and believing that it was the aim of the study. It does not mean that knowing Milgram would not influence at all disobedience. It rather suggests that knowing Milgram is not the main factor influencing one’s decision to obey or not an experimenter. It is also possible that since in this experiment shocks were real and not fake such as in Milgram’s studies, participants considered that this was indeed not a study aiming to replicate Milgram.

As far as I have observed, the main problem associated with knowing Milgram’s studies is that volunteers believe that I also have hidden aims and procedures when they enter the experimental room. Several volunteers reported that they only realized that my explanations for the task were true when they were explicitly offered the choice to decide which role to play first and/or when they started receiving the shocks. This is a general concern in psychological studies: The high use of cover stories can also impact other research, as volunteers start to develop a mistrust in what researchers tell them.

Results indicated that who were agents second tend to act similarly as those who were agents first, by sending a relatively similar amount of shocks. Of note, this is an effect that we also observed in past studies on the effect of obeying orders on cognition 23 , 26 , 43 . Nonetheless, in none of those studies we observed that the order of the role had a statistical influence on the neuro-cognitive processes targeted. However, the influence on role reversal on disobedience and related neuro-cognitive processes has still to be investigated in future studies.

The present paradigm is ecological in the sense that volunteers are facing decisions that have a real, physical impact on another human being. However, at the moment I only have little evidences that this paradigm has ecological validity to reflect obedience in real life situations, especially regarding “destructive disobedience” 17 . Caution is indicated when making inference from laboratory studies to complex social behaviours, such as those observed during genocides 16 . My main evidence at the moment is that the very low rate of prosocial disobedience observed in the first generation of post-genocide Rwandans tested in Rwanda using this paradigm 47 is consistent with the fact that deference to authority had already been emphasized by academics as an important factor in the 1994 genocide 4 , 51 . Individual scores on deference to authority in Caspar et al. 47 was the best predictive factor for prosocial disobedience in that former paradigm, thus suggesting some ecological validity. A promising approach would be to recruit “Righteous Among the Nations”, individuals who really saved lives during genocides. Testing this population with the present paradigm would put the ecological validity of this paradigm to the test.

People’s ability to question and resist immoral orders is a fundamental aspect of individual autonomy and of successful societies. As Howard Zinn famously wrote: “ Historically, the most terrible things—war, genocide, and slavery—have resulted not from disobedience, but from obedience ”. Understanding how individuals differ in the extent to which they comply with orders has undeniably several societal implications. They range from understanding how evolving in highly hierarchical environments — such as the military or prisons—influences moral behaviours, to developing interventions that would help to prevent blind obedience and help to resist calls to violence in vulnerable societies. However, since Milgram’s studies, the topic of disobedience has been mostly studied by social psychologists using adapted versions of the initial paradigm developed by Milgram. I hope that with this novel approach, (dis)obedience research will be given a new boost and will be considered by other scientific disciplines seeking to understand better human behaviours.

Supplementary Information

Acknowledgements.

Emilie A. Caspar was funded by the F.R.S-FNRS.

Author contributions

E.A.C. developed the study concept and the method. Testing, data collection and data analysis were performed by E.A.C. E.A.C. wrote the manuscript.

Data availability

Competing interests.

The author declares no competing interests.

Publisher's note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

The online version contains supplementary material available at 10.1038/s41598-021-02334-8.

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Renaissance of the Weird: Experimental Fiction as the New American Normal

John domini on amber sparks, percival everett, laura van den berg, lance olsen, paul beatty, karen russell, and more.

So you pick up a New Yorker short story, hoping to find something fresh. Here’s one that seems to have gotten a lot of attention, “The Ghost Birds,” by Karen Russell. In no time you find yourself spellbound, swept up in a world where no one would want to live, a near-future biosphere so toxic it’s killed off all the birds. Gloomy stuff indeed, and yet you turn pages or swipe screens fascinated, compelled in large part by the sheer strangeness.

Russell will kick off a section with an arresting line like “To be a kid requires difficult detective work,” thereby opening an alternative point of view for which the only correlative might be the children’s barracks at Auschwitz. She’ll interrupt the narrative with lists of the bird species lost, or with flashbacks so compelling, they could be whole novels in thumbnail: “The fires spread to every continent. The air turned a peppery orange, making each unfiltered breath a harrowing event.” At the story’s climax, things turn supernatural, decidedly ambiguous, and to confirm the outcome, you need to reread a fleeting earlier reference or two.

A magnificent piece of work, “The Ghost Birds” depends—for its impact—on stretching, not to say manhandling, the fictional form. It bears little resemblance to what’s generally considered “a New Yorker story,” the strained domesticity of contributors from John O’Hara to Ann Beattie. At the same time, despite its future tech and apocalyptic apparatus, Russell’s piece doesn’t feel right for, say, Fantasy & Science Fiction . It achieves both emotional sting and political savvy (a harsh critique of capitalism) beyond what’s generally considered SF turf, the materials of Asimov and Bradbury.

But then again, who cares what’s “generally considered?” Don’t perceptions like that always wind up off-base, whether the subject’s the New Yorker or F&SF ? These days, Hugo and Nebula winners claim the proud heritage of George Orwell and Mary Shelley, and many prefer to call their genre “spec-fic,” if not “cli-fi.” That last category, fiction about the climate crisis, seems the best fit for Russell’s splendid work⎯insofar as it needs a fit.

“Ghost Birds” succeeds by defying any such demands, disrupting the norms of dramaturgy, and so makes an excellent introduction to my larger point. I’d argue that nothing so animates contemporary American novels and short stories as the spirit of experiment. Experimental fiction is flourishing, as we near the century’s quarter-mark, in a way this country has rarely if ever seen.

The evidence lies scattered far and wide, so easy to spot that I’m baffled by how little critics have noticed. Granted, the term “experimental” still turns up, most often applied to esteemed elders like Don DeLillo. Yet the same energy crackles, unmistakably, in a good many talents now in mid-career, if not just hitting their stride.

The outstanding case in point would be Colson Whitehead; the novel that may rank as his most celebrated, The Underground Railroad, also presents his wildest Rube Goldberg contraption. And Whitehead hardly stands alone. Even setting aside the so-called Afrofuturists, like N.K. Jemisin and her alternative worlds, many of the recent knockout fictions from Black Americans display a glittering eccentric streak. You spot it even in texts very different from Whitehead’s, like Paul Beatty’s The Sellout (2015) . Then there’s the prolific Percival Everett, lower profile but always in some way iconoclastic.

Naturally, the phenomenon is more common in the smaller independent houses, like Fiction Collective 2, Two Dollar Radio, or Dzanc. Among these, Lance Olsen would be the exemplar, now into his third decade of narrative chimera. But a number are with commercial houses, among them some of the country’s most exciting women authors. Alongside Russell, I’d put Amber Sparks and Laura van den Berg.

In short, there’s a lot of activity. Naturally, it hasn’t spread everywhere or changed everything. Telling your story strangely, in a literary culture of such variety, has by no means become the only way for an American to work. Still, an awful lot of writers are embracing the strange, impatient with established standards and practices. I daresay such titles dominate the New Fiction shelves these days, and certainly the work has won notice, including more than a few awards. Still, no one has stood up to raise a shout, a salute, and this leaves it up to me, I suppose⎯a toast to our Renaissance of the Weird.

More than celebration, to be sure, my essay intends illumination. I’ll start abroad, in Europe particularly, considering how it treats narrative rowdiness, and then I’ll draw out the contrast to the situation Stateside, our long-troubled relationship with such work. Once I’ve established that difference, that history, I’ll return to the contemporary, a range of unfettered homegrown talents. That range is remarkable, as I say⎯vineyards of every terroir have produced stunning varietals⎯and demands exploration of its roots, its reasons. That’s where I’ll end, with the question of Why now?

Now, over on the Continent, this wouldn’t be news. Paris and Berlin reclaimed their place on the cutting edge following the last World War, and European fiction has sprouted all sorts of wild hairs, whether by Alain Robbe-Grillet in the 1950s or Jenny Erpenbeck this past decade. Other pertinent names would fill several pages in Oulipo format, with paste-ins and marginalia, and the emotional range would run from the sourpuss Thomas Bernhard to the upwardly striving Bernardine Evaristo.

Naturally, more straightforward narrative has seen its champions as well. The latest is Elena Ferrante, with her Marxist economics and family sorrows. If any Italian since Dante can match that woman’s stature, however, it’s Italo Calvino, so radical an imagination that his Invisible Cities (1972) invented a fresh form for the novel. Reframing narrative, as Cities did, may provide the best handle on the recent European contribution to the artform. Other primary shape-shifters would include Beckett and Sebald.

The effort to construct a nouveau roman also energizes a good deal of the fiction out of the former European colonies. Again, the list could go on and on, but consider that India gave us the protean Salman Rushdie, Central Africa Alain Mabanckou, with his shaggy supernatural tales, and Oman (formerly a British “protectorate”) the Booker-winner Jokha Alharthi. Her novels are garnished with original poetry and hopscotch across a century of women’s lives.

For an American, it would seem only natural to venture something similar: to risk, at least once in a while, getting lost in the funhouse. I’m citing John Barth, of course, his watershed innovation from 1967, and among more recent US novelists, at least one went out of his way to pay that story homage. David Foster Wallace, rather a turn-of-the-millennium rock star, made free use of Barth’s Funhouse , the book as well as its title piece, in his ’89 novella “Westward the Course of Empire Takes its Way.” DFW’s story bogs down badly, it must be said, but the set in which it appears, Girl With Curious Hair, includes one or two of his most dazzling, and these reference previous experiments other than Barth’s. Throughout his too-brief career, this author honored his elders, the writers generally known as “the Postmoderns.”

Yet even as he brought off his own provocative spec-fic, Wallace took care to set it apart from the work of these same predecessors. In interviews he worried that novels and stories like Barth’s could be “enervating,” especially in their tendency to self-commentary, or meta-fiction. Misgivings like that come with the territory, part of any artist’s response to another, but what Wallace had to say was angrily amplified by his colleague Jonathan Franzen. The author of The Corrections has always subscribed to a more accessible model for fiction, and he defended it at length in a 2002 New Yorker essay, “Mr. Difficult”⎯otherwise an unforgiving takedown of William Gaddis, perhaps the greatest of the Postmoderns.

Franzen’s complaints were far from the first. Attacks on the freaks of US fiction go back to their freaky heyday, what you could call the Postmodern moment. This lasted about five years, roughly the first half of the 1970s, and the rock star of the group was Donald Barthelme. If New Yorker norms were sabotaged, Barthelme was the culprit, and he drew major media attention while sharing a girlfriend with Miles Davis (see the biography Hiding Man ). During those same years, too, Barth, Pynchon, and Gaddis each took home a National Book Award. But as they enjoyed the limelight, others sat grumbling in the dark.

An early reprisal came from Gore Vidal, who in “American Plastic” (1976) wielded his usual viper’s tongue. As for an argument, that was largely absent, but then John Gardner’s On Moral Fiction (1980) had even less to say, while serving up more vitriol. This book got some traction⎯Gardner, like Vidal, could write powerfully⎯but it’s little more than an executioner’s roll call: the Righteous and the Damned. The latter included even Gardner’s friend William Gass, sent to the block for seeking fictional alternatives.

To be sure, Gass and the rest of the condemned had their defenders; these days, Barthelme’s in the Library of America. Nevertheless, the beat-down went on for decades; first Tom Wolfe grabbed a cudgel (“The Billion-Footed Beast,” ’89), then Franzen. The attacks came with such regularity, and sounded so similar, it’s hard not to think of Puritanism, its lingering chill. The ripple effect was withering; the lascivious biplay of Robert Coover’s “The Babysitter” (1968), for instance, would get bumped off the syllabus or out of the anthology, while there was always space for the bleak monosyllables of Raymond Carver’s “What We Talk About When We Talk about Love” (‘81).

Surely an argument can be made for both sorts of stories, but in the US this was largely lacking until 2008, when Zadie Smith published her splendid and clarifying essay, “Two Paths for the Novel.” Still, even now, the more crooked and crazy path may be marked CLOSED. In recent weeks, I’ve heard a talented and well-published writer claim that, in the offices of Manhattan publishing, “anything experimental” will get “combed out” of a manuscript. I’ve read the sensitive critic Ron Charles, in his review of Jennifer Egan’s The Candy House , disdainful about her playfulness: “A second-person narrator? You shouldn’t have.” Recently I’ve witnessed the recent Twitterstorm, the thunder rumbling on both sides of the issue, after journalist Ben Judah called for, well, moral fiction: for “the great society novels” of the past, “the Zolas, Balzacs, Austens, Tolstoys….”

Whether prompted by our grim-faced forefathers or the smirking Gore Vidal, the US critical establishment developed a discomfort with the label “Postmodern.” These days, a text like Gaddis’ JR (1975) might instead be called a “systems novel.” The systems in question are the larger controlling forces of our lives, and certainly JR makes a good example; it turns us all to hamsters on the wheel of Big Finance. Still, this handle too proves slippery. I first encountered the expression in Tom LeClair’s work on DeLillo ( In the Loop , 1988), and in Libra (’88) or Underworld (’97), doesn’t “the system” carry guns? CIA, FBI, Mafia?

More recently, the NYTBR review of Whitehead’s Harlem Shuffle (2022) called it a systems novel, and in Whitehead’s imagination, it’s race that holds the reins. The Prime Mover, the source of our troubles, provides a central subject of any good drama, after all. That includes social realism like Ferrante’s. What’s more, to insist that a single purpose unifies all the new American efforts to bend and fold the fictional form⎯doesn’t that violate the very project?

DeLillo’s case tells us something, since he wears the dual descriptors of Postmodern and systems novelist. Critical consensus holds that the man’s peak came a while back, with the brilliant run from Libra to Underworld , while the 21st-Century work is regarded, by and large, as a letdown. Michiko Kakutani of the Times gave Falling Man (2007) her Imperial thumbs-down, declaring it “spindly” and “inadequate.” Even DeLillo himself, when he relents to an interview, will admit he’s no longer writing the way he used to. Beyond that, to be sure, the man remains cagey, and yet any objective comparison between his latest half-dozen and their honored predecessors at once reveals the salient difference.

The work since Body Artist (‘01) is more experimental . Their materials tend to the surreal; Zero K (’16) even tosses in a voice from the dead⎯or is it the undead? Their central action tends to totter off-center, and as for “systems,” most of the protagonists drift at a level of comfort that leaves the question moot. The author has left the ballpark, the sweat and grit so essential to Mao II (1991) and “Pafko at the Wall.” Instead, he’s going for shadow, suggestion, myth. Whether that makes for great fiction is another question, to be sure, but if you ask me, whichever muse inspired Cosmopolis, (‘03) she’s a magical seductress. I’d call that one a fable of renunciation: the Emperor strips off his own clothes.

Insofar as DeLillo belongs in any New Wave, though, he’s its gnomic Elder. Among the younger and more approachable are writers like Laura van den Berg and Amber Sparks. Again, these two are but a small sample; forerunners include Aimee Bender, who’s spent a quarter-century reinventing the fairy tale; newer on the scene would be Missouri Williams. Her debut The Doloriad (a title that recalls Barth) presents a post-apocalyptic society to make your hair stand on end⎯as do some of the imagined futures in Sparks and van den Berg. Find Me (2015) , van den Berg’s first novel, takes place in a US devastated by a memory-destroying plague. “The Men and Women Like Him,” from Sparks’ 2016 collection The Unfinished World , depicts the unexpected agonies of a civilization that’s figured out time-travel.

Of the two, Sparks is the more ostensibly out there. Her three collections are full of specters, witches, and old gods reborn. She makes mischief with form and language, too; stories sprawl “like some strange, bloody, chaotic plant,” and several wouldn’t look out of place in an Escher exhibit. Yet if Sparks is playing tricks, the joke’s on us. Her fictions are animated by a prickly social consciousness, one you sense in the very title of her splendid latest, And I Do Not Forgive You (2020). One of that book’s best, “Everyone’s a Winner at Meadow Park,” may be a ghost story, but its howls are those of the downtrodden.

As for van den Berg, her materials are more down to earth, but nonetheless spooky. In her 2018 novel The Third Hotel , a recent widow winds up seducing her husband’s ghost⎯in Cuba, where she’s gone on dubious pretenses. In “Karolina,” from her 2020 collection I Hold a Wolf by the Ears , the ghost confronting another solo voyager is estranged family, half-crazy yet something of a Cassandra. Van den Berg sets all her women eerily adrift; even a dreary apartment complex can seem “a kind of purgatory where we docked until our souls were called elsewhere.”

And as in Sparks, these elements feel feminist: a demonstration of how quickly and callously women can be stripped of care and support. The resulting riddle of identity, van den Berg’s abiding conundrum, finds vital expression in wild verb coinages. A woman doesn’t just sigh over how close she and her friends used to be; “We wept secrets,” she mourns. “We eavesdropped nightmares.”

The displacement that haunts these young women feels very 21st-century. It’s the uneasiness of the refugee, really, a defining trauma for our time, and widespread in this country. On America’s margins, hardscrabble cultures express their turmoil in all sorts of novels and stories, and some of the best-known are the most unconventional. Viet Thanh Nguyen fled Vietnam as a child, and his violent, comedic refashioning of his bicultural experience, in The Sympathizer (2015), won the Pulitzer. The Cherokee writer Brandon Hobson has clearly studied Louise Erdrich’s crazy quilts of Lakota culture; his The Removed (2021) includes whole chapters of dissociative nightmare.

The dread has seeped into mainstream cultures as well. The fictions of Sparks or van den Berg look like cases in point, but a more striking one would be Lance Olsen, plainly of Northern European extraction and raised, as he puts it in his memoir [[there]] (2014), in a “bland foliaged suburb” of New Jersey. Nevertheless, his fiction (as well as his mélange of a memoir) has focused more and more on men, women, and the occasional monster who’ve lost their bearings. Some are bushwhacked by fate, flailing but most likely done for, while a few others rush headlong towards self-destruction. In every case, though, the text in which they turn up looks outrageous.

“Experimental writing,” as most people conceive the term, suits Olsen’s work better than that of all the writers I’m discussing. Percival Everett might object, but even he would admit Olsen has birthed some mooncalves, his typography all over the place and even the books themselves, in a case like the double-sided Theories of Forgetting (2014), oddly configured.

Those two authors also share a breathtaking prolixity. I’ll be getting to Everett, and Olsen’s latest, Skin Elegies (2021), brings his bibliography to thirty titles, mostly novels. Lately, these have asserted a fresh power. The author’s recent saturation in European culture, in particular his sojourns in Berlin, has deepened his sensitivity to human precariousness. Nothing so gnaws at his people, in these teeming later fictions, as the awareness “that every meeting is / the origin of a leaving.” The quote is from a Fukushima survivor, in Skin Elegies , texting about her harrowing escape. The entire novel teeters on the verge of death, in Fukushima, on the doomed shuttle Challenger , in a Swiss euthanasia clinic, and elsewhere. Each setting has its own layout and style, too, from lines of text to stream of consciousness.

Collage also provides the form in Olsen’s previous, My Red Heaven (2020), though the elements of this composition are very different, in keeping with a very different narrative surrogate. Red Heaven takes place over a single day in Berlin, 1927, and visits with everyone from Goebbels and Hitler to Kafka’s late-life wife Dora (a Jew who escaped the Holocaust, the novel reminds us) and the obscure and struggling Walter Benjamin (a Jew who didn’t get out; the novel flashes forward to his suicide). These and many others are all caught in the evanescence, the superlunary glow just before an eclipse; all suffer the giddiness Benjamin jots down in 1927, sounding as if it’s already 1940 and he’s taken his fatal dose of pills: “ I’m falling in love with my lostness.”

Olsen may have more powerful novels⎯ Calendar of Regrets (2010), possibly. Nevertheless, My Red Heaven and Skin Elegies stand like twin peaks worthy of the David Lynch reference: story-substitutes no one else could’ve brought off, and yet in their shock, life-giving.

Colson Whitehead has delivered plenty of shocks as well, though his apparatus doesn’t look so abnormal. Regardless of how he ranks as a rulebreaker, though, Whitehead’s into a stretch as stunning as DeLillo’s in the ‘80s and ‘90s. Nickel Boys (2019) may have picked up more awards than Underground Railroad, I can’t keep track, and Harlem Shuffle has so far done splendidly. More pertinent for this essay is how the most recent novels tame the author’s wild streak.

Both books present the America we know all too well, where anyone born the wrong color contends with Sisyphean economics and due process, and both keep their chronology straightforward. Granted, the three linked sequences of Shuffle conceal a trompe l’œil or two, and Nickel Boys has a metafictional aspect, with its constant notetaking and rumor-sharing. Even shackles tell a story: “The iron is still there. Rusty. Deep…. Testifying.” Still, when I call Whitehead a champion of the New Eccentrics, I’m thinking primarily of the work that began with his debut The Intuitionist (’99)⎯no doubt the world’s only novel of mystic elevator repair⎯and culminated in The Underground Railroad.

The narrative of Whitehead’s masterpiece depends on an imaginative leap now known to any Goodreads user, but previously unseen outside of steampunk: an actual refugee railway deep in the earth. Whitehead’s invention does largely without nuts and bolts, too, it’s dreamy around the edges, so that the lone correlative I think of comes in Song of Solomon, with its climactic discovery that “the people could fly.”

Certainly, Toni Morrison presides like fertile Demeter over the contemporary efflorescence of Black literature, but Whitehead takes risks all his own. He’ll apply a refined rhetorical balance to inhuman abuse: “the travesties so routine and familiar that they were like weather, and the ones so imaginative in their monstrousness that the mind refused to accommodate them.” He’ll adopt perspectives as antiphonal as an escaped slave and a “slave catcher,” also putting each viewpoint though acute reversals. Stories so far apart yet so entwined come to embody a core insight: “truth was a changing display in a shop window, manipulated… when you weren’t looking.” If there’s anything that can resist that manipulation, it’s the supernatural journey underground: “the miracle beneath. The miracle you made with your own sweat and blood.”

I could go on pulling citations, but Whitehead’s accomplishment is best appreciated not in its parts but as a whole⎯a novel. This one had forerunners (one thinks also of Ellison’s Invisible Man ), but Underground Railroad offers such a ride, bruising and mind-blowing, it creates a fresh model for imagining the tormented history of race.

Among the texts that share the model, a signal case would be Sing, Unburied, Sing (2017). Jessamyn Ward’s unhappy family is unhappy in its own way, to be sure, and her story’s set largely in the present. I doubt any of the novel’s rave reviews termed it “experimental.” Nevertheless, in this case too, the Deep South is a place of ghosts, with many a wrinkle in time.

Yet while the same shadows fall across a number of recent texts, Whitehead’s historical revisionism is by no means the rule, in Black fiction these days. No neighborhood in America is monolithic, anymore, and this applies on the aesthetic fringes as well. Both Paul Beatty’s The Sellout (2015) and Rivers Solomon’s Sorrowland (2021) rival Underground Railroad for praise, but they upend expectation in very different ways. Both honor a different ancestor, the acerbic Ishmael Reed, whipping up horror and satire very much of the moment. When Beatty imagines a Black man calling for the reinstatement of slavery, or Solomon a bisexual teen mother who defends herself by turning into a monster, these wild developments bristle with insight. And for still greater diversity within this writing community, check out the lengthening shelf of titles from Percival Everett.

Novels make up the majority of his work, and altogether, they display a carnivalesque flexibility. Even when Everett observes Aristotelian unities, he knocks them out of whack. A few titles, however, rival the Postmoderns at their most radical, and one of those ranks among his most celebrated: Percival Everett by Virgil Russell (2013).

The novel’s all stories within stories, with new hybrids sprouting just as you’d got the hang of the last. Most are sprinkled with nonsense rhymes or literary allusions, and these yield, in turn, yet more stories. The sheer imagination compels the reading, that and the way each whirling prose dervish puts a fresh spin on our mortality. The dedication is to the author’s late father, and the novel opens on a father in assisted living, in halting conversation with his son. Even the more surreal images convey a chill: “We can fall asleep in a room full of the snoring dead.”

Near the end, a mathematical formula appears, and while I’ve no idea what it means, I do see that it features the infinity symbol, and that it brackets, at beginning and end, a brief, berserk chapter. This begins: “The real question was whether there was some real value to which all of this, all of our naming, thinking, speaking, breathing, wanting, loving, lusting….” The three pages that follow (and close with the math widget) are nothing but present participles: the linguistic formula which signifies life.

An alternative fiction without parallel, if you ask me, Percival Everett also prompted the actual Everett to yet another surprise. His followup, So Much Blue (2017), works with rhetoric and sequencing you might call commonplace. The recollections of an aging painter, its identities remain stable and its prose solid Strunk & White. While interactions can get extreme, they’re never impossible; people even speak between quotation marks. Yet the text juggles its narratives oddly, keeping secrets that any ordinary drama would have to let out of the bag, and the resolution has an unsettling ambivalence. Besides that, So Much Blue shares with its predecessor something crucial about the protagonists. The men are Black (the father too, in the earlier novel), but this doesn’t much matter. The character’s color is never germane to any of the plotlines.

Now, this author has by no means ignored the subject, over his career. In 2009, I Am Not Sidney Poitier had a nasty laugh at what white folks expect from Black literature, and his latest, The Trees , exacts bloody new revenge for the murder of Emmett Till. Overall, though, Everett’s fiction isn’t yoked to the torments of racism. Rather, his project keeps raising further questions, wanting, loving, lusting… experimenting.

Which leaves him in excellent company, nowadays. Busy company, at that: with each succeeding book season, Americans of all backgrounds and orientations are finding new ways to warp Freytag’s Triangle. Naturally, their gathering momentum by no means steamrolls over the sturdy old structures of character and catharsis, rising action and climax. Nor is the structures’ toolkit, with items like scrupulous observation and psychological acuity, in danger of rusting. So long as novels matter, there will always be a place for Edward P. Jones or Mary Gaitskill. By the same token, if the alternatives are enjoying a Renaissance, sooner or later it’ll confront its Savonarola, building bonfires of the vanities. Some of the writers I’ve praised might even take as bad a pasting as the Postmoderns.

That earlier backlash, from which the dust still hasn’t settled, does seem one of the prompts for the current eruption. Smart young writers aren’t oblivious to what their culture approves and forbids, and inevitably, the outcasts start to look intriguing. Then too, MFA workshops have grown notorious for how they rein in the high-kickers, insisting grimly on ”show don’t tell” and “less is more.”

Even Lan Samantha Chang, director at Iowa, has complained about the constraints. She’s mounted her own small rebellion, too, this year in The Family Chao . But all that’s mere literature, how it’s taught, read, and critiqued. Art remains a response to the whole world, not just its texts, and for any Stateside talent born since the Baby Boom, our world suffers a terrible need for new perceptions and configurations. A hundred years after “The Waste Land,” hasn’t the devastation grown worse? Isn’t the air full of ghost birds? Aren’t streets crowded with the displaced? Then why not⎯to cite other milestones from the same earlier ‘22⎯ dream up a new Ulysses , or “The Hunger Artist,” or À la recherche du temps perdu ?

To think in such terms, to set whole centuries in balance, takes you to the issue of ultimate value. You wonder where, on the scales of human storytelling, the needle might land for an Amber Sparks, a Paul Beatty. But that’s another question, though a perfectly good one. I mean, it’s still America. But this is still American fiction⎯that’s my point. This is our own witching hour, full of strange cries and peculiar apparitions, and that seems to me worth a drink. It’s not nothing to once more show the world that this artform just can’t be contained.

John Domini

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Paranoid explanations of experience: a novel experimental study

Affiliation.

1 Institute of Psychiatry, King's College London, UK. [email protected]
PMID: 20846468
DOI: 10.1017/S1352465810000457

Background: Paranoia is a common experience in the non-clinical population. We use a novel experimental methodology to investigate paranoid ideas in individuals without a history of mental illness.

Aims: We aimed to determine whether this paradigm could elicit unfounded paranoid thoughts and whether these thoughts could be predicted by factors from a cognitive model.

Method: Fifty-eight individuals took part and completed measures assessing trait paranoia, mood, self and other schema and attributional style. They were exposed to two experimental events: 1) an interruption to the testing session by a stooge, and 2) a recording of laughter played outside the testing room and subsequently asked about their explanations for these events.

Results: 15.5% (n = 9) of the sample gave a paranoid explanation for at least one of the experimental events. The remainder reported generally neutral explanations. Individuals with a paranoid explanation reported significantly higher levels of trait paranoia. Factors predictive of a paranoid interpretation were interpersonal sensitivity and attributional style.

Conclusions: The results show that spontaneous paranoid explanations can be elicited in non-clinical individuals, even for quite neutral events. In line with current theories, the findings suggest that emotional processes contribute to paranoid interpretations of events, although, as a novel study with a modest sample, it requires replication.

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Experimental Research Design — 6 mistakes you should never make!

Since school days’ students perform scientific experiments that provide results that define and prove the laws and theorems in science. These experiments are laid on a strong foundation of experimental research designs.

An experimental research design helps researchers execute their research objectives with more clarity and transparency.

In this article, we will not only discuss the key aspects of experimental research designs but also the issues to avoid and problems to resolve while designing your research study.

Table of Contents

What Is Experimental Research Design?

Experimental research design is a framework of protocols and procedures created to conduct experimental research with a scientific approach using two sets of variables. Herein, the first set of variables acts as a constant, used to measure the differences of the second set. The best example of experimental research methods is quantitative research .

Experimental research helps a researcher gather the necessary data for making better research decisions and determining the facts of a research study.

When Can a Researcher Conduct Experimental Research?

A researcher can conduct experimental research in the following situations —

When time is an important factor in establishing a relationship between the cause and effect.
When there is an invariable or never-changing behavior between the cause and effect.
Finally, when the researcher wishes to understand the importance of the cause and effect.

Importance of Experimental Research Design

To publish significant results, choosing a quality research design forms the foundation to build the research study. Moreover, effective research design helps establish quality decision-making procedures, structures the research to lead to easier data analysis, and addresses the main research question. Therefore, it is essential to cater undivided attention and time to create an experimental research design before beginning the practical experiment.

By creating a research design, a researcher is also giving oneself time to organize the research, set up relevant boundaries for the study, and increase the reliability of the results. Through all these efforts, one could also avoid inconclusive results. If any part of the research design is flawed, it will reflect on the quality of the results derived.

Types of Experimental Research Designs

Based on the methods used to collect data in experimental studies, the experimental research designs are of three primary types:

1. Pre-experimental Research Design

A research study could conduct pre-experimental research design when a group or many groups are under observation after implementing factors of cause and effect of the research. The pre-experimental design will help researchers understand whether further investigation is necessary for the groups under observation.

Pre-experimental research is of three types —

One-shot Case Study Research Design
One-group Pretest-posttest Research Design
Static-group Comparison

2. True Experimental Research Design

A true experimental research design relies on statistical analysis to prove or disprove a researcher’s hypothesis. It is one of the most accurate forms of research because it provides specific scientific evidence. Furthermore, out of all the types of experimental designs, only a true experimental design can establish a cause-effect relationship within a group. However, in a true experiment, a researcher must satisfy these three factors —

There is a control group that is not subjected to changes and an experimental group that will experience the changed variables
A variable that can be manipulated by the researcher
Random distribution of the variables

This type of experimental research is commonly observed in the physical sciences.

3. Quasi-experimental Research Design

The word “Quasi” means similarity. A quasi-experimental design is similar to a true experimental design. However, the difference between the two is the assignment of the control group. In this research design, an independent variable is manipulated, but the participants of a group are not randomly assigned. This type of research design is used in field settings where random assignment is either irrelevant or not required.

The classification of the research subjects, conditions, or groups determines the type of research design to be used.

Advantages of Experimental Research

Experimental research allows you to test your idea in a controlled environment before taking the research to clinical trials. Moreover, it provides the best method to test your theory because of the following advantages:

Researchers have firm control over variables to obtain results.
The subject does not impact the effectiveness of experimental research. Anyone can implement it for research purposes.
The results are specific.
Post results analysis, research findings from the same dataset can be repurposed for similar research ideas.
Researchers can identify the cause and effect of the hypothesis and further analyze this relationship to determine in-depth ideas.
Experimental research makes an ideal starting point. The collected data could be used as a foundation to build new research ideas for further studies.

6 Mistakes to Avoid While Designing Your Research

There is no order to this list, and any one of these issues can seriously compromise the quality of your research. You could refer to the list as a checklist of what to avoid while designing your research.

1. Invalid Theoretical Framework

Usually, researchers miss out on checking if their hypothesis is logical to be tested. If your research design does not have basic assumptions or postulates, then it is fundamentally flawed and you need to rework on your research framework.

2. Inadequate Literature Study

Without a comprehensive research literature review , it is difficult to identify and fill the knowledge and information gaps. Furthermore, you need to clearly state how your research will contribute to the research field, either by adding value to the pertinent literature or challenging previous findings and assumptions.

3. Insufficient or Incorrect Statistical Analysis

Statistical results are one of the most trusted scientific evidence. The ultimate goal of a research experiment is to gain valid and sustainable evidence. Therefore, incorrect statistical analysis could affect the quality of any quantitative research.

4. Undefined Research Problem

This is one of the most basic aspects of research design. The research problem statement must be clear and to do that, you must set the framework for the development of research questions that address the core problems.

5. Research Limitations

Every study has some type of limitations . You should anticipate and incorporate those limitations into your conclusion, as well as the basic research design. Include a statement in your manuscript about any perceived limitations, and how you considered them while designing your experiment and drawing the conclusion.

6. Ethical Implications

The most important yet less talked about topic is the ethical issue. Your research design must include ways to minimize any risk for your participants and also address the research problem or question at hand. If you cannot manage the ethical norms along with your research study, your research objectives and validity could be questioned.

Experimental Research Design Example

In an experimental design, a researcher gathers plant samples and then randomly assigns half the samples to photosynthesize in sunlight and the other half to be kept in a dark box without sunlight, while controlling all the other variables (nutrients, water, soil, etc.)

By comparing their outcomes in biochemical tests, the researcher can confirm that the changes in the plants were due to the sunlight and not the other variables.

Experimental research is often the final form of a study conducted in the research process which is considered to provide conclusive and specific results. But it is not meant for every research. It involves a lot of resources, time, and money and is not easy to conduct, unless a foundation of research is built. Yet it is widely used in research institutes and commercial industries, for its most conclusive results in the scientific approach.

Have you worked on research designs? How was your experience creating an experimental design? What difficulties did you face? Do write to us or comment below and share your insights on experimental research designs!

Frequently Asked Questions

Randomization is important in an experimental research because it ensures unbiased results of the experiment. It also measures the cause-effect relationship on a particular group of interest.

Experimental research design lay the foundation of a research and structures the research to establish quality decision making process.

There are 3 types of experimental research designs. These are pre-experimental research design, true experimental research design, and quasi experimental research design.

The difference between an experimental and a quasi-experimental design are: 1. The assignment of the control group in quasi experimental research is non-random, unlike true experimental design, which is randomly assigned. 2. Experimental research group always has a control group; on the other hand, it may not be always present in quasi experimental research.

Experimental research establishes a cause-effect relationship by testing a theory or hypothesis using experimental groups or control variables. In contrast, descriptive research describes a study or a topic by defining the variables under it and answering the questions related to the same.

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3-in-1 Blood Pressure Pill Could Be Treatment Advance

Key Takeaways

A new three-in-one pill is effective at controlling blood pressure

The pill outperformed standard care, which involves adding on individual drugs as needed

The pill has been submitted to the FDA for approval

WEDNESDAY, Sept. 4, 2024 (HealthDay News) -- An experimental three-in-one blood pressure pill works better than layering on meds one at a time, a new clinical trial shows.

After a month on the combo pill, 81% of patients had their blood pressure under control compared with 55% of patients receiving standard care, researchers report.

“The triple pill still produced clinically meaningful reductions in blood pressure compared to standard care, even when standard care closely followed current guidelines and involved more clinic visits,” said lead investigator Dr. Dike Ojji , head of the Cardiovascular Research Unit at the University of Abuja in Nigeria.

“In low-income countries, fewer than one in four treated people achieve blood pressure control, and in high-income settings it is only between 50% and 70%, so to see rates of over 80% in just one month is impressive,” Ojji added.

The GMRx2 pill, which was developed by the pharmaceutical company George Medicines, contains the blood pressure meds telmisartan , amlodipine and indapamide . It’s taken once daily. The company is part of the George Institute for Global Health .

Researchers compared people taking the combo pill to those receiving standard treatment for high blood pressure, which involves starting off with one drug and then adding on others.

Systolic blood pressure was 31 points lower in the combo pill group after six months of treatment, compared to 26 points lower with standard care, results showed.

The five-point systolic difference is equal to a 10% reduction in stroke, heart attack and heart failure risk between the two groups, researchers said in a George Institute news release.

It’s estimated more than a billion people worldwide have high blood pressure, which accounts for nearly 11 million deaths each year, researchers said in background notes.

George Medicines has submitted the combo drug to the U.S. Food and Drug Administration for approval.

The trial results were presented Saturday at the European Society of Cardiology’s annual meeting in London and published simultaneously in the Journal of the American Medical Association . Positive data from two other trials of the combo pill were also presented at the meeting.

More information

The American Heart Association has more on managing high blood pressure .

SOURCE: George Institute for Global Health, news release, Aug. 31, 2024

What This Means For You

A new combo pill could help control blood pressure more effectively by delivering three meds at once.

Modeling of EDM parameter with novel W/O nano-emulsion

Technical Paper
Published: 02 September 2024
Volume 46 , article number 584 , ( 2024 )

Cite this article

Nikhil Jain ORCID: orcid.org/0000-0002-6245-3967 1 ,
Jinesh Kumar Jain 1 &
Deepak Rajendra Unune 2

This study investigates the potential of a novel water-in-oil nano-emulsion (W/O) synthesized from non-edible refined jatropha oil as a dielectric fluid to enhance the electric discharge machining (EDM) process. W/O nano-emulsion was synthesized in two different surfactant concentrations, namely 10% and 15%. Influence of different input parameters, including current, pulse-on time, pulse-off time, and the concentration of the dielectric fluid, was explored on the key output responses, namely the material removal rate (MRR) and surface roughness. After evaluating its dielectric properties and observing a smaller particle size (46.33 nm) with a polydispersity index of 0.103, the 15% surfactant concentration was selected for EDM testing in comparison with conventional EDM oil. A mathematical model was developed using a face-centered cubic design model of the response surface methodology, and the results were subsequently compared with those obtained from an artificial neural network (ANN) model. The quadratic mathematical model for both MRR and surface roughness closely aligned with the experimental data, with current identified as the most influential parameter affecting both MRR and surface roughness. Pulse-off time, on the other hand, exhibited minimal impact on EDM performance. Furthermore, error analysis was conducted to compare the accuracy of the RSM and ANN models, with the ANN model demonstrating the least error. Notably, the machined surface exhibited fewer cracks and pores in the presence of the proposed (W/O) emulsion and displayed improved micro-hardness compared to conventional EDM oil.

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Machining performance and sustainability analysis of PMEDM process using green dielectric fluid

Machining performance enhancement of powder mixed electric discharge machining using Green dielectric fluid

Mathematical modeling and experimental evaluation of superalloy EDM using cryogenically treated electrodes and transformer oil-based dielectrics: a correlation study

Data availability.

The data have been derived from the experimental observation, and no data are incorporated from any other source.

Abbreviations

Material removal rate

Surface roughness

Water-in-oil nano-emulsion

Electric discharge machining

Scanning electron microscopy

Analysis of variance

Artificial neural network

Response surface methodology

Levenberg–Marquardt

Bayesian regularization

Scaled conjugate gradient

Resilient propagation

Broyden, Fletcher, Goldfarb, and Shanno

Center composite design

Mean square error

Recast layer thickness

Peak current

pulse-on time

pulse-off time

Correlation coefficients

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Department of Mechanical Engineering, Malaviya National Institute of Technology, Jaipur, 302017, India

Nikhil Jain & Jinesh Kumar Jain

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Conceptualization and Writing were done by Nikhil Jain; Editing and Supervision were done by Dr Jinesh Kumar Jain and Dr Deepak Rajendra Unune; Data Collection and Analysis were done by Nikhil Jain and Dr Deepak Rajendra Unune.

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Jain, N., Jain, J.K. & Unune, D.R. Modeling of EDM parameter with novel W/O nano-emulsion. J Braz. Soc. Mech. Sci. Eng. 46 , 584 (2024). https://doi.org/10.1007/s40430-024-05160-x

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Published: 04 September 2024

A comprehensive study on Mecanum wheel-based mobility and suspension solutions for intelligent nursing wheelchairs

Zhang Zhewen 1 ,
Yu Hongliu 1 ,
Wu Chengjia 1 ,
Huang Pu 1 &
Wu Jiangui 1

Scientific Reports volume 14 , Article number: 20644 ( 2024 ) Cite this article

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Engineering
Health occupations

Intelligent nursing wheelchairs significantly enhance mobility and independence for elderly individuals with disabilities. However, traditional designs often suffer from large turning radii that restrict their functionality in confined spaces. Addressing this critical challenge, this study introduces an innovative design utilizing a Mecanum wheel chassis that allows for omnidirectional movement, significantly improving maneuverability and stability. Our design incorporates independently controlled Mecanum wheels, overcoming traditional constraints and enhancing user autonomy. To address issues such as wheel spacing variations and hub center tilting, which can lead to slipping and inaccurate motion control, we developed a novel suspension system that stabilizes the chassis, minimizes slipping risks, and boosts motion control accuracy. Experimental validations, including shock absorption and positioning tests, demonstrate that our suspension system markedly enhances the wheelchair's control performance and stability, thereby providing users with enhanced precision and potentially improving their quality of life.

Introduction

In the past few decades, it has been observed that the health issues faced by elderly individuals in long-term care have become increasingly complex 1 . Elderly individuals typically suffer from multiple diseases simultaneously 2 , leading to the need for assistance in various daily activities, particularly in walking and transferring 3 , 4 . As a crucial assistive device in the field of rehabilitation, smart wheelchairs not only provide self-care independence for elderly individuals with mobility challenges but also enhance their quality of life. According to the World Health Organization, the effective integration of innovative technologies in wheelchairs is essential for enhancing the mobility and autonomy of disabled individuals 5 , 6 . With the escalating global aging population issue, the demand for nursing wheelchairs is gradually rising 7 , 8 , 9 . Although nursing wheelchairs play a pivotal role in providing mobility and rehabilitation support, their maneuverability and positioning capabilities have been a key challenge 10 . Traditional nursing wheelchairs typically employ rear-wheel or front-wheel drive systems 11 , 12 , limiting their maneuverability and requiring larger turning radii. This restricts the usage of nursing wheelchairs in confined environments such as hospitals, nursing homes, and households. Users often face difficulties in operating the wheelchair in narrow spaces, especially when quick turns or navigating through complex obstacles are required 13 , 14 . To further illustrate the advantages of Mecanum wheelchairs over traditional differential drive wheelchairs, it is essential to highlight the operational challenges posed by the latter. Differential drive wheelchairs, which rely on varying wheel speeds for steering and navigation, often require frequent repositioning to adjust the gap between the wheelchair and another surface, such as a bed or sofa, to ensure safe transfers. This frequent adjustment can be cumbersome and physically demanding for users, particularly for the elderly who may lack the strength and agility to maneuver the wheelchair precisely. In contrast, the lateral movement capability of Mecanum wheelchairs simplifies this process. By enabling side-to-side movement without the need to rotate the chair, Mecanum wheelchairs reduce the need for repeated adjustments, allowing for smoother, more efficient side transfers and enhancing the user's independence and safety.

To address these issues, this study proposes a design of an Mecanum mobile chassis based on Mecanum wheels. By introducing four specially arranged Mecanum wheels, we achieved an Mecanum wheel mobile chassis design, enabling the nursing wheelchair to move freely in any direction and significantly enhancing its maneuverability. This innovative design allows the nursing wheelchair to easily navigate challenges in confined spaces. Despite the substantial improvement in maneuverability brought about by the Mecanum mobile chassis design, it also faces several technical challenges 15 , 16 . The unique construction of Mecanum wheels may lead to changes in wheelbase and tilting of the wheel hub center during movement, directly causing issues such as slipping and inaccurate motion control of the nursing wheelchair 17 . According to the fundamental principles of geometry, three points determine a plane. On uneven surfaces, a four-wheel Mecanum wheel mobile platform is prone to a situation where one wheel loses contact with the ground, further resulting in directional control failure.

In this context, this paper discusses the phenomenon of poor maneuverability of nursing wheelchairs in confined indoor environments and proposes corresponding solutions. The next section will provide a detailed introduction to the design of the Mecanum mobile chassis. The third section conducts a comprehensive theoretical analysis of the Mecanum mobile chassis's independent suspension based on its mechanical model and kinematic simulation. Following this, the fourth section systematically analyzes the control performance and positioning capabilities of the nursing wheelchair through experiments involving mobility, positioning, and vibration tests. The final section summarizes the research findings and presents recommendations for future work.

Mecanum mobility chassis design for nursing wheelchairs

The objective of this study is to address the limited maneuverability of traditional nursing wheelchairs in confined spaces, a prevalent issue due to their large turning radii. Traditional designs often fail to accommodate the maneuvering requirements essential for enhancing user independence in tight environments 18 . To overcome these challenges, this study proposes a Mecanum wheel mobile chassis design, equipped with four independently controlled Mecanum wheels, aimed at enabling unrestricted directional movement. Furthermore, an independent suspension system is introduced with the potential to stabilize the chassis and improve motion control, thereby aiming to reduce slippage risks and enhance control precision.

Suspension system design

Before delving into the design of the Mecanum wheel mobile chassis, it is essential to understand the characteristics of a mobile chassis composed of Mecanum wheels. As shown in Fig. 1 , a Mecanum wheel is constructed from several rollers arranged at a 45-degree angle, forming the wheel. This arrangement means that the frictional force f from the ground experienced by the Mecanum wheel during rolling is not parallel to the direction of travel but is at a 45-degree angle to it, as shown in Fig. 1 . For lateral movement, the four correspondingly installed Mecanum wheels must work together to move the chassis in the predetermined direction. This implies that during the movement, the hub shafts of the wheels must not become misaligned. Otherwise, it will lead to a deviation of the mobile chassis, known as Mecanum wheel drift.

Omni-directional mobile chassis moving structure.

Therefore, although the Mecanum wheel mobile chassis offers excellent maneuverability, the unique structure of the Mecanum wheels may lead to the following challenges during motion:

Instability in motion: The movement of Mecanum wheels may cause changes in wheelbase and tilting of the wheel hub center, potentially resulting in instability during the motion of the nursing wheelchair 19 .

Slippery risk: On uneven terrain or during turns, the instability of the wheels may lead to slippage during the wheelchair's motion 20 , consequently reducing the precision of wheelchair movement.

Vibration and jolting: Mecanum wheels consist of a special wheel rim and protruding rollers, indicating that collisions or asymmetric movements between wheels may result in the generation of vibrations and jolting 16 , 21 .

The small solid columns on the circumference of each omni-wheel have gaps, potentially introducing periodic vibrations to the mobile platform. These irregular movements may be transmitted to the chassis of the nursing wheelchair, causing vibrations and jolts. Historically, omni-wheel mobile platforms were commonly used in AGV (Automated Guided Vehicle) applications. To ensure stable operation, prior studies 22 , 23 proposed various suspension structures to maintain continuous contact between the four omni-wheels and the ground. However, these solutions are not applicable to nursing wheelchairs, such as the requirement mentioned later for the wheelchair to dock with a toilet. This necessitates a sufficiently large distance between the two Mecanum wheels.

To address the aforementioned issues, we propose a new type of suspension mechanism, as depicted in Fig. 2 . This independent suspension system features a fixed base in an L-shape. Its primary function is to serve not only as a secure attachment to the chassis frame but also as a guiding column within a guiding groove. The guiding column is confined to the guiding groove to ensure its vertical movement. Additionally, guiding bearings are installed at the gap between the L-shaped fixed base and the guiding groove, affixed to the L-shaped fixed base. The purpose of this design is to transform the relative movement between the fixed base and the guiding groove from sliding friction to rolling friction. This modification facilitates smoother relative movement between the chassis frame and the fixed Mecanum wheel along the guiding groove, enhancing the effectiveness of the shock-absorbing springs located between the guiding groove and the fixed base.

Independent suspension structure design. ( a ) mobIle chassis. ( b ) Independent suspension mechanism.

This design ensures that the jumping direction of the chassis frame and the omni-wheels remains vertically aligned, effectively addressing issues such as omni-wheel leaning and changes in wheelbase. By adjusting the tension of the shock-absorbing springs, the omni-wheels maintain constant pressure against the ground. This design helps prevent slippage issues that may arise when the nursing wheelchair traverses uneven terrain due to omni-wheels being suspended.

Omni-directional mobile chassis design

For the mobile chassis designed for nursing wheelchairs, as illustrated in Fig. 3 , to meet the requirement of docking with a toilet and assist patients in toileting, we integrated the drive motor and omni-wheels into a single unit. This integration aims to ensure that the distance T between the omni-wheels, placed in parallel, is sufficiently large, providing more space for the bottom of the nursing wheelchair to accommodate different toilet configurations.

Dimensional parameters of the mobile chassis for Mecanum wheel movement.

Additionally, each omni-wheel is equipped with an independent suspension system, restricting the freedom of movement in other directions, The structural parameters of the mobile chassis are shown in Table 1 . This design ensures that the jumping direction of the chassis frame and the omni-wheels remains vertically aligned, effectively addressing issues such as omni-wheel leaning and changes in wheelbase. By adjusting the tension of the shock-absorbing springs, the omni-wheels maintain constant pressure against the ground. This design helps prevent slippage issues that may arise when the nursing wheelchair traverses uneven terrain due to omni-wheels being suspended.

As a common tool for indoor nursing assistance, nursing wheelchairs are required to exhibit high maneuverability in confined spaces. To meet this demand, we employ a design featuring four Mecanum wheels, each installed at the corners of the nursing wheelchair's mobile chassis. The core of this design lies in the diagonal arrangement of the Mecanum wheels, enabling each wheel to rotate independently. By precisely controlling the speed and direction of each Mecanum wheel, the nursing wheelchair can achieve forward, backward, leftward, and rightward movements while accomplishing in-place rotations 24 . The diagonal arrangement of Mecanum wheels allows the wheelchair to effortlessly navigate narrow corridors, avoid obstacles, and even execute turns in extremely confined spaces, providing greater flexibility and convenience.

The mobile chassis mentioned in this paper is illustrated in Fig. 4 . To facilitate modifications and flexible adjustments of component positions, the framework of the mobile chassis is constructed using aluminum profiles, with Mecanum wheels equipped with independent suspension devices installed at each of the four corners.

Theoretical analysis

This chapter provides a mechanical model for the suspension system. By establishing an equivalent model of the suspension system, the force analysis under different conditions is examined, offering a theoretical foundation for subsequent experimental validations.

Mechanical model analysis of the suspension system

In designing our Mecanum wheel suspension system, we start by considering user-centric factors, such as the average weight of the users, which critically influence the selection of springs and the required stiffness and damping properties. This ensures the suspension system provides both comfort and stability. To further refine our design, we conduct a theoretical analysis focusing on how the user's weight is distributed across each Mecanum wheel. Each suspension component is designed independently, enabling detailed analysis of force on each wheel. This method allows us to accurately assess the impact of these forces on the entire mobile chassis, ensuring the system is optimized for real-world usage.

Each suspension unit operates independently, and its equivalent force diagram is shown in Fig. 5 . ${F}_{i}$ represents the reaction force of the ground under different loads, ${G}_{i}$ represents the force of gravity averaged over each suspension, ${f}_{i}$ represents the tension force applied to the shock-absorbing spring, ${H}_{i}$ represents the height of the ground under different loads, and $L$ is the length of the spring. Assuming the rolling friction coefficient of the Mecanum wheel is $\mu $ , the elastic modulus of the shock-absorbing spring is $E$ , and the standard height of the wheelchair chassis is ${H}_{s}$ 。

Independent suspension force modeling.

When the system is in equilibrium, the relationship between ${H}_{i}$ and ${G}_{i}$ can be expressed as follows:

The suspension system is installed at the four corners of the mobile chassis, aiming to ensure that each omni-wheel generates effective friction with the ground. On surfaces of varying smoothness, each omni-wheel applies positive pressure to the ground, effectively addressing the issue of drift in the entire mobile chassis when one omni-wheel spins freely. This, in turn, enhances positioning accuracy.

In the design of the suspension system, the selection of shock absorber spring stiffness and initial deformation is crucial. The choice of these two factors directly determines the magnitude of the contact force between the Mecanum wheel and the ground. Appropriately selected shock absorber springs determine the stability of the chassis and the traction of the Mecanum wheel. This study focuses on the indoor mobility of a nursing wheelchair. As the shown in Table 2 , for the indoor motion process, three common indoor floor smoothness levels are considered for the force analysis of the suspension system.

We analyzed the stress on the suspension under different roadside conditions, as shown in Fig. 6 . On different levels of ground smoothness, to prevent the occurrence of wheel slip in Mecanum wheels, it is essential to ensure that each independent Mecanum wheel generates sufficient positive pressure on the ground.

Model forces under ground with different flatness.

When analyzing the forces on the shock absorber springs, the minimum positive pressure on the Mecanum wheels should be considered. Therefore, when installing the shock absorber springs, a pre-tension force $F$ needs to be set. Considering the range of different indoor ground smoothness, it is found that in environments with deep grooves, the pre-tension force ${f}_{2}$ on the spring is minimized. At this point, the pre-tension force of the shock absorber spring should be:

The formula above shows that the chassis height ${H}_{i}$ is related to the load ${G}_{i}$ and the elastic modulus $E$ of the shock absorber spring. When selecting the spring, it should be chosen based on the standard height ${H}_{s}$ of the wheelchair chassis according to the national standard, and the selection of spring material should be made in consideration of the minimum pre-tension force ${f}_{2}$ of the spring.

Suspension simulation analysis

The nursing wheelchair, as a crucial caregiving tool in rehabilitation equipment, should also consider its applicability in design 25 . The nursing wheelchair mentioned in this paper is designed for indoor environments. Therefore, in the simulation analysis, various degrees of uneven ground surfaces were simulated, and the changes in the center of mass of the mobile chassis and the four Mecanum wheels were recorded. The primary objective of our simulations was to evaluate the damping effects of the suspension system on the mobile chassis across various surface conditions. The most direct indicator of the suspension's performance is the z-axis displacement, which vividly demonstrates the system's ability to absorb shocks. To minimize variables and maintain consistency throughout the simulations, the mobile chassis was set to move at a constant speed of 0.5 m/s for simulation testing. This controlled setting allows us to isolate the impact of the suspension system on reducing vibrations and enhancing stability across different terrains. Additionally, one reason for choosing this lower speed is to consider the practical needs in narrow indoor environments. In indoor settings, wheelchairs frequently need to adjust their positions to accommodate narrow or crowded spaces. Operating at higher speeds in such environments could increase bodily swaying during positional adjustments, potentially compromising user safety and comfort. Moreover, when the wheelchair transitions over surfaces of varying heights, higher speeds can also lead to user discomfort and instability, especially when traversing uneven ground. For our speed selection, we also referred to the speed settings in paper 26 , which similarly used a lower speed to simulate indoor usage, further supporting our choice.

The simulation in this study was conducted in ADAMS, as shown in Fig. 7 . Firstly, we established the simulation model for the mobile chassis in ADAMS, with a load of 100 kg on the mobile chassis. The road surface model was configured as shown in Table 3 . During the model setup, constraints were defined for each component, and the same rotational speed was applied to each wheel for simulation.

Modeling the mobile chassis in ADAMS.

In Fig. 8 , the simulation results demonstrate the capability of the mobile chassis equipped with an independent suspension system as it navigates through various surface conditions, specifically depressed and raised surfaces. Initially, the simulation explores two depths of surface depressions—2.5 mm and 5 mm. It reveals that while the Mecanum wheels’ center of mass undergoes vertical displacement nearly equivalent to these depths, the overall chassis' center of mass experiences a less pronounced shift, roughly half the depth of the depressions. This outcome results from the load redistribution among the wheels, where the ones not entering the depression compensate by bearing most of the suspension's weight, thus adjusting the overall balance and maintaining stability.

Variation of center of mass of mobile chassis and McNamee's wheel for different flatness ground environments.

Subsequently, the simulation assesses the chassis performance over raised surfaces of 2.5 mm and 5 mm heights. Each wheel that encounters a bump reflects a center of mass shift proportional to the bump's height, yet the integrated action of the independent suspension system ensures that the overall center of mass of the suspension remains stable. This minimal shift in the total center of mass despite individual variations underscores the suspension system’s effectiveness in dampening impacts and maintaining the stability of the chassis on uneven terrains.

The simulation tests were specifically designed with surfaces featuring extreme height differences to rigorously evaluate the independent suspension system's damping capabilities. These results confirm the system's significant role in reducing the damping effects on the chassis across surfaces with marked roughness. This approach highlights the suspension system's effectiveness in maintaining performance under severe conditions, ensuring the wheelchair's ability to navigate effectively over rough and uneven terrains encountered in various environments. The focus on these extreme conditions underscores the robustness of the suspension system in enhancing the wheelchair's operational reliability.

Experimentation and analysis

The objective of this section is to validate the performance of the wheelchair in indoor navigation scenarios. This involved conducting systematic tests on the wheelchair's linear and rotational movements, as well as its navigation across various surface materials. The experimental outcomes were subsequently subjected to detailed analysis.

Linear motion positioning tests

First, we conducted repeatability tests on the wheelchair's straight-line movement performance on a marble surface. Motion commands were pre-programmed into the motor control system to facilitate linear movement. The testing scenario and the wheelchair setup are illustrated in the accompanying Fig. 9 .

Test environment and equipment. ( a ) Marble floor and IMU. ( b ) The nursing wheelchair.

The wheelchair was tested over lateral and straight-line distances of 5 m, 10 m, and 15 m. During the tests, the starting point of the wheelchair was consistently maintained for each type of movement, and deviations between the actual and ideal endpoints of each run were recorded. To ensure the reliability of the data, each type of movement for each distance was tested five times.

The results of these tests are shown in Fig. 10 : for straight-line movements, the maximum error of the wheelchair when traveling a distance of 5 m is 1.5 cm, and for lateral movements, the maximum error is slightly higher at 2 cm. With the increase in travel distance, the maximum errors for the wheelchair traveling 5 m and 10 m in straight-line are 5 cm and 6.9 cm, respectively, while for lateral movements, the errors are 6 cm and 8.1 cm, respectively. From the experimental results, we observed that although deviations in the traveled distance do exist, they are considered negligible given the objectives of our experiments and the anticipated usage environment of the wheelchair. Our tests primarily focus on the influence of the wheelchair's structural design on positioning during short-distance maneuvers, defined here as movements within 5 m. Such distances typically encompass typical usage scenarios within indoor environments, such as transitions from one room to another or docking maneuvers between a wheelchair and a bed chair. In these short-range movements, even slight path deviations do not significantly impact the operational performance of the wheelchair or user safety.

Measurement errors for different distances traveled by nursing wheelchairs.

Positioning and vibration tests in mixed motion modes under different loads

To investigate the phenomenon of slippage in nursing wheelchairs, we conducted experiments on the wheelchair's lateral movement, rotational motion, and straight-line motion, with a motion trajectory of a 3 m × 3 m square, as shown in Fig. 11 . The experiment was conducted on a commonly found indoor marble surface. The testing speed was 1.0 m/s. We used a NOKOV camera device to capture the wheelchair's trajectory throughout the entire motion process and recorded it.

Test the wheelchair movement trajectory with the NOKOV camera.

In preparation for the tests, we programmed the wheelchair with a simple trajectory algorithm to control the motors to move along the desired path, intentionally not incorporating any motion feedback sensors to control variables. Additionally, as a comparative validation, we conducted four tests. To ensure that the results were not influenced by other variables, the control program settings and the surface environment were kept consistent. Initially, to verify the impact of no load and load on the Mecanum wheel mobile chassis, we performed tests on the mobile chassis with a suspension system under no load and load conditions, respectively. Subsequently, as a comparison, we also tested the Mecanum wheel mobile chassis without a suspension system under both no load and loaded conditions, with the tests being conducted both unloaded and with a 100 kg load.

The test results, as shown in Fig. 12 , indicate that the wheelchair without a suspension system deviates significantly from the ideal trajectory during motion, especially during rotational movements. This deviation, which increases with the extent of rotation, is primarily attributed to the slippage of the Mecanum wheels during rotational motion. In contrast, the trajectory of the wheelchair equipped with a suspension system closely aligns with the theoretical path, demonstrating that the suspension system effectively prevents slippage of the Mecanum wheels on the moving chassis, thereby enhancing the positioning accuracy of the wheelchair.

Hybrid motion trajectory diagram.

Additionally, we observed differences in the motion of the wheelchair under loaded and unloaded conditions. A researcher was seated in both the suspended and non-suspended wheelchairs to record trajectory changes. The experimental results reveal that adding load to the non-suspended wheelchair still resulted in a significant deviation from the ideal trajectory, whereas the loaded wheelchair with suspension closely followed the theoretical path. We hypothesize that this occurs because, although adding direct load to a Mecanum wheelchair increases pressure, the uniformity of floor surface prevents the load from uniformly affecting each wheel. With the suspended wheelchair, the addition of load resulted in a trajectory closer to the theoretical path, likely due to the independent suspension's ability to effectively balance the pressure exerted on the Mecanum wheels. We plan to further investigate these hypotheses by testing a hybrid active–passive suspension system to validate these phenomena.

For wheelchair users, the addition of a suspension system to nursing wheelchairs helps reduce the impact and vibration experienced during travel, thereby lowering the potential for injury resulting from vibration 27 , 28 . Therefore, we recorded the vertical acceleration values of the wheelchair along the aforementioned test paths using an IMU installed on the wheelchair. We conducted tests on the wheelchair's straight-line motion, lateral motion, and rotational motion on a marble surface, as shown in Fig. 13 . The experimental results indicate that, under the effect of independent suspension, the damping effect of the nursing wheelchair is significantly increased compared to the situation without a suspension system.

Vibration testing of nursing wheelchairs, equipped with and without suspension devices, conducted on a marble surface.

Further analysis of the test data was conducted to compare the vibration conditions of wheelchairs with and without suspension systems under various motion patterns, employing the data processing method outlined in paper 29 . As shown in Fig. 14 , resulting graphs clearly demonstrate enhanced stability and comfort in wheelchairs equipped with suspension systems, across all tested motion patterns. The maximum RMS value during operation was 0.38 m/s 2 , significantly lower than the ISO 2631-1 standard 30 , 31 recommended comfort threshold of 1.6 m/s 2 . Similarly, the maximum VDV was 3.65 m/s 1.75 well within the comfort definition of less than 9.0 m/s 1.75 , These findings further validate the suspension system's efficacy in aligning with established standards for comfortable wheelchair seating.

RMS and VDV Values Across Different Modes of Motion.

Finally, we tested the wheelchair's performance on different surfaces. The test scenario, as shown in Fig. 15 , mainly consisted of a wool carpet and a leather carpet, joined by a transition strip that was 2.5 mm high and 25 mm wide, seamlessly integrating the two types of flooring. In this real-world scenario test, we set the wheelchair to operate at the same low speed of 0.5 m/s as used in the previous simulation environment. Similarly, to assess the impact of the independent suspension on the wheelchair's performance across different surfaces, we conducted tests on vibration conditions as well as comfort and stability analysis with and without suspension under the same 100 kg load.

Real-world testing scenarios.

In our experiments, as shown in Fig. 16 , we found that wheelchairs equipped with a suspension system demonstrated significant vibration damping effects on various ground conditions and when passing over obstacles. This suspension mechanism effectively absorbs and disperses the impact forces transmitted from the ground, thereby reducing the vibration impact on users. Furthermore, to better explain the stability and comfort of the wheelchair, we analyzed the vibration data for RMS and VDV values. The results, as shown in Fig. 17 , indicated that the maximum RMS value was 0.61 m/s 2 and the maximum VDV value was 5.56 m/s 1.75 , both of which are within the comfort range defined by ISO 2631-1 for wheelchair operation.

Vibration testing of wheelchairs with and without suspension systems on different road surfaces and surfaces with transition strips.

Analysis of the stability and comfort of the wheelchair on surfaces of varying roughness.

Conclusions

This study successfully developed a Mecanum wheel-based intelligent nursing wheelchair mobility chassis, significantly enhancing maneuverability in confined spaces through the introduction of an independent suspension system. Theoretical analysis and dynamic simulations revealed the effectiveness of the suspension system in improving the dynamic responses of the wheelchair and adapting to different road conditions. Experimental validation demonstrated that this suspension system effectively reduces vibration and slippage during movement, enhancing precision and safety in operation. Importantly, the design of the Mecanum wheels used in this study allows for lateral movement and on-the-spot rotation, greatly enhancing the wheelchair's flexibility in complex environments. Additionally, the experimental results confirm that the independent suspension system maintains stability and comfort under different loading conditions, further advancing the practical application of intelligent nursing wheelchair technology.

For future research, we plan to develop a hybrid active–passive control suspension system to explore the effects of drift during rotational movements of the Mecanum wheel mobility chassis. Through this hybrid control system, we aim to further optimize the dynamic performance and operational stability of the wheelchair, providing an effective technical solution to address potential drift issues caused by Mecanum wheels.

The findings of this study not only provide a new technical path for the design and manufacturing of nursing wheelchairs but also offer valuable insights for the future development of intelligent rehabilitation devices.

Data availability

All data generated or analysed during this study are included in this published article.

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This statement recognizes the support of the University of Shanghai for Science and Technology and mentions that the research was supported by the National Key R&D Program of China, under grant number 2022YFC3601400.

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Zhewen, Z., Hongliu, Y., Chengjia, W. et al. A comprehensive study on Mecanum wheel-based mobility and suspension solutions for intelligent nursing wheelchairs. Sci Rep 14 , 20644 (2024). https://doi.org/10.1038/s41598-024-71459-3

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Published: 04 September 2024

Eslicarbazepine induces apoptosis and cell cycle arrest in C6 glioma cells in vitro and suppresses tumor growth in an intracranial rat model

Nastaran Afsordeh 1 ,
Safura Pournajaf 1 ,
Hadi Bayat 2 ,
Fatemeh Mohajerani 3 ,
Amir Shojaei 1 ,
Javad Mirnajafi-Zadeh 1 &
Mohammad Hossein Pourgholami 1

BMC Cancer volume 24 , Article number: 1099 ( 2024 ) Cite this article

Metrics details

Glioblastoma multiforme (GBM) is the most malignant brain tumor, with a poor prognosis and life expectancy of 14–16 months after diagnosis. The standard treatment for GBM consists of surgery, radiotherapy, and chemotherapy with temozolomide. Most patients become resistant to treatment after some time, and the tumor recurs. Therefore, there is a need for new drugs to manage GBM. Eslicarbazepine (ESL) is a well-known antiepileptic drug belonging to the dibenzazepine group with anticancer potentials. In this study, for the first time, we evaluated the potential effects of ESL on C6 cell growth, both in vitro and in vivo, and examined its molecular effects.

To determine the effect of ESL on the c6 cell line, cell viability, proliferation, and migration were evaluated by MTT assay, colony formation, and wound healing assay. Also, apoptosis and cell cycle were examined by flow cytometry, qRT-PCR, and western blotting. In addition, an intracranial model in Wistar rats was used to investigate the effect of ESL in vivo, and the tumor size was measured using both Caliper and MRI.

The obtained results are extremely consistent and highly encouraging. C6 cell viability, proliferation, and migration were significantly suppressed in ESL-treated C6 cells ( p < 0.001), as determined by cell-based assays. ESL treatment led to significant enhancement of apoptosis ( p < 0.01), as determined by flow cytometry, and upregulation of genes involved in cell apoptosis, such as the Bax / Bcl2 ratio at RNA ( p < 0.05) and protein levels (5.37-fold). Flow cytometric analysis of ESL-treated cells revealed G2/M phase cell cycle arrest. ESL-treated cells demonstrated 2.49-fold upregulation of p21 alongside, 0.22-fold downregulation of cyclin B1, and 0.34-fold downregulation of cyclin-dependent kinase-1 at the protein level. Administration of ESL (30 mg/kg) to male rats bearing C6 intracranial tumors also suppressed the tumor volume and weight ( p < 0.01).

Conclusions

Based on these novel findings, ESL has the potential for further experimental and clinical studies in glioblastoma.

Graphical abstract

Peer Review reports

Gliomas are the most common type of adult brain tumor [ 1 ]. The World Health Organization (WHO) divides gliomas into four grades, and glioblastoma multiforme (GBM) fits into grade IV, which is the most malignant [ 2 , 3 ]. Despite concomitant Surgery, radiotherapy, and temozolomide (TMZ) chemotherapy as the first-line treatment for GBM [ 4 ], the prognosis is still poor, and average survival is approximately 14–16 months from the time of diagnosis [ 5 ]. Additionally, GBM is associated with various disturbing CNS symptoms [ 6 ], and factors depending on tumor location, the affected areas of the brain, and the disease duration may impact those disorders [ 7 , 8 ]. Defects in cognitive functions are common clinical symptoms of brain tumors (80%), which also occur in the in vivo GBM models in experimental animals [ 9 , 10 ]. Temporal lobe and entorhinal cortex tumors cause impairment in learning, memory, and attention processes and also induce seizures [ 11 , 12 ].

Due to the heterogeneous nature of GBM, chemoresistance is highly common among GBM patients, eventually leading to tumor recurrence [ 13 ]. Tumor recurrence and poor prognosis coupled with various drug-resistant symptoms make GBM a highly challenging disease that requires extensive investigations to identify new anticancer drugs to inhibit tumor growth and improve the management of patients.

Dibenzazepines are a well-known class of drugs that have been used for controlling epilepsy and mood disorders [ 14 , 15 ]. Up to now, three generations of this drug class have been introduced, including carbamazepine (CBZ), oxcarbazepine (OXC), and eslicarbazepine (ESL), as the first, second, and third generation, respectively [ 16 ]. The fewer side effects, higher safety, and efficacy of ESL led to its approval by the U.S. Food and Drug Administration (FDA) as a promising anticonvulsant treatment for epilepsy in 2013 [ 17 , 18 , 19 ]. ESL blocks voltage-gated sodium channels and decreases glutamate release [ 20 , 21 ]. Additionally, experimental studies have demonstrated the anticancer effectiveness of dibenzazepines in colon adenocarcinoma, HepG2 liver carcinoma cell lines [ 22 , 23 ], and even in a clinical trial of prostate cancer [ 24 ]. More interestingly, OXC has been shown to inhibit the proliferation of human GBM cell lines U87-MG and T98G under in vitro conditions [ 25 ].

Herein, we evaluated for the first time the anticancer effects of ESL on the rat GBM C6 cell line. The C6 rat model is considered the most relevant and the gold standard in experimental animal models for glioblastoma. Orthotropic C6 allografts provide considerable insights into the biological mechanisms of GBM progression and invasion as they reproduce in vivo characteristics of human gliomas, including genetic and growth patterns, and highly resemble the brain tissue micro-environment and its immune response. As a syngeneic model, the necessity for the use of immune-competent rats or the use of immunosuppressive drugs is avoided [ 26 ]. We conducted a step-by-step progressive series of tests, starting with cell proliferation, apoptosis, and the cell cycle evolution in vitro. The promising results led to an in vivo experiment in male rats bearing C6 intracranial tumors.

Materials and methods

C6 cells (ATCC Cat# CCL-107, RRID: CVCL_0194) were cultured in DMEM/F12 (GIBCO; Cat. #12500096) medium supplemented with 10% fetal bovine serum (FBS) (GIBCO; Cat. #A4736401) and 1% penicillin-streptomycin (GIBCO, Cat. #10378016) in a 37˚C and 5% CO 2 humidified incubator.

The 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide (MTT) (Sigma- Aldrich; Cat. #M2003) assay was used to assess the C6 cell’s viability. Cells (5 × 10 3 ) were seeded in 96-well microplates, left 24 h for attachment, and then exposed to different concentrations of ESL (0, 10, 25, 50, 75, 100,150, and 200 µM) for 48 and 72 h. Then, the cell media was discarded and replaced with 0.5 mg/ml MTT (Sigma- Aldrich; Cat. #M2003) stock solution. After 4 h, 100 ml dimethyl sulfoxide (Merck; Cat. #D8418) was added to each well and maintained for 15 min to dissolve formazan crystals. Finally, the absorbance of the samples was measured at 570 nm with a microplate reader (Cytation 3, United States).

Soft-agar colony formation assay

To perform a soft agar colony formation assay, DMEM-F12 containing 10% FBS, 1% pen strep/streptomycin, and 0.5% agar (BioBasic; Cat. #FB0010) was added to 6-well plates and rested at room temperature to solidify as the bottom layer. Next, C6 cells were suspended in DMEM F12 supplemented with 10% FBS, 1% pen strep/streptomycin, and 0.35% agar (BioBasic; Cat. #D0012), poured into each well as the top layer and cultivated in a humified incubator with 5% C0 2 . Wells were then treated with varying concentrations of ESL (0, 10, 25, and 50 µM) for 48 h. After 21 days, the cells were stained with a 0.1% filtered crystal violet (w/v). Formed colonies with more than 50 cells were counted using the ImageJ software (RRID: SCR_003070) [ 27 ].

To observe the impact of ESL treatment on C6 cell morphology, 1 $\:\times\:$ 10 4 cells were seeded in 6-well plates and incubated overnight for attachment, followed by treatment with ESL (0, 10, 25, and 50 µM) for 48 h. Cells were then fixed with 4% paraformaldehyde for 10 min and stained by Giemsa (Sigma-Aldrich; LOT# 0620) for 15 min. The images were captured by an inverted microscope (Olympus, BX51 TRF, USA) at 10× magnification.

Wound healing assay

In vitro cell migration was measured using a wound-healing assay [ 28 ]. C6 cells were seeded in 24-well plates (1 × 10 5 cells/well) and grown to 75% confluence. The plates were scratched using a sterile pipette tip and washed twice with PBS. Afterward, serum-free DMEM or ESL in different concentrations (0, 10, 25, and 50 µM) were added to each well. The wounded areas images were captured at indicated time points (0 and 24 h), and the scratch’s average width after cell migration was calculated using ImageJ.

Dual acridine orange/ethidium bromide (AO/EB) fluorescent staining

Apoptosis in C6 cells was assessed using AO/EB fluorescent staining (Sigma-Aldrich; MO) [ 22 ]. C6 cells (1 × 10 5 cells/well) were seeded in 6-well plates. After 24 h, the cells were treated with different concentrations of ESL (0, 10, 25, and 50 µM) for 48 h. Then, treated cells were washed with PBS, detached with Trypsin-EDTA 0.25%, and resuspended in phosphate-buffered saline 1X (PBS) buffer. Next, AO/EB (1 µl) was added to cell suspension (10 µL) and poured on a slide. The fluorescence intensity was monitored at 488 nm excitation using a fluorescent microscope (Olympus, BX-51 Japan). The percentage of apoptotic cells was determined using the ImageJ software.

Apoptosis and cell cycle analysis

The DNA content and cell cycle of C6 cells treated with ESL (25 µM) were analyzed using flow cytometry. For apoptosis analysis, 1 × 10 6 cells were stained with FITC-Annexin V and propidium iodide (PI) for 15 min in the dark at 24 and 48-htime points. For cell cycle analysis, 24 h after ESL treatment, 1 × 10 6 cells were fixed with 70% ethanol for 1 h and then incubated with PI for 30 min in the dark. The FACS Calibur Flow Cytometry System (RRID: SCR_000401) was used to measure cell cycle and apoptosis, and FlowJo v.10 software (RRID: SCR_008520) was used to analyze the results [ 29 ].

RNA extraction, cDNA synthesis, and quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR)

Total RNA extraction from C6 cells treated with 0 and 25 µM ESL for 48 h was performed using the Trizole reagent (DNAbiotech; cat. #DB9683) and DNase I RNase-Free treatment kit (AMINSAN; cat. #EADN01) according to the manufacturer’s instructions. First-strand cDNA was synthesized with 1 µg of total RNA from these cells using the Easy cDNA Synthesis Kit (Pars tous; cat. 751173).

Transcript levels of the candidate genes were measured by real-time PCR on ABI Step One Real-time PCR system (Applied Biosystems, United States, (RRID: SCR_014281)) using SYBR Green Real-Time PCR Master Mix (BioFact; Cat. #DQ385) reagent, with reaction cycling conditions as follows: 95 °C for 10 min (activation), 95 °C for 15s (denaturation), annealing for 30s at optimum temperature and 30s of extension at 72 °C. To quantify the expression of target genes, threshold cycles (Ct) were used by the 2 − ΔΔCt method with Beta-actin ( Actb ) as the internal reference gene. The primer sets used for Real-time qPCR analysis are listed in Table 1 .

Western blot analysis

To examine the effect of ESL (25 µM, 48 h treatment) on C6 cellular expression of BCL2, CDK1, BAX, CASP-3, CYCS, P53, CCNB1 and CDKN1A, western blot analysis was performed according to the standard procedure [ 30 ]. In Brief, following treatment and protein extraction from the cells, total protein was purified using ice-cold RIPA buffer (Cat. #9806; Cell Signaling Technology). The concentration of purified proteins was determined by Bradford assay. Whole-cell extracts were separated by SDS- polyacrylamide gel electrophoresis and transferred onto a polyvinylidene difluoride membrane (Millipore Corporation, MA, USA). The membranes were then incubated with specific primary and secondary antibodies as below:

The primary antibodies used : anti–ACTB (Santa Cruz Biotechnology; Cat# sc-517582), anti–BCL2 ( Santa Cruz Biotechnology; Cat. #sc-7382), anti-BAX ( Santa Cruz Biotechnology; Cat. #sc-7480), anti-CYCS ( Santa Cruz Biotechnology; Cat. #sc-13156), anti-CCNB1 (Santa Cruz Biotechnology; Cat. #sc-166210), and anti-CDKN1A ( Santa Cruz Biotechnology; Cat. #sc-6246), anti-P53 ( Santa Cruz Biotechnology; Cat. #ab131442) and anti-CDK1 ( Abcam; Cat. #ab131450), anti -CASP-3 (Cell Signaling; Cat. #14220), ( 1:1,000) ( Cell Signaling). Secondary antibodies: anti -mouse ( Santa Cruz Biotechnology; Cat# sc-516102 ) and anti-rabbit (Santa Cruz Biotechnology; Cat. #sc-2357) .

Immunoreactivity was visualized by Pierce ECL Western Blotting Substrate (Thermo Fisher Scientific; Cat. #32106) and photographed. Densitometry of the western blot was quantified using ImageJ software. β actin was used for equal protein loading.

Animal surgery and cell implantation

Twelve male Wistar rats weighing 200–250 g were purchased from the Pasteur Institute of Tehran and kept under 12 h of darkness and light in the animal house of Tarbiat Modares University (ethics approval code: IR. MODARES.REC.1400.101). The animals had ad libitum access to food and water. The rats were anesthetized with ketamine (90 mg/kg) and xylazine (10 mg/kg) and placed in a stereotactic apparatus to generate an intracranial C6 GBM model. Then, 10 6 C6 cells were injected into the right entorhinal cortex coordinated according to the Paxinos and Watson atlas as -8.0 mm posterior and 4.5 mm to the right of bregma and 4.1 mm below dura [ 26 ] by infusion pump. Animals were transferred to their home cage for recovery. Subjects were divided into the GBM + vehicle (VEH) group, in which animals received C6 cells and daily doses of the vehicle, and the GBM + ESL group, in which animals received C6 cells plus daily doses of ESL (30 mg/kg). Within 30 min after intracranial C6 injection, VEH or ESL was administered intraperitoneally twice daily for 18 consecutive days. At the end of the study, the tumor volumes were monitored by magnetic resonance imaging (MRI; T2 method, 3 Tesla, Voxel size = 0.2 × 0.2 × 0.8 mm3 and rat brain coil = 38 mm diameter); then measured by ITK software V3.8. Finally, the animals were sacrificed using ketamine/xylazine anesthesia. In compliance with the euthanasia recommendations stated in the “Guide for the Care and Use of Laboratory Animals”, and brain tumors were isolated. The weight and volume of the isolated brain tumors were calculated using a digital scale and caliper, respectively.

Statistical analysis

Data statistical analysis was performed using Graph Pad Prism (RRID: SCR_002798). One-way ANOVA and unpaired t-test followed by Tukey’s post-test were used when applicable to identify the differences between the studied groups. Data is presented as mean ± standard error of the mean (S.E.M.), with the statistical difference ( p < 0.05) considered at p < 0.05. Significance levels are denoted as * p < 0.05; ** p < 0.01; *** p < 0.001. All experiments were performed at least in two or three replicates.

ESL reduced cell viability, proliferation, and migration of C6 cells

To evaluate the effects of ESL (10, 25, 50, 75, 100, 150, and 200 µM) on cell viability, MTT assay was performed. Different concentrations of ESL significantly decrease cell viability compared to control cells (0 µM of ESL) at 48 h ( p < 0.001 vs. 0 µM: Fig. 1 A) and 72 h ( p < 0.001 vs. 0 µM: Fig. 1 B). The higher concentration of ESL showed enhanced suppression of cell viability. The IC 50 value was determined to find the lowest concentration of ESL for killing 50% of treated cells at 48 h (Fig. 1 C) and 72 h (Fig. 1 D), in which the log IC 50 was found to be 1.63 µM and 1.37 µM, respectively. We stained the treated cells (after 48 h under ESL treatment) to find out the effects of ESL (0, 10, 25, and 50 µM) on the morphology of the C6 cells. The obtained results were highly consistent with the MTT data in showing the concentration-dependent efficacy of ESL in profoundly suppressing cell viability and proliferation (Fig. 1 E).

Cell proliferation and colony formation are flagships of cancer cells. To evaluate the inhibitory effect of ESL on these two phenotypes, we performed a soft-agar colony formation assay with different concentrations of ESL (0, 10, 25, and 50 µM) over 21 days (Fig. 1 F). ESL significantly suppressed cell proliferation and colony formation of the C6 cells in three tested concentrations. The disruption was drug concentration-dependent, with a higher concentration of ESL having a significant positive correlation with decreased colony number (using a one-way ANOVA test) ( p < 0.001 vs. 0 µM: Fig. 1 G). Moreover, we carried out wound-healing assay to determine the effect of ESL on cell migration as a prominent feature of cancer invasion. According to our findings, ESL significantly suppressed gap closure compared to control cells (0 µM) after 48 h (Fig. 1 H). Increased concentration of ESL more significantly ( p < 0. 001) suppressed gap closure compared to vehicle (Fig. 1 I). Altogether, our results clearly demonstrate that ESL significantly reduced the cell viability, proliferation, colony formation, and migration of the C6 cells.

ESL suppressed cell viability, proliferation, colony formation, and migration of the C6 cells. MTT assay, using different concentrations of ESL (0-200 µM), was performed at 48 h ( A ) and 72 h ( B ). By increasing ESL concentration, the percentage of the viable C6 cells was significantly decreased at both time points ( p < 0.001). The IC 50 of ESL was 1.63 and 1.37 µM at 48 h ( C ) and 72 h ( D ), respectively. E ) Giemsa staining showed the morphology of the C6 cells under different concentrations of ESL (0. 25 and 50 µM). F & G ) Soft-agar colony formation assay showed an inverse correlation of colony number with ESL concentration. Increased concentration of ESL indicated a more significant reduction in colony formation of the C6 cells ( p < 0.001). H & I ) wound-healing assay demonstrated that the treated cells had significantly less migration at the higher concentration of ESL ( p < 0.001). Scale bar: 200 μm

ESL significantly increased apoptosis rate in C6-treated cells

To evaluate the effects of ESL on cell apoptosis, the C6 cells were treated with various concentrations of ESL (10, 25, and 50 µM) and stained by AO/EB. Compared to control cells (0 µM), ESL treatment led to increased apoptosis at 24 and 48 h (Fig. 2A). One-way ANOVA analysis showed that the percentage of apoptotic cells significantly increased in 25 ( p < 0.01) and 50 µM ( p < 0.001) treated cells at 24 h and in 25, and 50 µM ( p < 0.001) at 48 h (Fig. 2 B). To confirm our AO/EB staining, we evaluated the apoptosis rate of the treated C6 cells with 25 µM ESL, using Annexin V -FITC and PI staining and flow cytometry. The apoptosis rate of the treated cells significantly increased at 24 h ( p < 0.05) and 48 h ( p < 0.01), using a three-way ANOVA test. Moreover, live cell numbers decreased at 24 h and 48 h compared to control cells ( p < 0.00: Fig. 2 C & D). To confirm the cell-based assays, the expression of candidate genes involved in cell apoptosis, including Bax / Bcl2 ratio, Cycs , Tp53 , and Casp3 , were measured using qRT-PCR. All evaluated genes showed a significant increase at RNA level in ESL-treated cells treated with 25 µM, compared to control cells ( p < 0.05: Fig. 2 E). Afterward, the expression of the candidate genes was measured at protein levels. Our results showed an increased level of BAX (4.03-fold) and a decreased level of BCL2 (0.75-fold) in treated cells compared to control cells. Accordingly, the BAX/BCL2 ratio was estimated to be 5.37-fold in treated cells compared to control cells. Our results indicated a 0.23-fold decrease in proprotein (p)-CASP3 expression and an 8.64-fold increase in the expression of cleaved (c)-CASP3 in ESL-treated cells compared to the control cells. Moreover, the expression of P53 and CYCS as key regulators of cell apoptosis also increased 1.52- and 2.25-fold in treated cells, respectively (Fig. 2 F). Our results validated that ESL can induce cell apoptosis and decrease C6 GBM cell survival and viability.

ESL increased the apoptosis rate in the c6 cells. ( A & B ) C6 cells under various concentrations of ESL (0, 10, 25, and 50 µM) were stained with AO/EB. ESL significantly increased the apoptosis rate at 24 and 48 h (green dots are viable cells and red dots are apoptotic cells). ( C & D ) The C6 cells treated with ESL (25 µM) were stained by Annexin V-PI and analyzed using flow cytometry. ESL significantly increased the rate of apoptotic cells at 24 h ( p < 0.05) and 48 h ( p < 0.01) compared to control cells. Moreover, the number of live cells decreased in the C6 cells treated with ESL (24 h, p < 0.001; 48 h, p < 0.001). ( E ) The expression level of the genes involved in apoptosis was determined at the RNA level in the C6 cells treated with 25 µM of ESL, using qRT-PCR. Bax / Bcl2 ratio, the expression of Cycs , Tp53 ( p < 0.05), and Casp3 ( p < 0.01) significantly increased in treated cells compared to control cells. ( F ) The expression of the candidate genes was also measured at the protein level using a Western blot test. The expression of BAX, P53, cleaved CASP3, and CYCS increased while the expression of BCL2 and p-CASP3 decreased in the C6 cells treated with 25 µM of ESL compared to control cells. Scale bar: 200 μm. The original and uncropped blot images are presented in supplementary Figure XA

ESL arrested cell cycle in the G2/M phase

To assess the effect of ESL on the cell cycle status, C6 cells were treated with 25 µM of ESL and analyzed at 24 h and 48 h with flow cytometry. The results showed that ESL caused cell cycle arrest in the G2/M phase of the cell cycle after 24 h. The G2/M phase arrest was also visible at 48 h (Fig. 3 A). The expression of cell cycle-involved genes Cdkn1a , Cdk1 , and Ccnb1 at the RNA level did not show significant differences between treated and control cells (Fig. 3 B). However, the expression of these genes at the protein level increased in the ESL-treated cells compared to control cells (CDKN1A increased 2.49-fold; CCNB1 and CDK1 decreased 0.22- and 0.34-fold, respectively: Fig. 3 C). For the first time, our results indicated that ESL arrests the G2/M phase of the cell cycle.

ESL modulates the expression of the G2/M cell cycle regulatory proteins. (A) PI staining showed that treatment of the C6 cells with 25 µM ESL arrested the cell cycle in the G2/M phase at 24 and 48 h. (B) qRT-PCR from cells treated with ESL (25 µM for 48 h) were analyzed for the expression of Ccnd1 , Cdk1 , and Cdkn1a . (C) Western blot of lysates prepared from cells treated with ESL (25 µM for 48 h) was analyzed for the expression of CCNB1, CDK1, and CDKN1A proteins. The expression of p21, as a negative regulator, was increased, while the expression of CDK1 and CCNB1, as positive regulators, was decreased in treated cells compared to control cells. The original and uncropped blot images are presented in supplementary Figure XB

ESL suppressed tumor growth in an intracranial rat model of GBM: in vivo study

To confirm the potential inhibitory effects of ESL on tumor growth in vivo, we generated an intracranial C6 rat GBM model by injecting the C6 cells into the entorhinal cortex [ 26 ]. After 18 days, the MRI images showed tumor formation and growth in the VEH group (Fig. 4 A & B), whereas, administration of 30 mg/kg ESL profoundly suppressed tumor growth (Fig. 4 C & D). ESL-treatment suppressed tumor growth compared to the VEH group when calculated with MRI and Caliper ( p < 0.001: Fig. 4 F & G). In line with this, the tumor weight was substantially lower in the rats treated with 30 mg/kg ESL compared to the VEH treated group ( p < 0.01: Fig. 4 H). There was no significant change in the body weights resulting from ESL treatment (Fig. 4 E).

ESL significantly suppressed tumor growth in rat C6 glioma model. MRI images of rat C6 glioma model and tumor samples in VEH (A and B) and ESL-treated rats (C and D) . Body weight differences between the VEH and ESL groups did not show significant differences (E). Analysis of tumor size data using MRI (F) and caliper (G) indicated that tumor growth was significantly suppressed in the ESL group. (H) The tumor weight in the ESL-treated animals was remarkably lower compared to the VEH-treated counterparts

GBM is a malignant brain tumor with a short life expectancy [ 31 ]. The current treatment options are scarce and not sufficient to manage the disease. GBM cells ultimately develop resistance to radiation and chemotherapy, leading to tumor recurrence, remarking an urgent need for novel and effective treatment strategies for GBM. Specific chemotherapy for GBM is TMZ, but 50% of patients become resistant to this drug after treatment [ 13 ]. Subsequently, there is an extensive need for new drugs to manage post-TMZ resistance. In this study, we investigated for the first time the anticancer effects of ESL on C6 GBM cells both in vitro and in vivo.

Derivatives of dibenzoazepine have shown anticancer effects. CBZ, a first-generation dibenzoazepine, has been shown to reduce the viability of HT-29 human colon adenocarcinoma cells [ 22 ]. Besides, the protective effects of CBZ have been observed in breast cancer [ 32 , 33 ]. Moreover, OXC, a second-generation dibenzoazepine, has also shown anti-proliferative effects in various malignant cells, including HeLa, MCF7, and HepG2 [ 34 ]. In a recent in vitro study by Dao Trong et al. (2023), OXC demonstrated antiproliferative effects on human Isocitrate dehydrogenase (IDH) mutant glioma stem-like cells in vitro [ 35 ]. Here, we report the anticancer effects of ESL on C6 glioma cells for the first time. Our results showed that ESL significantly suppresses C6 cell viability and proliferation in the MTT and soft agar colony formation assays. Besides, we showed that ESL reduces migration of the C6 cells with enhancing concentrations captured by wound healing assay. Dibenzazepine drugs inhibit the voltage-gated Na + channels, which are involved in cell processes including phagocytosis, endocytosis, secretion, proliferation, and differentiation in unstimulated cells. It has been reported that ESL has inhibitory effects on Nav1.5. By using Nav1.5 and voltage-gated sodium channels, cancer cells enhance their invasion and metastasis [ 36 , 37 , 38 ]. Accordingly, inhibition of these channels may directly or indirectly affect tumor cell growth, proliferation and migration.

In the next step, our staining results demonstrate that ESL increases the apoptosis in C6 GBM cells. By disrupting the expression of tumor suppressor genes, cancer cells can inhibit apoptosis and increase cell viability and proliferation. Apoptosis induction is a primary feature of anticancer drugs [ 39 ]. Our results showed a significant increase in the BAX/BCL2 ratio at RNA and protein levels. The anti-apoptotic protein BCL2 and pro-apoptotic member BAX are released from the mitochondria and play a crucial role in the process of apoptosis [ 40 ]. The BAX/BCL2 ratio is a rheostat determining whether the cells are undergoing apoptosis or not [ 41 ]. The release of CYCS from mitochondria is the turning point to start the irreversible process of apoptosis. CYCS converts p-CASP9 to active CASP9, which cleaves p-CASP3 to its activated form. As a consequence, the apoptosis process occurs irreversibly [ 42 ]. Our results indicated that the expression of pro-caspase 3 and its cleaved form were downregulated and upregulated, respectively, in the ESL-treated C6 cells. In line with our findings, Sohaib et al. reported CBZ-induced apoptosis of HT-29 cells through ROS and Caspase3 induction [ 22 ]. Moreover, the expression of cytochrome C also increased in ESL-treated C6 cells compared to control cells. Our findings correlate with the results reported by Song et al. that OXC can increase the apoptosis rate in brain cells [ 43 ]. We showed a significant increase in the Tp53 at the RNA level, confirmed by its enhancement at the protein level in the ESL-treated C6 cells. P53 is a protein with many biological functions that regulate intrinsic and extrinsic apoptotic pathways [ 44 ]. For example, P53 binds to the promoter of the Bax and regulates the expression of this gene [ 45 ].

Subsequent experiments revealed that ESL arrests C6 cell cycle progression in the G2/M phase. We found that the expression of CDKN1A, a cell cycle inhibitor, increased while the expression of CDK1 and CCNB1, cell cycle inducers, decreased at the protein level, albeit we did not find a significant difference at the RNA level. According to this, ESL probably acts as a translation regulator of the factors involved in the cell cycle. Our results correlate with the ones reported by Lee et al. (2016). They revealed that OXC affects the cell cycle at the G2/M phase in GBM cells, including U-87 MG and T98G [ 25 ]. The cell cycle is a vital process in cell proliferation. Cancer cells can dysregulate the cell cycle checkpoints and enhance cell proliferation. Hence, cell cycle regulation is the main focus of some anticancer strategies [ 46 ]. Cell damage during apoptosis leads to P53 enhancement, activating CDKN1A, which acts as an inhibitor of CCNB1/CDK1. The latter complex is the inducer of cell cycle arrest in G2/M phase [ 47 ]. Cell arrest in this phase will cause cell death via mitotic catastrophe in cells with damaged DNA [ 48 ].

This report presents the first finding that ESL suppresses GBM growth in a rat C6 glioma cell model. Our results also showed a high correlation between the three parameters of tumor weight and tumor volume (MRI and caliper measurements) [ 26 ]. Orthotropic C6 allografts provide highly similar tumors to human GBM characteristics regarding genetic profile, growth patterns, and invasion. Hence, our findings on the antitumor effects of ESL may pave the way for more research. Here, to fully understand the tumor growth pattern and better observe the drug effect, we recommend serial monitoring of the tumor volume by MRI throughout the experimental period. While it is common to only measure the tumor volume at the end of the study, measurements on days 7, 13 and 18 could be considered as optimal. This was a limitation of our study. On the other hand, repetitive MRI sessions are quite time and money-consuming, alongside the repetitive anesthesia could be hazardous to the rats. However, during the establishment of the tumor model, we did measure tumor volumes by MRI on days 10 and 18 post-cell inoculations to ensure consistent tumor growth in all control animals. After ensuring the establishment of the model, in the continuance of the work, the final measurements were done only on the 18th day. Undoubtedly, additional MRI measurements during the experiment would be highly informative. Our novel findings on the significant antitumor effects of ESL in the C6 rat glioblastoma model may pave the way for further research.

Overall, we present the first report showing ESL inhibits the viability, proliferation, and migration of the C6 cells thorough inducing apoptosis and arrest of the cell cycle in the G2/M phase in vitro. Furthermore, ESL profoundly suppresses tumor growth in vivo. Based on these encouraging findings further research on ESL in the management of glioblastoma is highly recommended.

Data availability

Data is provided within the manuscript or supplementary information files.

Abbreviations

acridine orange/ethidium bromide

Carbamazepine

Eslicarbazepine

fetal bovine serum

Glioblastoma multiforme

Human Isocitrate dehydrogenase

magnetic resonance imaging

3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide

Oxcarbazepine

Phosphate-buffered saline

propidium iodide

quantitative reverse transcriptase- Polymerase chain reaction

temozolomide

World Health Organization

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This project was supported by the Iran National Science Foundation (INSF) (grant number 4005050).

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Nastaran Afsordeh, Safura Pournajaf, Amir Shojaei, Javad Mirnajafi-Zadeh & Mohammad Hossein Pourgholami

Biochemical Neuroendocrinology, Division of Experimental Medicine, Faculty of Medicine and Health Sciences, Institut de Recherches Cliniques de Montréal (IRCM), McGill University, Montréal, H2W 1R7, Canada

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N. A: Investigation, Formal analysis, Writing – original draft, Writing – review; editing.S.P: Investigation, Formal analysis, Writing – review & editing.H.B: Investigation, Formal analysis, Writing – review & editing.F. M: Investigation, Formal analysis.J. M-Z: Conceptualization, Supervision, Resources.A. Sh: Conceptualization, Supervision, Resources.M. P: Conceptualization, Methodology, Supervision, Resources, Funding acquisition, Writing – review & editing All authors reviewed the manuscript.

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Afsordeh, N., Pournajaf, S., Bayat, H. et al. Eslicarbazepine induces apoptosis and cell cycle arrest in C6 glioma cells in vitro and suppresses tumor growth in an intracranial rat model. BMC Cancer 24 , 1099 (2024). https://doi.org/10.1186/s12885-024-12840-3

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As a result, a variety of novel study designs have evolved to help further individualize patient care and in some cases allow faster evidence generation. These new methods are expanded on within the chapter and include micro-randomized trials (MRTs), n-of-1, site-less design, and stepped wedge trials. Furthermore, we discuss study methodologies ...
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Abstract. Experimental research design is centrally concerned with constructing research that is high in causal (internal) validity. Randomized experimental designs provide the highest levels of causal validity. Quasi-experimental designs have a number of potential threats to their causal validity. Yet, new quasi-experimental designs adopted ...
Exploring Experimental Research: Methodologies, Designs, and
Core theme of this book is a heuristic called the question-design-analysis bridge: there is a bridge connecting research questions and hypotheses, experimental design and sampling procedures, and ...
A novel experimental technique and its application to study the effects
A novel experimental technique and its application to study the effects of particle density and flow submergence on bed particle saltation Mohammad Amir Research Fellow, School of Engineering, University of Aberdeen, Aberdeen, UK (currently Fluid Mechanics Development Engineer, Silixa Ltd, 230 Centennial Park, Centennial Avenue, Elstree ...
Experimental Research
Experimental science is the queen of sciences and the goal of all speculation. Roger Bacon (1214-1294) Download chapter PDF. Experiments are part of the scientific method that helps to decide the fate of two or more competing hypotheses or explanations on a phenomenon. The term 'experiment' arises from Latin, Experiri, which means, 'to ...
A novel experimental approach to study disobedience to authority
Inspired by subsequent versions of Milgram-like paradigms and by combining the strengths of each, this paper presents a novel experimental approach to the study of (dis)obedience to authority ...
Experimental study on a novel self-driven multi-heat sinks system
Experimental study on the heat transfer characteristics of a novel self-driven cooling system[J] Int. J. Heat. Mass Transf. , 221 ( 2024 ) , Article 125085 , 10.1016/j.ijheatmasstransfer.2023.125085
Sage Research Methods
Experimental Design: Procedures for the Behavioral Sciences. This classic text, with a reputuation for accessibility and readability, has been revised and updated to make learning design concepts even easier. Roger E. Kirk shows how three simple experimental designs can be combined to form a variety of complex designs.
PDF A novel experimental approach to study disobedience to authority
presents a novel experimental approach to the study of (dis)obedience to authority. Volunteers are recruited in pairs and take turns to be 'agents' or 'victims', making the procedure fully ...
(PDF) An Introduction to Experimental Design Research
P. Cash et al. (eds.), Experimental Design Research, DOI 10.1007/978-3-319-33781-4_1. Abstract Design research brings together inﬂuences from the whole gamut of. social, psychological, and more ...
Experimental and Comparative Study on Compressive Strength of GFRP
The experimental results indicate that the increase in the longitudinal ρf increases the failure load by 125% and decreases the crack width and mid-span deflection by 78% and 57%, respectively.
Experimental Design Research
This book presents a new, multidisciplinary perspective on and paradigm for integrative experimental design research. It addresses various perspectives on methods, analysis and overall research approach, and how they can be synthesized to advance understanding of design. It explores the foundations of experimental approaches and their utility in this domain, and brings together analytical ...
How Experts Solve a Novel Problem in Experimental Design
The results of those studies suggust that experts have learned moder-. ately general strategies such as mental simulation that are used in domains such as software design (Adelson & Soloway, 1985). When they are con- fronted with novel problems, experts use those strategies to solve novel pro- blems.
5: Experimental Design
Experimental design is a discipline within statistics concerned with the analysis and design of experiments. Design is intended to help research create experiments such that cause and effect can be established from tests of the hypothesis. We introduced elements of experimental design in Chapter 2.4. Here, we expand our discussion of ...
Novel experimental approach to study aroma release upon reconstitution
This study presents an experimental approach to study the kinetics and fast release of volatile organic compounds (VOCs) upon reconstitution of instant coffee products. A sampling setup coupled to PTR-ToF-MS (Proton Transfer Reaction Time-of-Flight Mass Spectrometry) for the automated and reproducible reconstitution of instant coffee products ...
3-in-1 Blood Pressure Pill Could Be Treatment Advance
Novel low-dose 3-in-1 blood pressure pill significantly outperforms standard care, study shows. Over 80% of patients achieved control within a month. ... -- An experimental three-in-one blood pressure pill works better than layering on meds one at a time, a new clinical trial shows. After a month on the combo pill, 81% of patients had their ...
Modeling of EDM parameter with novel W/O nano-emulsion
This study investigates the potential of a novel water-in-oil nano-emulsion (W/O) synthesized from non-edible refined jatropha oil as a dielectric fluid to enhance the electric discharge machining (EDM) process. W/O nano-emulsion was synthesized in two different surfactant concentrations, namely 10% and 15%. Influence of different input parameters, including current, pulse-on time, pulse-off ...
A comprehensive study on Mecanum wheel-based mobility and ...
Experimental validations, including shock absorption and positioning tests, demonstrate that our suspension system markedly enhances the wheelchair's control performance and stability, thereby ...
Eslicarbazepine induces apoptosis and cell cycle arrest in C6 glioma
Based on these novel findings, ESL has the potential for further experimental and clinical studies in glioblastoma. Glioblastoma multiforme (GBM) is the most malignant brain tumor, with a poor prognosis and life expectancy of 14-16 months after diagnosis. The standard treatment for GBM consists of surgery, radiotherapy, and chemotherapy with ...

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A novel experimental approach to study disobedience to authority

Associated Data

Introduction

Participants

Method and Material

General data analyses

Number of shocks given in the free-choice condition

Prosocial disobedience across variants

Reasons for prosocial disobedience

Feeling responsible, bad and sorry

Identification with the experimenter

Estimated pain of the ‘victim’

Identification with the ‘victim’

Correlations between the behavior of pairs of participants

Individual differences associated with prosocial disobedience

Reasons for obedience

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Author contributions

Data availability

Renaissance of the Weird: Experimental Fiction as the New American Normal

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Experimental Research Design — 6 mistakes you should never make!

What Is Experimental Research Design?

When Can a Researcher Conduct Experimental Research?

Importance of Experimental Research Design

Types of Experimental Research Designs

1. Pre-experimental Research Design

2. True Experimental Research Design

3. Quasi-experimental Research Design

Advantages of Experimental Research

6 Mistakes to Avoid While Designing Your Research

1. Invalid Theoretical Framework

2. Inadequate Literature Study

3. Insufficient or Incorrect Statistical Analysis

4. Undefined Research Problem

5. Research Limitations

6. Ethical Implications

Experimental Research Design Example

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