8/13/2019 Damasio - Fundamental Feelings

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Antonio Damasio

T

he groundwork for the science of emo-tion was laid down most auspiciously

over a century ago, but neuroscience hasgiven the problem a resolute cold shoulderuntil recently. By the time that Charles Dar-win had remarked on the continuity of emo-tional phenomena from non-human speciesto humans; William James had proposed aninsightful mechanism for its production;Sigmund Freud had noted the central role ofemotions in psychopathological states; andCharles Sherrington had begun the physio-logical investigation of the neural circuitsinvolved in emotion, one might have expectedneuroscience to be poised for an all-out attackon the problem. It is not usually appreciated

that the probable cause of the neglect of thetopic was the improper distinction betweenthe concepts of emotion and feelings.

Some traits of feelings their subjectivenature, the fact that they are private, hiddenfrom view, and often difficult to analyse were projected onto emotions, so that theytoo were deemed subjective, pr ivate, hiddenand elusive. Not surprisingly, neuroscien-tists were disinclined to give their bestefforts to a problem that did not seem tobe amenable to proper hypothesizing andmeasurement. Somewhat alarmingly, thisconflation of the two concepts persists, as

does the idea that the neurobiology of feel-ings is out of reach. A clari fication is in order.An emotion, be it happiness or sadness,

embarrassment or pride, is a patternedcollection of chemical and neural responsesthat is produced by the brain when it detectsthe presence of an emotionally competent

stimulus an object or situation, for exam-ple. The processing of the stimulus may beconscious but it need not be, as the responsesare engendered automatically. Emotional

responses are a mode of reaction of brains thatare prepared by evolution to respond to cer-tain classes of objects and events with certainrepertoires of action. Eventually, the brainassociates other objects and events that occurin individual experience with those that areinnately set to cause emotions, so that anotherset of emotionally competent stimuli arises.

The main target of the emotionalresponses is the body the internal milieu,the viscera and the musculoskeletal system but there are also targets within the brainitself, for example, monoaminergic nuclei inthe brainstem tegmentum. The result of the

body-targeting responses is the creation ofan emotional state involving adjustmentsin homeostatic balance as well as theenactment of specific behaviours, such asfreezing or fight-or-flight, and the produc-tion of particular facial expressions. Theresult of the brain-targeting responses is analteration in the mode of brain operationduring the emotional body adjustments, theconsequence of which is, for example, achange in the attention accorded to stimuli.

Emotions allow organisms to copesuccessfully with objects and situations thatare potentially dangerous or advantageous.

They are just the most visible part of a hugeedifice of undeliberated biological regula-tion that includes the homeostatic reactionsthat maintain metabolism; pain signalling;and drives such as hunger and thirst. Mostemotional responses are directly observableeither with the naked eye or with scientificprobes such as psychophysiological andneurophysiological measurements andendocrine assays. Thus, emotions are notsubjective, private, elusive or undefinable.Their neurobiology can be investigatedobjectively, not just in humans but in labora-tory species, from DrosophilaandAplysiato

rodents and non-human primates.A working definition of feelings is adifferent matter. Feelings are the mentalrepresentation of the physiological changesthat characterize emotions. Unlike emo-tions, which are scienti fically public, feelingsare indeed private, although no more subjec-tive than any other aspect of the mind, forexample my planning of this sentence, or themental solving of a mathematical problem.Feelings are as amenable to scienti fic analysisas any other cognitive phenomenon, pro-vided that appropriate methods are used.Moreover, because feelings are the directconsequences of emotions, the elucidationof emotional neurobiology opens the way to

elucidating the neurobiology of feelings.If emotions provide an immediate

response to certain challenges and opportu-nities faced by an organism, the feeling ofthose emotions provides it with a mentalalert. Feelings amplify the impact of a givensituation, enhance learning, and increase theprobability that comparable situations canbe anticipated.

The neural systems that are involved inthe production of emotions are being identi -fied through studies of humans and other

animals. Various structures, such as theamygdala and the ventromedial prefrontalcortices, trigger emotions by functioning asinterfaces between the processing of emo-tionally competent stimuli and the executionof emotions. But the real executors of emo-tions are structures in the hypothalamus, inthe basal forebrain (for example, the nucleusaccumbens) and in the brainstem (forexample, the nuclei in the periaqueductalgrey). These are the structures that directlysignal, chemically and neurally, to the bodyand brain targets at which alterationsconsti tute an emotional state.

No less importantly, recent functionalimaging studies reveal that body-sensingareas, such as the cortices in the insula, thesecond somatosensory region (S2) and thecingulate region of the brain, show a statisti -cally significant pattern of activation ordeactivation when normal individuals exp-erience the emotions of sadness, happiness,fear and anger. Moreover, these patterns varybetween different emotions. Those body-related patterns are tangible neural correlatesof feelings, meaning that we know where tolook further to unravel the remaining neuro-physiological mysteries behind one of the

most criti cal aspects of human experience.

Antoni o Damasio i s in the Department of Neurology,

Uni versity of I owa College of Medicine, 200 Hawkins

Dr ive, Iowa City, Iowa 52242, USA.

FURTHER READING

Damasio, A. R. The Feeling of What Happens: Body and

Emotion in the Making of Consciousness(Harcourt

Brace, New York, 1999).

Davidson, R. J. & Irw in, W. Trends Cogn. Neurosci .3,

1122 (1999).

Panksepp, J. Affective Neuroscience: The Foundations

of Human and Animal Emotions(Oxford Univ. Press,

New York, 1998).

Vuillemier, P., Driver, J., Armony, J. & Dolan, R. J.

Neuron30 , 829841 (2000).

Fundamental feelings

concepts

NATURE| VOL 413| 25 OCTOBER 2001| www.nature.com 78 1

Emotion

Emotion and feelings are closely

related but separable phenomena;

their elucidation, at long last, is now

proceeding in earnest.

VICKYASKEW

2001 Macmillan Magazines Ltd