'Many common ailments and physical conditions can influence the brain, leaving you depressed, anxious or slow-witted.' says Erich Kasten,professor of medical psychology at the University of Lbeck in Germany in an article that appeared in Scientific American on March 3, 2011.
According to Kasten, doctors often forget to ask patients about psychological symptoms. Conversely, psychologists and psychiatrists may treat mental troubles in isolation without looking for a physical cause. But now some doctors and psychologists are reviving the decades-old discipline of somatopsychology, which centers on the effects of physical illness on the brain.
'In Western culture people have long treated body and mind as separate. This dichotomy, popularized by French philosopher René Descartes in the 17th century, is still reflected in medical practice, as the specialists who look after our bodies remain different from those who attend to our psyches. Of course, the division has blurred in recent decades. We now know, after all, that the mind is housed in a physical entity, the brain, which is part of the body. And most people are also aware that psychological problems can produce physical symptoms in the form of psychosomatics; for instance, mental stress can spawn headaches, an upset stomach or even heart problems.
'But fewer people appreciate that the influence also runs in the other direction—that changes in your body can profoundly perturb your mental state,' he says.
Full article available at Scientific American website
This review by Dan Lloyd, Professor of philosophy at Trinity College, Connecticut on two new books on the embodied mind appeared in the American Scientist.
SUPERSIZING THE MIND: Embodiment, Action, and Cognitive Extension. Andy Clark. xxx + 286 pp. Oxford University Press, 2008.
OUT OF OUR HEADS: Why You Are Not Your Brain, and Other Lessons from the Biology of Consciousness. Alva Noë. xvi + 214 pp. Hill and Wang, 2009.
Sum res cogitans. “I am thinking substance.” With these words, written in about 1640, René Descartes simultaneously created the modern mind and gave it a huge philosophical headache. Cartesian dualism opened an abyss between mind and matter, which was good news for mechanistic physics. But “thinking substance” was thereby expelled from nature, and psychology has labored ever since to bring the mind back into the scientific fold—an effort that has culminated with the rise of cognitive neuroscience. A modern-day Descartes would perhaps say, “I am synaptic substance,” or, to be more accurate, “I am the information transmitted across neural networks.” Sum cerebrum.
Swapping brain for mind bridges the metaphysical gulf, but lesser dualisms still haunt cognitive science. The popular thought experiment of a “brain in a vat” captures the intuition that cognition and consciousness depend exclusively on the machinery between our ears. In the standard vat tale, one is asked to imagine that one’s brain has been removed from one’s body and placed in a vat of nutrient fluids, and that all of its normal neural inputs and outputs are being simulated by a supercomputer. The brain has no way of knowing whether it is in a skull or in a vat. Can we be sure that this is not our current situation? How do we know that anything beyond our brains is real rather than virtual? The moral of the thought experiment seems to be that the neural representations of body and world are only indirectly related to real external things. Is this state of affairs an anachronistic “Cartesian materialism,” with a neural computer on one side, and the body and world on the other?
A contemporary movement in cognitive science looks beyond this lingering dualism, promoting “extended cognition” and “embodiment” as crucial components of the science of mind. Andy Clark, author of Supersizing the Mind, and Alva Noë, author of Out of Our Heads, are preeminent expositors of extended and embodied cognition, and their two books represent the state of the movement, complete with its internal tensions.
Clark critiques what he calls the “brainbound” model, which depicts the mind “as essentially inner and, in our case, always and everywhere neurally realized.” He puts forth a contrasting model, which he refers to as EXTENDED, “according to which thinking and cognizing may (at times) depend directly and noninstrumentally upon the ongoing work of the body and/or the extraorganismic environment.” He further characterizes this model as follows:
According to EXTENDED, the actual local operations that realize certain forms of human cognizing include inextricable tangles of feedback, feed-forward, and feed-around loops: loops that promiscuously criss-cross the boundaries of brain, body, and world. The local mechanisms of mind, if this is correct, are not all in the head. Cognition leaks out into body and world.
The first section of Supersizing the Mind surveys work in which considerations of embodiment and extended informational resources have transformed theories of perception, cognition and motor control. Consider the problem of walking—easy for us, but a challenge for robots, especially if their walking is highly engineered via exact mechanical control of every joint, precalculated in a central controller. Such highly motorized and micromanaged movement is inefficient both physically and computationally. Biological walking, in contrast, exploits the “passive dynamics” of the material body. We ride on springy, free-swinging limbs. Once set in motion, animal bodies like ours saunter on their way with minimal shoving and shaping from the brain.
Our bodies lighten the load for our brains in many other ways as well. Expressive gestures, including words, Clark observes, are not merely communicative output but may also “function as part of the actual process of thinking.” Gestural information can interact with language. As we talk (to others and to ourselves), we also listen, using our bodies and words as reminders and abbreviations. Outsourcing is truly powerful, however, when we exploit the myriad cognitive scaffolds of the world around us, particularly the world of artifacts. In general, when information is available in the environment, we will use it instead of framing a “brainbound” thought. For example, to play the video game Tetris, one must anticipate whether moving shapes will fit together. To test for a match, one can manipulate the shapes mentally or try out the rotations on screen. Skilled players use on-screen manipulation rather than tax their minds.
The picture of mind that emerges in Clark’s treatment, although not “brainbound,” remains neurocentric. He portrays the brain as a lazy genius at the center of a loose confederacy of tricks and tweaks. Some of the outsourcing involves symbol manipulation and some involves shortcuts that eliminate the need for language (or other symbols) altogether. Clark’s vision loosens up cognitive science itself: Good old-fashioned computational models still have a place, albeit a diminished one. We need to be alert to every kind of computation (including dynamical systems of distributed representations) and, more important, to the diversity of vehicles for computation, many of which are outside the head.
One consequence of the extended approach is a “hypothesis of cognitive impartiality”:
Our problem-solving performances take shape according to some cost function or functions that, in the typical course of events, accord no special status or privilege to specific types of operation (motoric, perceptual, introspective) or modes of encoding (in the head or in the world).
Cognition doesn’t care how or where it occurs! Extended theorizing in the spirit of this hypothesis could reshape cognitive science, embedding embodied human life in an ecology of useful and symbolic objects, a flow in which neural activity is one eddy among many.
Extended cognition entails a supersized mind, and much of the second part of Clark’s book defends the philosophical idea that mind itself leaks into the world. The core argument is really “Well, why not?” Worldly activity with cognitive scaffolding accomplishes many of the same ends as neural computation and evidently saves the brain a lot of bother, so why not let the mind be where the work is done? In particular, philosophical views about beliefs, regarding both what they are and how they fit in the life of the mind, seem neutral about where a belief is located. It might be spread among the synapses, or on a microchip hardwired into the brain, or in a handy notebook—any of those media could preserve all the features of the belief. Critics search for some “mark of the mental” that will keep thinking inside the skull, but Clark counters that in some cases these lines in the sand are the result of mistaken analyses of the mental, and in other instances, they are lines easily crossed by extended minds.
Alva Noë’s target is consciousness, and in broad terms his position is compatible with Clark’s. Noë writes that in Out of Our Heads his central claim is that to understand consciousness—the fact that we think and feel and that a world shows up for us—we need to look at a larger system of which the brain is only one element. Consciousness is not something the brain achieves on its own. Consciousness requires the joint operation of brain, body, and world. Indeed, consciousness is an achievement of the whole animal in its environmental context. I deny, in short, that you are your brain.
Even in this passage we see an ambiguity that runs throughout the book. (Unlike Noë’s thoughtful and thorough Action in Perception [The MIT Press, 2004], Out of Our Heads is a manifesto of hyperbolic claims resting on sketches of argument.) Is it that we are not merely our brains (which is Clark’s view as well), or that we are not our brains at all? How completely “out of our heads” are we? The radical possibility runs through passages like this one, in which Noë describes what he refers to as a “sensorimotor, enactive, or actionist approach”:
Seeing is not something that happens in us. It is not something that happens to us or in our brains. It is something we do. It is an activity of exploring the world making use of our practical familiarity with the ways in which our own movement drives and modulates our sensory encounter with the world. Seeing is a kind of skillful activity.
This theory of perception has strong echoes of J. J. Gibson’s “ecological approach” to perception, along with the embodied phenomenology of Maurice Merleau-Ponty. Seeing is certainly skillful activity, but is that activity mediated by anything like an inner representation, or by a state of conscious awareness that either guides the activity or results from it? Noë repeatedly edges toward elimination of inner states, only to hedge:
We ourselves are distributed, dynamically spread-out, world-involving beings. We are not world representers. We have no need for that idea. To put the point in a provocative way, we are, in Merleau-Ponty’s memorable phrase, “empty heads turned toward the world.” And as a result of this, our worlds are not confined to what is inside us, memorized, represented. Much more is present to us than is immediately present. We live in extended worlds where much is present virtually, thanks to our skills and to technology.
We have no need for representation—at all? Or is it that our worlds are not confined to what is inside us, those innards nonetheless enacting cognitive, computational and conscious processes?
There is much to be gained by recognizing the intricate embedding of consciousness in the body and the world. Cognitive science (including the study of consciousness) has been shackling itself with its brainbound assumptions. Consciousness depends on its embodied embedding, but should it be identified entirely with the myriad couplings and loops the brain surely exploits?
This question is in play between Clark and Noë. Each disputes the other in passing. For Clark, one of the distinctive features of conscious awareness is the capacity to disengage from enacted specifics. Driving a car, for example, requires precise enactive sensorimotor coupling for beginners and experts alike, but for the practiced driver the details drop out of awareness. Noë’s view identifies consciousness with all the activities of the extended mind and thus implies that skilled enactors remain aware of everything engaged by their performance.
Clark also enlists clever experiments and reports of brain deficits that suggest a dissociation of awareness from sensorimotor knowledge. Familiar optical illusions make objects that are in fact identical look as though they differ in size, but when one reaches to grasp them, one’s fingers open to the same (correct) extent regardless of context. The eye-to-hand loop is not fooled by appearances, however things may seem to the conscious mind. Similarly, some brain lesions can impair the ability to describe a scene while sparing the capacity for fluent sensorimotor interaction, whereas other lesions have the opposite result. Thus there seem to be two partially distinct systems, one mediating fluent behavior and the other generating the model of the world available to consciousness.
From Noë’s point of view, to supersize the mind while leaving consciousness inside the head seems arbitrary, if not fainthearted. Any such distinction regards one fantastically complex information processing system as conscious, while declaring another, equally complex system, not. What’s the difference?
An expansive, totalized theory of consciousness like Noë’s solves the problem by dissolving it:
The problem of consciousness, then, is none other than the problem of life. What we need to understand is how life emerges in the natural world.
Descartes framed the modern mind with a sentence beginning “I am . . . ,” launching centuries of debate about how to complete the thought. But until now, that first-person grammatical form has been the eye of the storm, a nexus of subjectivity to which a world appears. In a truly post-Cartesian world of looping, evanescent, chattering, clattering networks, the problem of consciousness may simply disappear. The sum may turn out to be less than the whole of its parts.
Dan Lloyd is the Thomas C. Brownell Professor of Philosophy at Trinity College, Connecticut. He is the author of Radiant Cool: A Novel Theory of Consciousness (The MIT Press, 2004) and is currently working on a book-length philosophical dialogue titled Ghosts in the Machine.
The article below celebrates the birth of South African philosopher Marthinus Versfeld one hundred years ago. It appeared in Die Burger of 10 Augustus 2009 and is written by Prof Anton Van Niekerk head of the department of philosophy and director of the Centre for Applied Ethics at the University of Stellenbosch, South Africa.
In the article Van Niekerk notes that Versfeld himself stated that his entire intellectual life was a reaction to the mind-body duality of Descartes. For Versfeld everything in nature was infused with spirit. True spirituality, he said, doesn’t require a rejection of everything to do with the body. Rather it is about discovering the extraordinary in ordinary things - a flower, a sunset, community and definitely good food and wine.
Van Niekerk writes that according to Versfeld, ones spiritual life is therefore not about ideas, philosophy or even ones prayer life. He who looks after the small, everyday things will discover in these things, eternity and the joy of the creation and the creator.
To speak about a person’s spirituality is to speak about his embodied being – the way he walks, the way he blows his nose, the way he looks after his dog and his garden. And also the way he eats.
Versfeld’s book Food for Thought, Van Niekerk feels, testifies to the philosophy that humans are what they eat.The food that we eat builds the body and therefore the soul indicating our state of embodiment.
(My summary and interpretation)
Die volheid van sy lewe
Artikel deur Prof Anton van Niekerk, dosent in en voorsitter van die departement filosofie en direkteur van die Sentrum vir Toegepaste Etiek aan die Universiteit van Stellenbosch.
Marthinus Versfeld is vandag presies 100 jaar gelede, op 11 Augustus 1909, gebore. Gedurende sy leeftyd, en nog steeds, was en bly hy een van Suid-Afrika se bekendste filosowe.
Die katalogus van die J.S. Gericke-biblioteek in Stellenbosch dui 17 boeke van hom aan (daar is waarskynlik meer), waarvan die meeste in Afrikaans geskryf is, ten spyte van die feit dat hy vir sy hele professionele lewe professor aan die Universiteit van Kaapstad was.
Die begrip “filosoof” ontgin egter nie naastenby die spektrum van beskrywings wat ewe goed op hom gepas het nie: Afrikaner, Christen, Rooms-Katoliek, kenner en bewonderaar van die Oosterse mistiek, natuurliefhebber en -kenner, tuinier, en, les bes, bobaas kok.
Die mens Versfeld is ’n mengsel van komponente wat, in kombinasie, so onwaarskynlik, maar ook so verrassend lyk soos sommige van die disse waaroor hy met soveel entoesiasme geskryf het.
Dit is ’n onbegonne taak om in hierdie beperkte ruimte reg te laat geskied aan die rykdom van idees wat in sy werke na vore kom.
Een deurlopende tema verdien egter spesiale vermelding.
Dit is sy insigtelike waardering van die feit dat die onderskeiding tussen goed en kwaad nie saamval met die onderskeid tussen materie en gees, of tussen liggaamlikheid en spiritualiteit nie.
Die verskil tussen ’n goeie en ’n slegte mens lê nie in die feit dat die een meer sensueel ingestel is of meer goed het as die ander nie.
Die slegte mens is egter die een wat nie sy goed besit nie, maar deur sy goed besit word, en daarom nie in staat is om ’n broodkorsie met sy mede- mens te deel nie.
Die goeie mens daarenteen loop, omdat hy ’n pelgrim is, altyd gevaar om sy goed te verloor – en, paradoksaal genoeg, besit hy daarom sy goed op ’n meer betroubare manier as die slegte mens.
Wie sy lewe, en sy goed, ten alle koste wil behou, sal dit verloor, en wie bereid is om sy lewe te verloor, sal dit red, of liewer, sal gered word.
Een van Versfeld se belangrikste insigte was in die aard van spiritualiteit.
Hy skryf dat sy ganse intellektuele lewe opgegaan het in ’n verset teen Descartes, die denker wat ons wou wysmaak dat liggaam en siel, gees en materie, skeibaar is.
Vir Versfeld, daarenteen, is die ganse natuur deurspek met gees.
Hy het ons bewus gemaak van die geestelikheid van klippe, berge en bome.
Ware spiritualiteit beteken nie om af te sien of weg te draai van alles wat liggaamlik en aards is nie.
Een van die min “suiwer geeste” waarvan ons weet, is immers die duiwel self.
Ware spiritualiteit beteken om die ongewone te ontdek in die gewone, om genade raak te sien in ’n lenteblom of ’n sonsondergang, om onderlinge gemeenskap te beleef in die genieting van goeie kos, om die persoon van Christus te ontdek in die konkrete, aardse tekens van brood en wyn.
’n Mens se geestelike lewe, skryf Versfeld, is daarom nie in die eerste plek hoe jy idealiseer, filosofeer of gestemd is in jou gebedslewe nie.
Om oor ’n mens se gees te praat, is om oor die volheid van sy lewe te praat, hoe hy loop, hoe hy sy neus blaas, hoe hy omsien na sy hond en sy tuin.
Hy wat getrou is in die klein, alledaagse dinge, ontdek in hierdie dinge die ewigheid en die vreugde van die skepping en die skepper.
Vir my bly Food for thought, Versfeld se “kookboek van ’n filosoof” steeds een van sy boeiendste geskrifte.
Die mens is wat hy eet.
Kosmaak is nie slegs die produk van idees nie, maar reflekteer idees en produseer idees.
Die kos wat ons eet, vorm die liggaam, en daarom die siel. Dat ons moet eet, is die tasbaarste herinnering aan hoe radikaal aards, liggaamlik en potensieel genotvol ons lewe in die wêreld is.
Kos verraai daarby ’n mens se herkoms en skep jou omgewing.
’n Plek soos Kaapstad, Versfeld se tuiste, dank volgens hom sy ontstaan aan niks minder nie as groente en sop.
Die Kaap as woonplek het immers tot stand gekom vanweë die Hollanders se stigting van ’n verversingspos ten einde te voorkom dat hul matrose op die lang seevaarte na die Ooste skeurbuik kry.
Maar belangriker: Ons skep ’n omgewing, ’n gehumaniseerde omgewing, deur die produksie van kos.
’n Mens hoef net ’n rit deur die Bolandse distrikte te onderneem om onder die indruk te kom van hoe die voorkoms van die wêreld waarin ons leef, beïnvloed is deur en vanweë die produksie van kos karakter kry.
Die Bolandse landskap is immers een van wingerde en boorde, soos die Mediterreense landskap geskep word deur olyfbome en die Ceylon-landskap deur teeplantasies.
Maar ons bou ook paaie, ontwikkel skeepsroetes, ontwerp voertuie, bou fabrieke en produseer voorwerpe ter wille van die voorbereiding en genieting van ’n goeie maaltyd.
Ons mag Versfeld en sy werk nie vergeet nie.
By min ander mense kon ons die ruimheid, die buigsaamheid om van ander te leer en daardeur verander te word, beter leer as by hom.
Ek het die voorreg gehad om sy begrafnis in 1995 te kon bywoon; seker die mees onkonvensionele “uitvaart” wat ek tot nog toe meegemaak het.
Op die eenvoudige touhandvatselkis was ’n pampoen en veldblomme.
Die diens was in Mowbray se Katolieke kerk; wierook het gebrand, en Boeddhistiese inkantasies was net soveel deel van die gebeure as die eucharistie.
Dis is die soort mens en die soort ruimheid wat ons sal kan laat oorleef in hierdie land.
How you answer questions like these, it turns out, may determine how long it will take for you to decipher what you're reading, solve your puzzle, or get your keys back.
The brain is often envisioned as something like a computer, and the body as its all-purpose tool. But a growing body of new research suggests that something more collaborative is going on - that we think not just with our brains, but with our bodies. A series of studies, the latest published in November, has shown that children can solve math problems better if they are told to use their hands while thinking. Another recent study suggested that stage actors remember their lines better when they are moving. And in one study published last year, subjects asked to move their eyes in a specific pattern while puzzling through a brainteaser were twice as likely to solve it.
The term most often used to describe this new model of mind is "embodied cognition," and its champions believe it will open up entire new avenues for understanding - and enhancing - the abilities of the human mind. Some educators see in it a new paradigm for teaching children, one that privileges movement and simulation over reading, writing, and reciting. Specialists in rehabilitative medicine could potentially use the emerging findings to help patients recover lost skills after a stroke or other brain injury. The greatest impact, however, has been in the field of neuroscience itself, where embodied cognition threatens age-old distinctions - not only between brain and body, but between perceiving and thinking, thinking and acting, even between reason and instinct - on which the traditional idea of the mind has been built.
"It's a revolutionary idea," says Shaun Gallagher, the director of the cognitive science program at the University of Central Florida. "In the embodied view, if you're going to explain cognition it's not enough just to look inside the brain. In any particular instance, what's going on inside the brain in large part may depend on what's going on in the body as a whole, and how that body is situated in its environment."
The emerging field builds on decades of research into human movement and gesture. Much of the earlier work looked at the role of gestures in communication, asking whether gesture grew out of speech or exploring why people gestured when they were talking on the telephone.
But today, neuroscientists, linguists, and philosophers are making much bolder claims. A few argue that human characteristics like empathy, or concepts like time and space, or even the deep structure of language and some of the most profound principles of mathematics, can ultimately be traced to the idiosyncrasies of the human body. If we didn't walk upright, for example, or weren't warm-blooded, they argue, we might understand these concepts totally differently. The experience of having a body, they argue, is intimately tied to our intelligence.
"If you want to teach a computer to play chess, or if you want to design a search engine, the old model is OK," says Rolf Pfeifer, director of the artificial intelligence lab at the University of Zurich, "but if you're interested in understanding real intelligence, you have to deal with the body."
Embodied cognition upends several centuries of thinking about thinking. Rene Descartes, living in an age when steam engines were novelty items, envisioned the brain as a pump that moved "animating fluid" through the body - head-shrinkers through the ages have tended to enlist the high-tech of their day to describe the human cognitive system - but the mind, Descartes argued, was something else entirely, an incorporeal entity that interacted with the body through the pineal gland.
While a few thinkers, most notably the French philosopher Maurice Merleau-Ponty in the 1940s, challenged Descartes' mind-body separation, it remained the dominant model up through the 20th century, though its form evolved with the times. After the development of the modern computer in the years after World War II, a new version of the same model was adopted, with the brain as a computer and the mind as the software that ran on it.
In the 1980s, however, a group of scholars began to contest this approach. Fueled in part by broad disappointment with artificial-intelligence research, they argued that human beings don't really process information the way computers do, by manipulating abstract symbols using formal rules. In 1995, a major biological discovery brought even more enthusiasm to the field. Scientists in Italy discovered "mirror neurons" that respond when we see someone else performing an action - or even when we hear an action described - as if we ourselves were performing the action. By simultaneously playing a role in both acting and thinking, mirror neurons suggested that the two might not be so separate after all.
"You were seeing the same system, namely the motor system, playing a role in communication and cognition," says Arthur Glenberg, a professor of psychology and head of the embodied cognition laboratory at ArizonaStateUniversity.
This realization has driven much of the recent work looking at how moving and thinking inform and interfere with each other. For example, a pair of studies published in 2006 by Sian Beilock, now an assistant professor of psychology at the University of Chicago, and Lauren Holt, one of her former students, examined how people who were good at certain physical activities thought about those activities.
In one study, Beilock and Holt had college hockey players, along with a non-hockey-player control group, read a sentence, sometimes hockey-related, sometimes not. Then the subjects would be shown a picture and asked if it corresponded with the sentence. Hockey players and non-hockey players alike almost invariably answered correctly, but on the hockey-related sentences the response times of the hockey players were significantly faster than the non-players. In a second study, the researchers found similar results with football players. According to Beilock, the difference in response time wasn't a matter of knowledge - after all, all of the subjects in the study got the vast majority of the questions right. What it suggested, Beilock argues, is that the athletes' greater store of appropriate physical experiences served as a sort of mental shortcut.
"People with different types of motor experiences think in different ways," she argues.
These sorts of results aren't simply limited to thinking about sports, or other highly physical activities.
A 2003 study by Michael Spivey, a psychology professor at Cornell, and his student Elizabeth Grant, found that people who were given a tricky spatial relations brainteaser exhibited a distinctive and unconscious pattern of eye movements just before they arrived at the answer. The subjects seemed to unconsciously work through the problem by enacting possible solutions with their gaze.
A study published in August by Alejandro Lleras and Laura Thomas, two psychologists at the University of Illinois, built on those results by inducing the eye movements Spivey had discovered. Lleras and Thomas found that doing so greatly improved the rate at which people solved the problem - even though most never figured out that the eye movements had anything to do with it.
"The subjects actually think that the eye-tracking task is very distracting," Lleras says. "They think we're doing this to keep them from solving the problem."
Other studies have looked at non-spatial problems and at memory. Work led by Susan Goldin-Meadow, a psychology professor at the University of Chicago, has found that children given arithmetic problems that normally would be too difficult for them are more likely to get the right answer if they're told to gesture while thinking. And studies by Helga Noice, a psychologist at ElmhurstCollege, and her husband Tony Noice, an actor and director, found that actors have an easier time remembering lines their characters utter while gesturing, or simply moving.
The body, it appears, can subtly shape people's preferences. A study led by John Cacioppo, director of the Center for Cognitive and Social Neuroscience at the University of Chicago, found that subjects (all non-Chinese speakers) shown a series of Chinese ideographs while either pushing down or pulling up on a table in front of them will say they prefer the ideographs they saw when pulling upward over the ones they saw while pushing downward. Work by Beilock and Holt found that expert typists, when shown pairs of two-letter combinations and told to pick their favorite, tend to pick the pairs that are easier to type - without being able to explain why they did so.
What's particularly interesting to neuroscientists is the role that movement seems to play even in abstract thinking. Glenberg has done multiple studies looking at the effect of arm movements on language comprehension. In Glenberg's work, subjects were asked to determine whether a string of words on a computer screen made sense. To answer they had to reach toward themselves or away from themselves to press a button.
What Glenberg has found is that subjects are quicker to answer correctly if the motion in the sentence matches the motion they must make to respond. If the sentence is, for example, "Andy delivered the pizza to you," the subject is quicker to discern the meaning of the sentence if he has to reach toward himself to respond than if he has to reach away. The results are the same if the sentence doesn't describe physical movement at all, but more metaphorical interactions, such as "Liz told you the story," or "Anne delegates the responsibilities to you."
The implication, Glenberg argues, is that "we are really understanding this language, even when it's more abstract, in terms of bodily action."
Some linguists, cognitive scientists, and philosophers go further - arguing that the roots of even the most complex and esoteric aspects of human thought lie in the body. The linguist George Lakoff, of the University of California, Berkeley, along with Rafael Nunez, a cognitive scientist at the University of California, San Diego, have for several years advanced the argument that much of mathematics, from set theory to trigonometry to the concept of infinity, derives not from immutable properties of the universe but from the evolutionary history of the human brain and body. Our number system, they argue, and our understanding of addition and subtraction emerge from the fact that we are bipedal animals that measure off distances in discrete steps.
"If we had wheels, or moved along the ground on our bellies like snakes," Lakoff argues, "math might be very different."
These ideas have met intense opposition among mathematicians, but also among some cognitive scientists, who believe they reflect an overreaching reading of a promising but still sketchy set of experimental results.
"I think these findings are really fantastic and it's clear that there's a lot of connection between mind and body," says Arthur Markman, a professor of psychology at the University of Texas. He remains skeptical, though, that the roots of higher cognition will be found in something as basic as the way we walk or move our eyes or arms.
"Any time there's a fad in science there's a tendency to say, 'It's all because of this,"' Markman says. "But the thing in psychology is that it's not all anything, otherwise we'd be done figuring it out already."
While embodied cognition remains a young field, some specialists believe that it suggests a rethinking of how we approach education. Angeline Lillard, a psychology professor at the University of Virginia, says that one possibility is to take another look at the educational approach that Italian educator Maria Montessori laid out nearly 100 years ago, theories that for decades were ignored by mainstream educators. A key to the Montessori method is the idea that children learn best in a dynamic environment full of motion and the manipulation of physical objects. In Montessori schools, children learn the alphabet by tracing sandpaper letters, they learn math using blocks and cubes, they learn grammar by acting out sentences read to them.
To Lillard, the value of embodied cognition in education is self-evident.
"Our brains evolved to help us function in a dynamic environment, to move through it and find food and escape predators," she says. "It didn't evolve to help us sit in a chair in a classroom and listen to someone and regurgitate information."
