Many Minds

Hi friends! We're taking a much-needed August pause—we'll have new episodes for you in September. In the meanwhile, enjoy this pick from our archives! _____ [originally aired February 8, 2024] Where do memories live in the brain? If you've ever taken a neuroscience class, you probably learned that they're stored in our synapses, in the connections between our neurons. The basic idea is that, whenever we have an experience, the neurons involved fire together in time, and the synaptic connections between them get stronger. In this way, our memories for those experiences become minutely etched into our brains. This is what might be called the synaptic view of memory—it's the story you'll find in textbooks, and it's often treated as settled fact. But some reject this account entirely. The real storehouses of memory, they argue, lie elsewhere.  My guest today is Dr. Sam Gershman. Sam is Professor of Psychology at Harvard University, and the director of the Computational Cognitive Neuroscience Lab there. In a recent paper, he marshals a wide-ranging critique of the synaptic view. He makes a compelling case that synapses can't be the whole story—that we also have to look inside the neurons themselves.  Here, Sam and I first discuss the synaptic view and the evidence that seems to support it. We then talk about some of the problems with this classic picture. We consider, for example, cases where memories survive the radical destruction of synapses; and, more provocatively, cases where memories are formed in single-celled organisms that lack synapses altogether. We talk about the dissenting view, long lurking in the margins, that intracellular molecules like RNA could be the real storage sites of memory. Finally, we talk about Sam's new account—a synthesis that posits a role for both synapses and molecules. Along the way we touch on planaria and paramecia; spike-timing dependent plasticity; the patient H.M.; metamorphosis, hibernation, and memory transfer; the pioneering work of Beatrice Gelber; unfairly maligned ideas; and much, much more. Before we get to it, one important announcement: Applications are now open for the 2024 Diverse Intelligences Summer Institute (or DISI)! The event will be held in beautiful, seaside St Andrews, Scotland, from June 30 to July 20. If you like this show—if you like the conversations we have and the questions we ask—it's a safe bet that you'd like DISI. You can find more info at disi.org—that's disi.org. Review of applications will begin on Mar 1, so don't delay.  Alright friends, on to my conversation about the biological basis of memory with Dr. Sam Gershman. Enjoy!   Notes and links 4:00 - A general audience article on planarian memory transfer experiments and the scientist who conducted them, James V. McConnell.  8:00 - For more on Dr. Gershman’s research and general approach, see his recent book and the publications on his lab website.  9:30 - A brief video explaining long-term potentiation. An overview of “Hebbian Learning.” The phrase “neurons that fire together wire together” was, contrary to widespread misattribution, coined by Dr. Carla Shatz here. 12:30 - The webpage of Dr. Jeremy Gunawardena, Associate Professor of Systems Biology at Harvard University. A recent paper from Dr. Gunawardena’s lab on the avoidance behaviors exhibited by the single-celled organism Stentor (which vindicates some disputed, century-old findings).   14:00 - A recent paper by C. R. Gallistel describing some of his views on the biological basis of memory.   19:00 - The term “engram” refers to the physical trace of a memory. See recent reviews about the so-called search for the engram here, here, and here.   20:00 - An article on the importance of H.M. in neuroscience.  28:00 - A review about the phenomenon of spike-timing dependent plasticity. 33:00 - An article, co-authored by former guest Dr. Michael Levin, on the evidence for memory persistence despite radical remodeling of brain structures. See our episode with Dr. Levin here. 35:00 - A study reporting the persistence of memories in decapitated planarians. A popular article about these findings.  36:30 - An article reviewing one chapter in the memory transfer history. Another article reviewing evidence for “vertical” memory transfer (between generations). 39:00 - For more recent demonstrations of memory transfer, see here and here. 40:00 - A paper by Dr. Gershman, Dr. Gunawardena, and colleagues reconsidering the evidence for learning in single cells and describing the contributions of Dr. Beatrice Gelber. A general audience article about Gelber following the publication of the paper by Dr. Gershman and colleagues. 45:00 – A recent article arguing for the need to understand computation in single-celled organisms to understand how computation evolved more generally.  46:30 – Another study of classical conditioning in paramecia, led by Dr. Todd Hennessey. 49:00 – For more on plant signaling, see our recent episode with Dr. Paco Calvo and Dr. Natalie Lawrence.  56:00 – A recent article on “serial reversal learning” and its neuroscientific basis.  1:07:00 – A 2010 paper demonstrating a role for methylation in memory.   Recommendations The Behavior of the Lower Organisms, by Herbert Spencer Jennings Memory and the Computational Brain, by C. R. Gallistel and Adam Philip King Wetware, by Dennis Bray   Many Minds is a project of the Diverse Intelligences Summer Institute, which is made possible by a generous grant from the John Templeton Foundation to Indiana University. The show is hosted and produced by Kensy Cooperrider, with help from Assistant Producer Urte Laukaityte and with creative support from DISI Directors Erica Cartmill and Jacob Foster. Our artwork is by Ben Oldroyd. Our transcripts are created by Sarah Dopierala. Subscribe to Many Minds on Apple, Stitcher, Spotify, Pocket Casts, Google Play, or wherever you listen to podcasts. You can also now subscribe to the Many Minds newsletter here! We welcome your comments, questions, and suggestions. Feel free to email us at: manymindspodcast@gmail.com. For updates about the show, visit our website or follow us on Twitter (@ManyMindsPod) or Bluesky (@manymindspod.bsky.social).

Hi friends! We're taking a much-needed August pause—we'll have new episodes for you in September. In the meanwhile, enjoy this pick from our archives! _____ [originally aired May 30, 2024] Maybe your idea of spiders is a bit like mine was. You probably know that they have eight legs, that some are hairy. Perhaps you imagine them spending most of their time sitting in their webs—those classic-looking ones, of course—waiting for snacks to arrive. Maybe you consider them vaguely menacing, or even dangerous. Now this is not all completely inaccurate—spiders do have eight legs, after all—but it's a woefully incomplete and drab caricature. Your idea of spiders, in other words, may be due for a refresh.  My guest today is Dr. Ximena Nelson, Professor in the School of Biological Sciences at the University of Canterbury, in New Zealand. Ximena is the author of the new book, The Lives of Spiders. It’s an accessible and stunningly illustrated survey of spider behavior, ecology, and cognition.  In this conversation, Ximena and I do a bit of ‘Spiders 101’. We talk about spider senses—especially how spiders use hairs to detect the minutest of vibrations and how they see, usually, with four pairs of eyes. We talk about web-making—which, by the way, the majority of spiders don't do—and silk-making—which all do, but for more reasons than you may realize. We talk about how spiders hunt, jump, dance, pounce, plan, decorate, cache, balloon, and possibly count. We talk about why so many spiders mimic ants. We take up the puzzle of “stabilimenta”. We talk about whether webs constitute an extended sensory apparatus—like a gigantic ear—and why spiders are an under-appreciated group of animals for thinking about the evolution of mind, brain, and behavior. Alright friends, this one is an absolute feast. So let's get to it. On to my conversation with Dr. Ximena Nelson. Enjoy!    A transcript of this episode is available here.   Notes and links 3:00 – A general audience article about our “collective arachnid aversion” to spiders.  8:00 – An academic article by Dr. Nelson about jumping spider behavior.  8:30 – In addition to spiders, Dr. Nelson also studies kea parrots (e.g., here).  12:00 – A popular article about the thousands of spider species known to science—and the thousands that remain unknown. 16:30 – A popular article about a mostly vegetarian spider, Bagheera kiplingi. 18:00 – For the mating dance of the peacock spider, see this video. 20:00 – A recent study on spider “hearing” via their webs. 24:00 – The iNaturalist profile of the tiger bromeliad spider.  29:30 – A recent study of extended sensing in humans during tool use.  33:00 – A popular discussion of vision (and other senses) in jumping spiders.  40:00 – An earlier popular discussion of spider webs and silk.  45:00 – For a primer on bird’s nests, see here.  48:00 – An article describing the original work on how various drugs alter spiders’ webs.  49:00 – A recent salvo in the long-standing stabilimenta debate. 54:00 – A video about “ballooning” in spiders. 57:00 ­– An article by Dr. Nelson and a colleague about jumping spiders as an important group for studies in comparative cognition. 1:01:00 – A study of reversal learning in jumping spiders, which found large individual differences. 1:07:00 – A study of larder monitoring in orb weaver spiders. 1:10:00 – A study by Dr. Nelson and a colleague on numerical competence in Portia spiders. 1:16:00 – An academic essay on the so-called insect apocalypse.   Recommendations Spider Behaviour: Flexibility and Versatility, by M. Herberstein ‘Spider senses – Technical perfection and biology,’ by F. Barth ‘Extended spider cognition’, by H. Japyassú and K. Lala   Many Minds is a project of the Diverse Intelligences Summer Institute, which is made possible by a generous grant from the John Templeton Foundation to Indiana University. The show is hosted and produced by Kensy Cooperrider, with help from Assistant Producer Urte Laukaityte and with creative support from DISI Directors Erica Cartmill and Jacob Foster. Our artwork is by Ben Oldroyd. Our transcripts are created by Sarah Dopierala. Subscribe to Many Minds on Apple, Stitcher, Spotify, Pocket Casts, Google Play, or wherever you listen to podcasts. You can also now subscribe to the Many Minds newsletter here! We welcome your comments, questions, and suggestions. Feel free to email us at: manymindspodcast@gmail.com. s For updates about the show, visit our website or follow us on Twitter (@ManyMindsPod) or Bluesky (@manymindspod.bsky.social).

When you hear the word "shaman," I'm guessing a web of associations starts to form in your mind. Perhaps you imagine strange ceremonies and strong substances; maybe you think of an earlier time when magic and superstition reigned. But shamanism is not just some relic of the past, or a curio from exotic lands. It's part of our present, and it will almost certainly be part of our future. This is because the roots of shamanism lie within us all. My guest today is Dr. Manvir Singh. Manvir is an Assistant Professor of Anthropology at the University of California, Davis and a regular contributor to The New Yorker. He's also the author of a new book—Shamanism: The Timeless Religion. Here, Manvir and I talk about his fieldwork with Mentawai shamans in Indonesia. We discuss what makes a shaman a shaman and consider the cognitive building blocks that make shamanism so widespread and so appealing. We discuss the shamanic origins of Abrahamic religions. We consider how, over the course of history, shamanism has repeatedly resurged, despite attempts to snuff it out. And we also talk about the various forms and flavors that shamanism takes in contemporary Western societies. Along the way, Manvir and I touch on: drumming, fasting, and the “dark tent”; Jesus; experimental Edens; witches, prophets, and messiahs; glossolalia; disenchantment and re-enchantment; the rise of neoshamanism; Paleolithic rock art; hedge wizards and tech CEOs; Western exceptionalism; and the routinization of charisma. If you enjoy this episode, I highly recommend that you check out Manvir's book—it's a captivating blend of narrative and ideas and it goes far beyond what we were able to talk about here. I'll also flag that this is Manvir's second time on Many Minds. Back in July of 2020 we had another conversation—broader in scope—where we talked about shamanism but also Manvir's work on witches, stories, and music. So you might check that one out as well. Alright friends, on to my conversation with Dr. Manvir Singh. Enjoy!   A transcript of this episode is available here.   Notes and links 4:00 – For video examples of shamanic rituals from around the world, see Dr. Singh’s recent thread on  Bluesky / Twitter. 12:30 – On the idea of “cultural attraction” and “cultural attractors,” see here and here. For a recent treatment of the idea of “super-attractors,” see Dr. Singh’s preprint here. 16:00 – On the case of cultural loss among the Northern Aché, see the recent work by Dr. Singh and a colleague. 17:30 – For more on Dr. Singh’s theoretical framework for understanding shamanism, see his earlier academic paper. 19:00 – The 2005 review of altered states of consciousness by Vaitl et al. For more on psychedelics and altered states, see our recent episode with Chris Letheby. 29:00 – Mircea Eliade’s classic work on shamanism—Shamanism: Archaic Techniques of Ecstasy. 34:00 – For the book by Martin Riesebrodt on the nature of religion, see here. 36:00 – For more on the human propensity for ritual, see our earlier episode with Dimitris Xygalatas. 43:00 – For one influential interpretation of Paleolithic rock art as evidence for shamanism, see David Lewis-Williams’ book, Mind in the Cave: Consciousness and the Origins of Art. 52:00 – For a discussion of psychedelics and organized religion that touches on the “routinization of charisma,” see this article by Michael Pollan. 54:00 – For more about the case of Alice Auma, see Dr. Singh’s recent piece in The New Yorker. 1:00:30 – For more about neoshamanism and Michael Harner, see the website of the Foundation for Shamanic Studies—www.shamanism.org. 1:04:00 – For the analysis of financial managers by Samuel Johnson, see here.  1:06:00 – For more on the quasi-shamanic flavor of tech CEOs, see Rakesh Khurana’s book, Searching for a Corporate Savior: The Irrational Quest for Charismatic CEOs. 1:08:00 – See, again, Dr. Singh’s recent piece in The New Yorker in which he discusses Trump and prophet-like status. 1:13:00 – For Dr. Singh’s work on other complex cultural traditions, see the website for his lab.   Recommendations The Sambia: Ritual, Sexuality, and Change in Papua New Guinea, by Gilbert Herdt The Falling Sky: Words of a Yanomami Shaman, by Davi Kopenawa & Bruce Albert   Many Minds is a project of the Diverse Intelligences Summer Institute, which is made possible by a generous grant from the John Templeton Foundation to Indiana University. The show is hosted and produced by Kensy Cooperrider, with help from Assistant Producer Urte Laukaityte and with creative support from DISI Directors Erica Cartmill and Jacob Foster. Our artwork is by Ben Oldroyd. Our transcripts are created by Sarah Dopierala. Subscribe to Many Minds on Apple, Stitcher, Spotify, Pocket Casts, Google Play, or wherever you listen to podcasts. You can also now subscribe to the Many Minds newsletter here! We welcome your comments, questions, and suggestions. Feel free to email us at: manymindspodcast@gmail.com. s For updates about the show, visit our website or follow us on Twitter (@ManyMindsPod) or Bluesky (@manymindspod.bsky.social).

Childhood is a special time, a strange time. Children are adored and catered to—they're given their own menus and bedrooms. They're considered delicate and precious, and so we cushion them from every imaginable risk. Kids are encouraged to play, of course—but very often it's under the watchful eye of anxious adults. This, anyway, is how childhood looks in much of the United States today. But is this the way childhood looks everywhere? Is this the way human childhoods have always been? My guests today are Dr. Dorsa Amir and Dr. Sheina Lew-Levy. Dorsa is an Assistant Professor of Psychology & Neuroscience at Duke University, where she runs the Mind and Culture Lab. Sheina is an Associate Professor of Psychology at Durham University in the UK, where she co-directs the Forager Child Studies research group. Both Sheina and Dorsa have spent much of their careers thinking about how childhoods differ across cultures—and why. In this conversation, I talk with Dorsa and Sheina about their fieldwork with indigenous groups in Ecuador and the Congo, respectively. We discuss the different ways that childhood differs in these places—for instance, in terms of parents' attitudes toward risk, in terms of the social structures and activities in which kids are embedded, and in terms of the freedom that children are granted. We discuss developmental psychology's "WEIRD problem." We talk about the quasi-autonomous cultures that children create among themselves—sometimes called "peer cultures"—and discuss how these kid-driven cultures end up shaping and benefit the larger community. Along the way, we touch on adult supremacy, adverse childhood experiences, walking the forest and climbing papaya trees, parenting norms, ding dong ditch and "nananabooboo", the pioneering work of the folklorists Iona and Peter Opie, teaching, toys, and the enduring question of what childhood is for.   Alright friends, lots to think about here. On to my conversation with Sheina Lew-Levy and Dorsa Amir. Enjoy!   A transcript of this episode is available here.   Notes and links 9:30 – For an overview of work on how culture shapes motor development, see here. 11:00 – The paper by Dr. Lew-Levy’s and a colleague about “walking the forest.” 16:00 – Dr. Amir’s TedX talk, ‘How the Industrial Revolution Changed Childhood.’ 17:30 – For some of Dr. Amir’s work on risk across cultures, see here. 35:00 – For a recent paper by Dr. Lew-Levy and colleagues about the evolution of childhood, see here. 39:00 – The popular article by Ann Gibbons, ‘The Birth of Childhood.’ 41:00 – For the idea of the “patriarch hypothesis,” see here. 42:00 – For more on the “WEIRD problem” in developmental psychology, see here. 48:00 – A paper by Dr. Lew-Levy and colleagues about toys in hunter-gatherer groups. For more on the material culture of childhood, see our earlier episode with Michelle Langley. 52:00 – A recent paper by Dr. Lew-Levy on the prevalence of “child-to-child” teaching. 56:00 – A paper by Dr. Amir and a colleague about the concept of “adverse childhood experiences” in cross-cultural perspective. 1:04:00 – The paper by Dr. Amir and Dr. Lew-Levy on “peer cultures” and children as agents of cultural adaptation. 1:08:00 – For more on the idea of children as the "research and development" wing of the species, see our earlier episode with Alison Gopnik. 1:10:00 – For more on the Opies, see here. 1:13:00 – For the work of (past guest) Olivier Morin on children’s culture, see here. 1:23:00 – For the paper by Dr. Camilla Morelli, ‘The River Echoes with Laughter,’ see here.   Recommendations The Lore and Language of Schoolchildren, by Iona and Peter Opie The Gardener and the Carpenter, by Alison Gopnik The Anthropology of Childhood, by David Lancy Intimate Fathers, by Barry Hewlett   Many Minds is a project of the Diverse Intelligences Summer Institute, which is made possible by a generous grant from the John Templeton Foundation to Indiana University. The show is hosted and produced by Kensy Cooperrider, with help from Assistant Producer Urte Laukaityte and with creative support from DISI Directors Erica Cartmill and Jacob Foster. Our artwork is by Ben Oldroyd. Our transcripts are created by Sarah Dopierala. Subscribe to Many Minds on Apple, Stitcher, Spotify, Pocket Casts, Google Play, or wherever you listen to podcasts. You can also now subscribe to the Many Minds newsletter here! We welcome your comments, questions, and suggestions. Feel free to email us at: manymindspodcast@gmail.com.    For updates about the show, visit our website or follow us on Twitter (@ManyMindsPod) or Bluesky (@manymindspod.bsky.social).

Molly Crockett, a Psychology Professor at Princeton specializing in moral and social cognition, shares insights on AI's transformative potential in science. She discusses four visions of AI: as Oracle, Surrogate, Quant, and Arbiter, revealing how each can mislead our understanding of science. The conversation tackles the ethical implications of using AI as experimental subjects, the risks of anthropomorphizing technology, and the dangers of over-reliance on AI, stressing the need for a balanced approach to enhance human understanding and creativity in research.

Puppies wrestling and mock-biting each other. Toddlers playing hide and seek. Kittens pouncing—repeatedly—on a toy mouse. You've no doubt looked on at scenes like this with amusement. And you've no doubt seen some of those viral videos—of ravens sledding down hills, of bumble bees playing with balls. All these moments make us smile, maybe even giggle. But the scientific questions they raise merit serious attention. Where do we see play in the animal kingdom? Where do we not? What functions does play serve? Do we—and many other creatures—have an elemental need for play? My guest today is Dr. Gordon Burghardt. Gordon is a longtime Professor in the Department of Psychology and the Department of Ecology and Evolutionary Biology at the University of Tennessee. For decades now, Gordon has been a pioneer in the study of animal play, with a particular focus on play in reptiles and other animals not usually considered playful. His 2005 book, The Genesis of Animal Play, remains a landmark in the field. Here, Gordon and I talk about the major types of play: locomotor play, object play, and social play. We discuss the five criteria he has proposed for recognizing play across animal taxa. We survey several of the functions of play that have been proposed over the decades, and discuss how—in the end—play doesn't seem to have just one function. We also talk about human play—about what sets it apart, and about the possibility that play lies at the root of many of the capacities and institutions we think of as distinctively, impressively human. Along the way, Gordon and I touch on play in bears, pythons, turtles, fruit flies, and octopuses. We consider play between members of taxonomically distant species. We talk about “self-handicapping”; the surplus resource theory of play; the importance of "risky play" and "free play"; the immersive quality of play; bodily and vocal play signals in mammals; and whether human play is increasingly endangered.  Without further ado, here's my conversation with Dr. Gordon Burghardt. Enjoy!   A transcript of this episode is available here.   Notes and links 3:00 – A news article on the finding of “play-like” behavior in fruit flies. The original study. 4:30 – For recent reviews of play by Dr. Burghardt and colleagues, covering the three major types of play, the five criteria for recognizing play, and many other topics, see here, here, and here. 12:00 – For more on Dr. Burghardt’s early research and hand-rearing of black bears, see here. 23:30 – For the recent study on ball play in bumble bees, see here.  26:00 – For an example of studies examining self-handicapping, see this study on belugas.  27:00 – For a video of a bull and goat butting heads, see here. For more on cross-species play, see this recent paper by Dr. Burghardt and a colleague. 31:00 – For more on the “relaxed open mouth expression” and “play face,” see our previous episode on the origins of the smile.  For a recent study about such expressions possibly attested in dolphins, see here. 44:00 – For the book by Johan Huizinga, see here. For some of Dr. Burghardt’s ideas about the connections between play and certain aspects of human culture, see here.  54:00 – For research on the value of “risky play,” see work by Dr. Ellen Sandseter. For an article connecting “free play” and children’s mental health, see here.   Recommendations Kingdom of Play, by David Toomey   Many Minds is a project of the Diverse Intelligences Summer Institute, which is made possible by a generous grant from the John Templeton Foundation to Indiana University. The show is hosted and produced by Kensy Cooperrider, with help from Assistant Producer Urte Laukaityte and with creative support from DISI Directors Erica Cartmill and Jacob Foster. Our artwork is by Ben Oldroyd. Our transcripts are created by Sarah Dopierala. Subscribe to Many Minds on Apple, Stitcher, Spotify, Pocket Casts, Google Play, or wherever you listen to podcasts. You can also now subscribe to the Many Minds newsletter here! We welcome your comments, questions, and suggestions. Feel free to email us at: manymindspodcast@gmail.com.  For updates about the show, visit our website or follow us on Twitter (@ManyMindsPod) or Bluesky (@manymindspod.bsky.social).

René Mõttus, a Professor of Psychology at the University of Edinburgh and a researcher in human personality, dives deep into the nuances of the ‘big five’ personality traits. He discusses how these traits influence career success and life satisfaction, and whether they truly reflect human nature. The conversation explores personality change over time, the interplay between genetics and environment, and even the role of birth order. René also critiques existing personality assessments, suggesting a need for more nuanced models in understanding ourselves.

Some call it the "psychedelic renaissance." In the last decade or so, interest in psychedelic drugs has surged—and not just among Silicon Valley types and psychiatrists and neuroscientists. It's also surged among a stereotypically soberer crowd: academic philosophers. The reasons are clear. With their varied and sometimes transformative effects, psychedelics raise ethical questions, epistemological questions, metaphysical questions, questions about the nature of experience and the nature of the mind. My guest today is Dr. Chris Letheby. Chris is a philosopher of cognitive science at the University of Western Australia and the author of the 2021 book, Philosophy of Psychedelics. Here, Chris and I talk about the so-called classic psychedelics—LSD, psilocybin, ayahuasca, and others—and how interest in them has gone through three distinct waves. We discuss the effects that these substances seem to have, in particular their capacity to treat certain psychiatric conditions and their tendency to induce "mystical-like" experiences. We consider the idea that psychedelics might serve as agents of moral enhancement. And we dig into the psychological and neural mechanisms by which psychedelics seem to have their diverse—and often salutary—effects. Along the way, we talk about ontological shock, comforting delusions, brain plasticity, unselfing, microdosing, placebo effects and adverse effects, physicalism and idealism, the REBUS model, environmental virtues, plant consciousness, meditation, and much more. Maybe this is obvious but this episode is not just for the seasoned psychonauts out there. Whatever your personal experience with these substances, they offer a distinctive window into the mind—a new way of grappling with big questions. Perhaps this much is also obvious but we're not encouraging or endorsing the use of psychedelics here—just offering a little fuel for your intellectual fires! Alright friends, on to my conversation w/ Dr. Chris Letheby. Enjoy!   A transcript of this episode is available here.    Notes and links 4:00 – For a brief historical overview of research into psychedelics, see this paper. 8:30 – For work by an early trailblazer in the philosophy of psychedelics, see Thomas Metzinger’s Being No One. 12:30 – For our earlier episode on the psychology and philosophy of visual illusions, see here.  18:00 – For a history of the concept of “set and setting,” see here. 19:00 – A 2024 review of “adverse events” in classic psychedelics. 26:00 – A blog post on the history of the term “psychedelic.” 27:00 – A recent review and meta-analysis of the use of psychedelic therapy for depressive symptoms. 31:00 – On mystical experience see Walter Stace’s classic work, Mysticism and Philosophy. On the measurement of mystical-type experiences, see, e.g., Walter Pahnke’s paper here. 36:00 – On the idea of “psychoplastogens,” see here. 39:00 – See our earlier audio essay on placebo effects. 41:00 – For the study using Ritalin as an active placebo, see here.  44:00 – Michael Pollan’s book on psychedelics is here. 48:00 – On the idea of “idealism,” see here. 50:30 – For the 2021 study on psychedelics’ capacity to alter metaphysical beliefs, see here. 54:00 – For Dr. Letheby and collaborators’ paper about the “mysticism wars,” see here. 1:02:00 – For a popular article on the possibility that psychedelics reduce fear of death, see here. 1:03:00 – For Dr. Letheby’s paper on psychedelics and the fear of death, see here. 1:11:00 – The phrase “comforting delusion” comes from an article by Michael Pollan. 1:15:00 – For the “REBUS model,” see here. 1:20:00 – On the idea that psychedelics could serve as agents of moral enhancement, see the paper by Brian Earp here. 1:21:00 – For Dr. Letheby’s paper on psychedelics and environmental virtues, see here. For his paper on psychedelics and forgiveness, see here. 1:23:00 – On the subfield of “virtue ethics,” see here. On the virtue of “living in place,” see the paper by Nin Kirkham here. 1:28:00 – For the New Yorker article, by Matthew Hutson, on how psychedelics led him to see trees as smart, see here. For the study, led by Sandeep Nayak, on psychedelics leading people to expand their attributions of consciousness, see here. 1:32:00 – For a first paper by Dr. Letheby on the comparison between meditation and psychedelics, see here.   Recommendations Psychedelic Experience, Aidan Lyon Varieties of Psychedelic Experience, Robert Masters & Jean Houston The Antipodes of the Mind, Benny Shanon   Many Minds is a project of the Diverse Intelligences Summer Institute, which is made possible by a generous grant from the John Templeton Foundation to Indiana University. The show is hosted and produced by Kensy Cooperrider, with help from Assistant Producer Urte Laukaityte and with creative support from DISI Directors Erica Cartmill and Jacob Foster. Our artwork is by Ben Oldroyd. Our transcripts are created by Sarah Dopierala.   Subscribe to Many Minds on Apple, Stitcher, Spotify, Pocket Casts, Google Play, or wherever you listen to podcasts. You can also now subscribe to the Many Minds newsletter here! We welcome your comments, questions, and suggestions. Feel free to email us at: manymindspodcast@gmail.com.    For updates about the show, visit our website or follow us on Twitter (@ManyMindsPod) or Bluesky (@manymindspod.bsky.social).

We humans have a hard time becoming invisible. For better or worse, we're basically stuck with the skin and body we have; we’re pretty fixed in our color, our shape, our overall appearance. And so we're fascinated by creatures that aren't—creatures that morph to meet the moment, that can functionally disappear, that can shape-shift on a dime. And no creatures are more skilled, more astonishing, more bedazzling in their abilities to do this kind of thing than the cephalopods. But how do they do this exactly? What's going on in their skin? What's going on under their skin? And what's going on in their brains that makes this all possible? My guest today is Dr. Tessa Montague. Tessa is a neuroscientist in the Axel Lab at Columbia University; she studies the brain and behavior of the dwarf cuttlefish, with a special focus on the biology of their dynamic skin behaviors. Here, Tessa and I talk about how cuttlefish and other cephalopods exhibit the most impressive camouflaging abilities on the planet. We discuss how they change their skin's appearance with remarkable speed and fidelity—and not just when trying to blend in, but also when hunting, courting, fighting, and more. We talk about whether these behaviors are flexible and whether they're voluntary. We linger on the cruel irony that cuttlefish seem to be colorblind. We talk about the idea that a cephalopod's skin is kind of a window into their brain. We lay out the cells and organs in the cephalopod skin the make these behaviors possible—especially the tiny pigment-bearing structures called "chromatophores." And of course we also dive deep into the cephalopod brain and its sometimes bizarre and poorly understood structures. Excited to share it with you friends—I think you'll enjoy it. Without further ado, here's my chat with Dr. Tessa Montague.   A transcript of this episode is available here.   Notes and links 3:00 – For more on Dr. Montague’s recent expeditions to the Philippines, including photos, see here. 7:30 – Dr. Montague has published two recent reviews of dynamic skin behaviors in cephalopods—see here and here. We previously discussed cephalopod intelligence in a 2021 episode with Dr. Alex Schnell and a 2023 episode with the novelist Ray Nayler. 18:30 – For discussion of a recent “renaissance” in new model organisms, see here. 20:30 – For more on how chameleons change color, see this video. 25:00 – A video primer on cuttlefish camouflage, featuring the researcher Dr. Robert Hanlon. 30:30 – A recent paper on the details of pattern matching in cuttlefish camouflage. 31:00 – For more on the mimicking plant Boquila trifoliolata, see this popular article. See also our earlier episode with Dr. Paco Calvo and Dr. Natalie Lawrence. 35:00 – A video about the so-called mimic octopus.  40:00 – For the hypothesis about color discrimination via chromatic aberration and pupil shape, see here. 44:00 – For more on the “split body” skin behaviors observed in some cuttlefish, see here. 51:00 – For the David Attenborough clip about a cuttlefish hypnotizing a crab, see here. For the recent New York Times article on cuttlefish hunting behavior, including videos, see here. For the academic article that inspired the New York Times piece, see here. 58:00 – A recent scientific study on the possibility of octopus skin activity during dreaming. A video that helped popularize the idea of cephalopod skin activity as evidence of dreaming. Our earlier episode on why we—and other creatures—dream. 1:06:00 – For a study on chromatophore development from the lab of Dr. Gilles Laurent, see here. 1:11:00 – For more on papillae, including videos, see here.  1:17:00 – To explore an animated model of the cuttlefish brain, see this page of Dr. Montague’s website, Cuttlebase.   Recommendations Monarchs of the Sea, Danna Staaf Other Minds, Peter Godfrey-Smith Cephalopod Behavior, Roger Hanlon & John B. Messenger   Many Minds is a project of the Diverse Intelligences Summer Institute, which is made possible by a generous grant from the John Templeton Foundation to Indiana University. The show is hosted and produced by Kensy Cooperrider, with help from Assistant Producer Urte Laukaityte and with creative support from DISI Directors Erica Cartmill and Jacob Foster. Our artwork is by Ben Oldroyd. Our transcripts are created by Sarah Dopierala. Subscribe to Many Minds on Apple, Stitcher, Spotify, Pocket Casts, Google Play, or wherever you listen to podcasts. You can also now subscribe to the Many Minds newsletter here! We welcome your comments, questions, and suggestions. Feel free to email us at: manymindspodcast@gmail.com.    For updates about the show, visit our website or follow us on Twitter (@ManyMindsPod) or Bluesky (@manymindspod.bsky.social).

Kate Nave, a philosopher at the University of Edinburgh and author of *A Drive to Survive*, discusses the free energy principle and its evolution since its introduction. She explores its significant influence on cognitive science and its connection to concepts like cybernetics and predictive processing. The conversation highlights the relationship between life and cognition, questioning traditional views of intentionality and representation. Kate also critiques the principle, emphasizing the need to distinguish between various life processes.