Descartes' Error, An Anthropologist on Mars

Unedited posts from archives of CSG-L (see INTROCSG.NET):

Date: Mon Feb 20, 1995 10:50 am PST

Subject: Re: Damasio and PCT (From Mary)

[from Mary Powers 9502.20]

Bruce B: (asking if anyone has read Damasio's Descartes' Error)

I have -and am about to again. From what I remember from my first pass, I don't thinkit necessarily gives you ammunition for the point you are making, which Iunderstand to be that PCT is logical and cold and unemotional and is thereforeincapable of addressing the humanities and the arts.

I think a lot of people who live along an aesthetic dimension are veryresistant to the idea of having their experiences explained -that they will lose their magic if we know too much about them. So I ask you -does PCT fail to be "the whole story" because to some extent you really wouldrather not know PCT's version of the story?

But PCT is not about what people experience and feel. It's about the kindof organization needed in order to have experiences and feelings. Of coursethere is much more to being a person than understanding the organization ormechanism involved. As Bill said in BCP, the point is to explain as much as wecan -and the rest will be the interesting part. But there is no point drawing aline in advance between what PCT can explain and what it can't.

The role of emotions in living systems is certainly something PCT canaddress (there was a chapter on it in BCP that was cut out by the editor forsome reason -it is reprinted in Living Control Systems II). Disturbances and errors driveoutputs that affect the body -glands as well as muscles -and those effects are perceived -that is how we know something is not right and how we judge that what we aredoing is effective. More control loops.

What I found interesting in Damasio was the problem of Phineas Gage andothers with damage to very high levels. Of course these were accidents, no twoalike, with different degrees of damage to various sites. But what they seemedto have in common (to me) were pretty intact control systems up to andincluding the principle level -no problem understanding and discussing ethical principles, for instance. Whatseemed to be missing was the ability to designate a consistent set of referencevalues for the principle level -in other words, the system concept level was damaged or its connections tolower levels lost. Which would mean that any random setting of the principlelevel was as good as any other. And emotionally meant that there was noparticular criterion for feeling good or bad about anything.

I read the whole book feeling that it could be recast in PCT terms withoutdifficulty, and that doing so would make consistent sense of it. And at theend, in the postscriptum, I came across this paragraph:

Some have asked why neuroscience has not yet achieved results asspectacular as those seen in molecular biology over the past four decades. Somehave even asked what is the neuroscientific equivalent of the discovery of DNAstructure, and whether or not a corresponding neuroscientific fact has beenestablished. There is no such single correspondence, although some facts, atseveral levels of the nervous system, might be construed as comparable inpractical value to knowing the structure of DNA -for instance, understanding what an action potential is all about. But theequivalent, at the level of mind-producing brain, has to be a _large-scaleoutline of circuit and system designs_, involving descriptions _at bothmicrostructural and macrostructural levels_ [emphasis in text].

Dr. Damasio, meet Bill Powers.

Date: Sun Feb 26, 1995 3:20 pm PST

Subject: An Anthropologist on Mars

(From Bruce Abbott [950226.1745 EST])

Yesterday I went to the bookstore looking for a copy of _Descartes' Error_and, although that title was not in stock, I did find something interesting onthe shelf. _An Anthropologist on Mars_ (1995) is by Oliver Sacks, theneurologist author of _Awakenings_ and _The Man Who Mistook His Wife for aHat_, and as with these other books, engagingly presents the case histories ofa few of Sacks'es patients who were or are afflicted with various types ofbrain disease or injury. Thus far I have read only two of the seven casespresented, but judging from these the book should be of interest to many CSG-Lsubscribers.

_The Case of the ColorBlind Painter, the first chapter, recounts the caseof "Mr. I," an artist who awoke the morning following an auto accident to findhimself able neither to read nor to perceive color. Although his readingability returned, his color vision did not. Sacks describes the change:

"It was not just that colors were missing, but that what he did see had adistasteful, "dirty" look, the whites glaring, yet discolored and off-white,the blacks cavernous--everythingwrong, unnatural, stained, and impure."

And it was not just Mr. I's PERCEPTION of color that was missing; he couldno longer IMAGINE in color, could no longer DREAM in color. Yet, as Sackscarefully describes, the colors were not simply lacking, as in a black-and-whitephoto; the shades were distorted, so that Mr. I could not bear to look at hiscolor TV, preferring instead to use an old black and white set. In fact, thecolor receptors in his eyes were still functioning normally; the problem wascortical:

"Mr. I. was seeing with his cones, seeing with the wavelength-sensitivecells of V1 [visual area 1], but unable to use the higher-order,color-generatingmechanism of V4. For us, the output of V1 is unimaginable, because it is neverexperienced as such and is immediately shunted on to a higher level, where itis further processed to yield the perception of color. Thus the raw output ofV1 never appears in awareness for us. But for Mr. I. it did--hisbrain damage had made him privy to, indeed trapped him within, a strangeinbetween state--theuncanny world of V1--aworld of anomalous and, so to speak, prechromatic sensation, which could not becategorized as either colored _or_ colorless."

This account appears entirely compatible with the view that perception ateach stage is represented by a scalar neural current, and that various stagesin the visual processing system each extract or create their ownrepresentations by operating on the scalar values of prior-stageoutputs. It also supports the view that the imagination mode depends on thefunctioning of the same neural structures that perform these transformations onsense-data.

Fascinating, huh? Other stories (there are seven case histories presented)will be of interest to PCTers as well, such as _the Last Hippie_, whoseforebrain was disrupted by a tumor and refused to believe that he was totallyblind ("Wouldn't I be the first to know?"), although he was (his optic nerveswere destroyed), and _A Surgeon's Life_, which describes a Surgeon withTourette's syndrome, which produces among other symptoms controlled,coordinated movements which nevertheless are involuntary (an uncontrolledraising of references to lower systems at the program level or below?).

Regards, Bruce

Date: Mon Feb 27, 1995 9:41 am PST

Subject: Re: An Anthropologist on Mars

From Clark McPhail

>(Bruce Abbott [950226.1745 EST])

> Yesterday I went to the bookstore looking for a copy of _Descartes'Error_ and, although that title was not in stock, I did find somethinginteresting on the shelf. _An Anthropologist on Mars_ (1995) is by OliverSacks, the neurologist author of . . .

Thanks for calling Sack's new book to the attention of CSG-L.I do not yet have the book and have not read his account of the colorblindpainter or the other two cases you mention. I have read one of the chapters inthis book which is Sack's account of Virgil ("To see and not see") whichappeared in The New Yorker (May 10, 1993). I think this too will be of interestto CSG-L.This illustrates the interplay of multiple perceptual dimensions in the neuralnet as well as dramatically underscoring the point that intensity perceptionsmust be compiled in the central nervous system before they are meaningful tothe individual. I have been assigning this article to my students everysemester since I read it in 1993. Virgil began losing his eyesight through thedevelopment of cataracts at the age of 4 or 5 years; he was functionally blinduntil about the age of 50. For most of his adult life he worked as aprofessional masseuse at the local YMCA. Around the age of 50 his cataractswere surgically removed. His retinas could register intensities and variationsin sensations of light but the configurations were (with one interestingexception) all a blur. While visiting a zoo where his companions called to hisattention a large sculpture of a gorilla, Virgil could not "see" what it wasuntil he ran his hands over the blurred configuration and, drawing upon hisextensive tactile memory immediately said "Oh, its a great ape." The tragedy ofVirgil's story is that while he gradually gained some capacity to organizevisual sensations, he was constantly confused and very distressed. While heloved baseball, was a knowledgeable student of the game and had listened toradio broadcasts of games for years, he could not make sense of the confusingconfigurations flickering on the screen during telecasts of games played by hisfavorite team. He did learn to read simple phrases and those with enormousdifficulty. Tragically, Virgil succumbed to some vision-unrelateddisease and died within five years of regaining sight. Throughout most of thoseyears he was sighted but unseeing. I hope others on CSG-Lwill find Virgil's case as instructive as I did. I look forward to obtainingSack's book and reading the other cases he reports there.

Bruce (and others): Keep look for a copy of Demasio's book. It will beworth the search. I agree with Mary's assessment. Demasio concludes by sayingthat what is needed is a hierarchical formulation which (to me and notsurprisingly to Mary) looks very much like William T. Powers' perceptioncontrol theory. I had the same reaction to Francis Crick's book, _TheAstonishing Hypothesis: the Scientific Search for the Soul_. His hypothesis?All we can know about the world is what we experience through our sensoryreceptors and they can only tell us about intensities. Everything else is inthe neurons! He concludes that those intensity perceptions must be compiled andcompounded through some hierarchical arrangement of perceptions. Francis Crick?Meet William T. Powers. He's already arrived at the destination you propose forcurrent and future neuroscientific research.

Clark McPhail

Professor of Sociology