{"version":1,"type":"rich","provider_name":"Libsyn","provider_url":"https:\/\/www.libsyn.com","height":90,"width":600,"title":"The inner life of the hand","description":"Newton saw in the human hand proof of the divine; Darwin saw a key to our species' success. Many others, too, have described the hand in hyperbolic terms, as a paragon of design, a cornerstone of human uniqueness, an engine of our achievements. But what makes the human hand so powerful? Is it the proportions of the fingers? Is it the opposability of the thumb? Or, could it be none of this? Could it be that the real power of our hands lies\u2014not in the physical design\u2014but elsewhere, out of sight?  My guest today is Dr. Matt Longo. Matt is Professor of Cognitive Neuroscience at Birkbeck, University of London. He's the author of the recent book, The Invisible Hand, a wide-ranging tour of the human hand and how it's geared into the brain. Here, Matt and I talk about the difference between the "visible hand"\u2014that is, its physical structure\u2014and the "invisible hand"\u2014its representation in the brain. We consider the evolution of the visible hand and whether there really is anything truly distinctive or impressive about it. We talk about the biology of touch. We tour the invisible hand, discussing how\u2014through cortical magnification\u2014the hand becomes over-represented in the brain's sensory maps. We catalogue a fews ways that the hands can go awry. And we talk about whether we should feel any nostalgia for all the hand-based activities and crafts that we're losing. Along the way, we also touch on star-nosed moles and raccoons; tetrapods and the primitive archetype; hand dominance; the parallel between a horse's knee and a human's wrist; tool use, plasticity and abstraction; homunculi; the rubber-hand illusion; supernumerary fingers; the Third Thumb project; and the question of what it might unlock if dolphins had hands. Alright, friends, this is a fun one. On to my interview with Dr. Matt Longo!   Notes 3:00 \u2013 For discussion of the many traits and behaviors that have been proposed as uniquely human, see our earlier audio essay.  5:00 \u2013 For an example of the \u201cif only dolphins had hands\u201d thought experiment, see here. 8:00 \u2013 See The Principles of Anatomy as Seen in the Hand by Frederic Wood Jones. 10:30 \u2013 Dr. Longo\u2019s book, The Invisible Hand, is available open access here.  16:00 \u2013 For discussion of how\u2014in horses and other species\u2014the five digits have been reduced or otherwise tweaked over evolution, see here. For an image showing examples of homology between the human forelimb and the forelimbs of other creatures, see here. 19:00 \u2013 For a brief discussion of \u201cthumb opposability\u201d see here. For an influential discussion of hand morphology and human hand grips, see work by Mary Marzke here. 30:00 \u2013 For our earlier episode on the brain\u2019s many maps, see here. 34:00 \u2013 For a discussion of Penfield\u2019s work and the idea of a \u201chomunculus\u201d in the brain, see here.  42:00 \u2013 For an illustration of a \u201chomunculus\u201d with big lips and hands, see here.  44:30 \u2013 For more on the star-nosed mole and its distinctive appendage, see here. 49:00 \u2013 For the report that first coined the term \u201cnumbsense,\u201d see here. For recent work on \u201canarchic hand,\u201d see here. For more on phantom limbs, see here. For a classic study of the \u201crubber hand illusion\u201d see here.  59:30 \u2013 For a discussion of hand-dominance across primate species, see here. 1:03:00 \u2013 More on the \u201cThird Thumb\u201d project.  1:06:00 \u2013 A classic case of \u201cmotor equivalance\u201d is seen in handwriting.   Recommendations Marco Catani, \u2018A little man of some importance\u2019 Tracy Kivell, \u2018Evidence in hand: Recent discoveries and the early evolution of human manual manipulation\u2019 Hands, by John Napier   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. 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 Bluesky (@manymindspod.bsky.social). ","author_name":"Many Minds","author_url":"https:\/\/disi.org\/manyminds\/","html":"