damasio minding the body

We spend a good part of our lives at-tending to the sights and sounds of theworld outside of us, oblivious to the fact that we (mentally speaking) exist in our bodies, and that our bodies existin our minds.1 This neglect is both goodand bad: good when it allows us to letour own physical suffering go undetect-ed, bad when it screens us from the bio-logical roots of our selves. Be that as itmay, the body does come to mind, in nouncertain terms, when injury or diseasebreaks down its integrity and causes

pain. The body also comes to mind,somewhat less demandingly, in mo-ments of joy, when physical lightnessand ease of function inevitably make us aware of the body.

What we would like to address in thisessay, however, is not the obvious factthat the state of our bodies can be con-veyed to our minds, but rather the neu-rological mechanisms that enable thisspectacular phenomenon. How can thebody, with its myriad physical compart-ments and complicated operations,show up in our minds and be felt?

The most common perspective on this question assumes that there is a‘mind-body problem,’ which is best re-solved using the tools of analytic philos-ophy. Our perspective here, however, ismore restricted, focusing instead on thebiological scaffolding without which thebody certainly cannot be present in themind. We are convinced, incidentally,that this perspective and its facts are rel-evant to the mind-body problem and goa long way toward solving it. Elsewherewe have addressed the connection,2 but

Dædalus Summer 2006 15

Antonio Damasio & Hanna Damasio

Minding the body

Antonio Damasio, a Fellow of the AmericanAcademy since 1997, is David Dornsife Professorof Neuroscience and director of the Brain andCreativity Institute at the University of SouthernCalifornia. He is the author of “Descartes’ Error”(1994), “The Feeling of What Happens” (1999),and “Looking for Spinoza” (2003).

Hanna Damasio, a Fellow of the AmericanAcademy since 1997, is Dana Dornsife Professorof Neuroscience and director of the Dornsife Cog-nitive Neuroscience Imaging Center at the Univer-sity of Southern California. She is the author of“Lesion Analysis in Neuropsychology” (1989)and “Human Brain Anatomy in ComputerizedImages” (1995), the new edition of which waspublished in 2005.

© 2006 by the American Academy of Arts & Sciences

1 The work discussed in this essay has beensupported by a grant from The Mathers Foun-dation.

2 See Antonio Damasio, The Feeling of WhatHappens (New York: Harcourt, 1999), for anoverview of the argument.

here we simply wish to discuss the latestin the nuts and bolts of how the bodycomes to mind.

In attempting to answer this question,we will use, as a stepping stone, the sameassumptions William James made whenhe tried to explain how we perceive ouremotions, a process he thought requireda mental representation of the body:perceptions, any perception, occur in the brain; and perceptions of the bodyinclude, of necessity, brain processesthat depend on a particular object–thebody-proper.

James, along with a host of contempo-rary physiologists, already knew for afact that there were nerve pathways con-ducting impulses from the body to thebrain. He also had an inkling, given thethen-emerging evidence for brain spe-cialization, that the parts of the brainrelated to bodily perception would bedistinct from those linked to visual orauditory perceptions. Today, we have no reason to doubt James’s conjecture,and plenty of evidence to show that hisaccount is fundamentally correct.

We have, however, many new devel-opments to report on this score.3 First,we now know that the details of James’sbasic arrangement are far more intricatethan what might have been imagined acentury ago. For example, the body useschemical signals as well as neural signalsto communicate with the brain; and therange of information conveyed to thebrain is wider than expected, from theconcentration of chemical molecules tothe contractions of muscles anywhere inthe body.

Second, while the brain does repre-sent, with ½delity, body states that areactually occurring, it can do far more

than that: it can also modify the repre-sentation of an ongoing state, and, mostdramatically, it can simulate body statesbefore they occur or body states that donot occur at all.

Third, the new knowledge has pro-found implications for our understand-ing of consciousness and of social behav-ior.

In what follows, we will address eachof these developments in order.

Let us begin by clarifying that when-ever we use the term ‘body,’ we mean‘body-proper,’ so as to leave aside thebrain. The brain is also a part of thebody, of course, but it happens to have a particular status: it is the part of thebody toward which every other bodypart is communicating, and that cancommunicate to every other part.

Misconceptions abound regardinghow the body talks to the brain. Forinstance, those who are unacquaintedwith neuroscience (and, regrettably,some who are) assume incorrectly thatthe body operates as a single unit, a lump of flesh connected to the brain by live wires called nerves. Many alsomistakenly believe that the main com-munication occurs between the body’sorgans–the viscera–and the brain, viathe autonomic nervous system. Anoth-er erroneous belief is that the body-brain communication goes one way,from body to brain, but not in the re-verse direction.

The reality is quite different.First, rather than being one unit, the

body has numerous separate compart-ments. To be sure, the viscera to whichso much attention is paid–the heart, thelungs, the gut, the mouth, the tongue,the throat, and the equally vital but lessrecognized organ, the skin, which envel-ops our entire organism–are essential,but all of the body’s compartments are

16 Dædalus Summer 2006

AntonioDamasio & HannaDamasio on body in mind

3 See Antonio Damasio, Looking for Spinoza(New York: Harcourt, 2003), for an overview.

indispensable for its normal operation.And the communication between vis-cera and brain is not con½ned to the au-tonomic nervous system. There are oth-er neural channels. This communicationis not even con½ned to nerves alone:there is a chemical channel as well.

The chemical bath in which all bodycells live and of which the blood is anexpression–the internal milieu–alsoends up sending signals to the brain, not via nerves but via chemical mole-cules, which impinge directly on cer-tain parts of the brain designed to re-ceive their messages. The range of in-formation conveyed to the brain in thismanner is extremely wide. It includes,for example, the state of contraction ordilation of smooth muscles (the musclesthat form the walls of the arteries, thegut, and the bronchi); the amount of ox-ygen and carbon dioxide concentratedlocally in any region of the body; thetemperature and the pH at various loca-tions; the local presence of toxic chemi-cal molecules; and so forth.

There is more to the body, however,than viscera and internal milieu. Thereare also striated muscles. When thesemuscles are connected to two bonesarticulated by a joint, the shortening of these muscles generates movement.Picking up an object, walking, talking,breathing, and eating are all actions that depend on muscular contraction.But note that whenever those contrac-tions occur, the con½guration of thebody changes: except for moments ofcomplete immobility, the image of thebody in space is changing continuously.

The secret behind the changes is sim-ple. In order to control movement withprecision, the body must instantly con-vey information on the state of everystriated muscle to the brain, using ef½-cient nerve pathways, which are evolu-tionarily more modern than those that

convey signals from the viscera and in-ternal milieu. These pathways arrive inbrain regions dedicated to sensing thestate of these muscles. (The only partialexception to this scheme of things has todo with the heart, which is also made ofstriated muscles, and whose contrac-tions serve to pump blood, but whosesignals are segregated to brain sites dedi-cated to the viscera.)

However, just as important as thebody-to-brain inputs described above is the fact that the brain also sends mes-sages to the body. This fact is often for-gotten. While body states are being con-tinuously mapped in the brain, many as-pects of those body states were causedby brain signals to the body in the ½rstplace. Just as with the communicationfrom the body to the brain, the braincommunicates with the body via neuralchannels–nerves whose messages leadto the contraction of muscles and theexecution of actions–and via chemicalchannels. Examples of the latter includehormones, such as cortisol, testosterone,or estrogen. The release of hormones re-sults in different modes of operation forthe internal milieu and the viscera.

The idea here is that the body andbrain are engaged in a continuous inter-action that unfolds in time, within dif-ferent regions of the body and withinmental space as well. Mental states causebrain states, which cause body states;body states are then mapped in the brainand incorporated into the ongoing men-tal states. A small change on the brainside of the system can have major conse-quences for the body state (think of therelease of a hormone); likewise, a smallchange on the body side (think of a knifecut, or a tooth infection, or the ruptureof an ulcer) can have a major effect onthe mind once the change is mapped as anociceptive state and perceived as acutepain.


Minding the body

Curiously, German and British physi-ologists described the outlines of thisbasic arrangement over a century ago,but its importance for the understand-ing of both neurobiology and cognitivescience was largely ignored until recent-ly. And its intricate neuroanatomical and neurophysiological details have onlybeen uncovered in the past few years.4

Those details reveal that the state ofthe body’s interior is conveyed via neu-ral channels dedicated to speci½c brainregions. Speci½c nerve-½ber types–C-½bers–bring signals from every nookand cranny of the body into speci½cparts of the central nervous system, such as the lamina-I section of the pos-terior horn of the spinal cord, at everylevel of its length, or the pars caudalis of the trigeminal nerve. The brain re-gions charged with handling the signalsas they march toward the higher levelsof the brain are also speci½c. Togetherwith chemical information available inthe bloodstream, these messages con-vey to the brain the state of a good partof the body’s interior–all the visceral/chemical body components beneath theskin’s outer perimeter. Complementingthis interior sense, or interoception, isinformation regarding the state of striat-ed muscles anywhere in the body. Mes-sages from the striated muscles use dif-ferent kinds of nerve ½bers and differentstations of the central nervous system all the way into the higher levels of thebrain. The upshot of all this signaling is a multidimensional picture of the bodyin the brain and in the mind.

That the body, in most of its aspects, iscontinuously represented in the brain is

thus a well-proven fact. The organismrequires that sort of ongoing represen-tation for rather transparent reasons: inorder for the brain to coordinate physio-logical states in the body-proper, whichit does without our being consciouslyaware of what is going on, the brainmust be informed about the variousphysiological parameters at differentregions of the body. The informationmust be faithful and current if it is topermit optimal controlling responses:call this information-processing net-work the ‘body loop.’

But this is not the only network thatlinks mind and body–there is anotherwe call the ‘as-if body loop.’ Some ½f-teen years ago, Antonio proposed that in certain circumstances, as an emotionunfolds, the brain rapidly constructsmaps of the body comparable to thosethat would result were the body actual-ly changed by that emotion. The con-struction can occur well ahead of theemotional change, or even instead ofthe change. In other words, the brain can simulate a certain body state as ifit were occurring; and because our per-ception of any body state is rooted in the body maps of the somatosensing re-gions, we perceive the body state as ac-tually occurring even if it is not. (Thisfunctional arrangement can work foremotion because there is no need for½delity of information concerning thebody states that de½ne an emotion pro-vided the kind of emotion in questioncan be detected without ambiguity.)

At the time the ‘as-if body loop’hypothesis was ½rst advanced, the evi-dence we could muster in its favor wascircumstantial. First, it made sense forthe brain to know about the body state it was about to produce. The advantagesof this sort of ‘advance simulation’ wereobvious in the phenomenon of ‘efferenz-copie.’ Efferenz-copie is what allows



4 A. D. Craig, “How Do You Feel? Interocep-tors: The Sense of the Physiological Conditionof the Body,” Nature Reviews 3 (2002): 655–666;Damasio, Looking for Spinoza.

motor structures that are about to com-mand the execution of a certain move-ment, to inform visual structures of thelikely result of that forthcoming move-ment. For example, when our eyes areabout to move toward an object at theperiphery of our vision, the visual re-gion of the brain is forewarned of theimpending movement and is ready tosmooth the transition to the new objectwithout creating a blur.

Second, it seemed obvious that simu-lating a body state without actually pro-ducing it reduces processing time andsaves energy.

Third, the neuroanatomical structuresneeded for the as-if body loop to workwere known to exist. The hypothesisrequired that the brain structures incharge of triggering a particular emo-tion be able to connect to the structuresin which the body state correspondingto the emotion would be mapped. Forexample, the amygdala (a triggering sitefor fear) and the ventromedial prefrontalcortex (a triggering site for compassion)would have to connect to somatosensingregions such as the insular cortex, sii,and si, where ongoing body states arecontinuously represented. We knew thatsuch connections existed, thereby ren-dering possible the implementation ofthe hypothetical mechanism.

In recent years, more support for thishypothesis has come from several quar-ters, for example, from a series of re-markable experiments by Giacomo Riz-zolatti and his colleagues. These experi-ments identi½ed a class of nerve cells,known as ‘mirror neurons,’ by means of implanted electrodes in monkeys. In these experiments, a monkey wouldwatch an investigator perform a varie-ty of actions.5 When a monkey saw the

investigator move his hand or mouth,neurons in the monkey’s brain regionsrelated to hand or mouth movementsbecame active, ‘as if’ the monkey wereperforming the action. But in reality, themonkey remained immobile.

Mirror neurons are, in effect, the ul-timate ‘as-if body’ device. The mirror-neuron system achieves conceptuallywhat we hypothesized as the ‘as-if bodyloop’ system: the simulation, in thebrain’s body maps, of a body state that is not actually taking place in the organ-ism. The fact that the body state the mir-ror neurons are simulating is not thesubject’s does not minimize the powerof this functional resemblance. On thecontrary, it stands to reason that if acomplex brain can simulate someoneelse’s body state, it can simulate one ofits own body states. Take, for example, a state that has already occurred in theorganism: it should be easier to simulatesince it has already been mapped by pre-cisely the same somatosensing struc-tures that are now responsible for simu-lating it. In fact, we suggest that the as-if system applied to others would nothave developed had there not been anas-if system applied to the brain’s ownorganism.

The nature of the brain structures in-volved in the process reinforces the sug-gestive functional resemblance betweenthe as-if body loop and mirror neurons.For the as-if body loop, we hypothesizedthat neurons in areas engaging emotion–the premotor/prefrontal cortex (in thecase of compassion), the anterior insularcortex (in the case of disgust), and theamygdala (in the case of fear)–wouldactivate regions that normally map thestate of the body and, in turn, move it


Minding the body

5 G. Rizzolatti, L. Fadiga, L. Fogassi, and V. Gallese, “Resonance Behaviors and Mirror

Neurons,” Archives Italiennes de Biologie 137(1999): 85–100; V. Gallese, “The Shared Mani-fold Hypothesis,” Journal of Consciousness Stud-ies 8 (2001): 33–50.

to action. In humans such regions in-clude the somatomotor complex in therolandic and parietal operculum as wellas the insular cortex. All of these regionshave a dual somatomotor role, the insu-lar cortex providing an especially goodexample of this functional duality. Thatis, these regions can hold a map of thebody state, a sensory role, and they canparticipate in an action as well. By andlarge, this is what Rizzolatti’s neuro-physiologic experiments with monkeysuncovered. This discovery is quite con-sonant as well with human studies usingmagnetoencephalography (the studies of Rita Haari) and functional neuroima-ging (again by the Rizzolatti group andby Tania Singer and her colleagues). Ourown studies based on neurologic lesionspoint in the same direction.6

Explanations of the existence of mir-ror neurons have emphasized, quite ap-propriately, the role that mirror neuronscan play in allowing us to understand theactions of others by placing us in a com-parable body state. As we witness an ac-tion in another, our body-sensing brainadopts the body state we would havewere we ourselves moving, and it doesso, in all probability, not by passive sen-sory patterns, but rather by a preactiva-tion of motor structures–ready for ac-tion yet not quite allowed to act–and insome cases by actual motor activation.

We must wonder, however, how such a complex physiologic system evolved.We doubt it arose de novo, simply be-cause of the manifest advantage of bet-ter knowing the body state of othersand, through it, the mind state of oth-ers. Instead, we suspect that the mirrorsystem developed from an earlier ‘as-if body loop’ system, which complexbrains used to simulate their own bodystates for a clear and immediate advan-tage: rapid and energy-saving activa-tion of the maps of certain body states,which were, in turn, associated with relevant past knowledge and cognitivestrategies. Eventually, the as-if systemwas applied to others and prevailed be-cause of the equally obvious social ad-vantages one could derive from know-ing the body states of others, which areconnected, of course, to their mentalstates.

In brief, we regard the remarkable evi-dence for mirror neurons as support forthe ‘as-if body loop’ mechanism of plac-ing the body in mind. In turn, we con-sider the ‘as-if body loop’ system with-in each organism as the precursor to themirror-neuron system.

The as-if body loop, the body loop, and mirror neurons all point to a fewremarkable features regarding the per-ception of the body during the experi-ence of an emotion: The emotion endsup felt in our flesh. The process unfoldsin time and is both sensory and motor.The sensing of body changes leads tomotor activations that, in turn, can besensed. All of these steps have the pow-er to evoke related knowledge held inmemory.

There is a peculiar relationship be-tween the object perceived, our body,and the brain. The body and brain in-habit the same organism, and the rela-tionship between the two can be entire-



6 R. Haari, N. Forss, S. Avikainen, E. Kirves-kari, S. Salenius, and G. Rizzolatti, “Activa-tion of Human Primary Motor Cortex DuringAction Observation: A Neuromagnetic Study,”Proceedings of the National Academy of Sciences95 (1998): 15061–15065; T. Singer et al., “Em-pathy for Pain Involves the Affective but notSensory Components of Pain,” Science 303(2004): 1157–1162; R. Adolphs, H. Damasio, D. Tranel, G. Cooper, and A. Damasio, “A Rolefor Somatosensory Cortices in the Visual Rec-ognition of Emotion as Revealed by Three-Di-mensional Lesion Mapping,” Journal of Neuro-science 20 (2000): 2683–2690.

ly circular. Feelings of emotions can helpillustrate the situation.

Feelings of emotions are perceptions.They are, in the general scheme ofthings, comparable to other perceptions.For example, actual visual perceptionscorrespond to external objects whosephysical characteristics impinge on ourretinas and modify transiently the sen-sory maps in the visual system. Feelingsof emotions also have an object at theorigin of the process, and the physicalcharacteristics of the object also prompta chain of signals that impinges on mapsinside the brain.

In other words, just as in the case ofvisual perception, a part of feelings ofemotion is due to the object, and a partis due to the internal construction thebrain makes of it. But something is quitedifferent in the case of feelings, and thedifference is not trivial. In feelings, theobject at the origin of the process is in-side the body rather than outside. Feel-ings of emotion are just as mental as anyother perception, but a sizable part ofthe objects being mapped are states ofthe living organism in which the feelingsarise.

As if this difference does not compli-cate things enough, there is anotherwrinkle in the process: feelings of emo-tion are linked to an object called thebody, but they are also linked to theemotionally competent object that ini-tiated the emotion-feeling cycle. A spec-tacular seascape is an object, but so is the body state that results from behold-ing that seascape, and it is the latter ob-ject at the origin of the emotional pro-cess that we perceive in the resultingfeeling state.

In feeling, the brain can act directly onthe very object that it is perceiving, be-cause the object at the origin is insidethe body. It can do so by modifying thestate of the body, or by altering the

transmission signals from it. Thus, theobject at the origin, on the one hand,and the brain map of that object, on theother, can exert mutual influences in asort of reverberative process that is notto be found in the perception of an ex-ternal object. We can look at a paintingwe admire as intensely as we wish, for as long as we wish, and react emotional-ly to it. But nothing will happen to thepainting itself. Our thoughts about itwill change, but the object remains in-tact.

By contrast, in the feeling of emo-tion, the object itself–the body–can be changed radically. In other words, the feeling of emotion is not merely apassive perception or a flash in time. For a period of seconds or even minutesafter a feeling begins, a dynamic engage-ment of the body, conducted almost cer-tainly in a reiterative fashion, leads to a dynamic variation of the perception.Part of the variation may even be due tothe homeostatic necessity of controllingthe motor upheaval caused by the emo-tive process.7 In brief, the body in themind undergoes continuous transitions.

The fact that the body of a given organ-ism can be fully represented in the brainof that organism opens important pos-sibilities. The ½rst relates to conscious-ness, speci½cally with the part of theprocess called the self. Elsewhere wehave argued that the construction ofthe self would simply not be possible if the brain did not have available a dy-namic representation of its body.8 Con-


Minding the body

7 D. Rudrauf and A. Damasio, “A ConjectureRegarding the Biological Mechanism of Subjec-tivity and Feeling,” Journal of ConsciousnessStudies 12 (8–10) (2005): 236–262.

8 Damasio, The Feeling of What Happens; J. Par-vizi and A. Damasio, “Consciousness and theBrainstem,” Cognition 79 (2001): 135–160.

sciousness is about the relation betweena given organism and the objects per-ceived in its mind. In the mental processdepicting the self, the integrated bodyrepresentation serves as a stand-in forthe organism. There is an invariant as-pect to the body representation–itscomponents and the schema accordingto which they are interconnected–and a variable aspect–the dynamic changesthe components constantly undergo.Eventually the body representation be-haves as an anchor for the constructionof the self–a mental stand-in for the in-dividual, for his or her personhood andidentity.

These body representations haveanother major implication: after allow-ing us to represent our own actions andemotional states, actual or simulated,they allow us to simulate the equivalentstates of others. And because we haveestablished a prior connection betweenour own body states and their signi½-cance, we can subsequently attribute thesame signi½cance to the states of othersthat we come to simulate. The body inmind helps us construct our selves andthen allows us to understand others,which is nothing short of astounding.



damasio minding the body

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