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
on the shelf. _An Anthropologist on Mars_ (1995) is by Oliver Sacks, the
neurologist author of _Awakenings_ and _The Man Who Mistook His Wife for a
Hat_, and as with these other books, engagingly presents the case histories
of a few of Sacks'es patients who were or are afflicted with various types
of brain disease or injury. Thus far I have read only two of the seven
cases presented, but judging from these the book should be of interest to
many CSG-L subscribers.

_The Case of the ColorBlind Painter, the first chapter, recounts the case of
"Mr. I," an artist who awoke the morning following an auto accident to find
himself able neither to read nor to perceive color. Although his reading
ability 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
a distasteful, "dirty" look, the whites glaring, yet discolored and
off-white, the blacks cavernous--everything wrong, unnatural, stained, and
impure."

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

"Mr. I. was seeing with his cones, seeing with the wavelength-sensitive
cells of V1 [visual area 1], but unable to use the higher-order,
color-generating mechanism of V4. For us, the output of V1 is unimaginable,
because it is never experienced as such and is immediately shunted on to a
higher level, where it is further processed to yield the preception of
color. Thus the raw output of V1 never appears in awareness for us. But
for Mr. I. it did--his brain damage had made him privy to, indeed trapped
him within, a strange inbetween state--the uncanny world of V1--a world of
anomalous and, so to speak, prechromatic sensation, which could not be
categorized as either colored _or_ colorless."

This account appears entirely compatible with the view that perception at
each stage is represented by a scalar neural current, and that various
stages in the visual processing system each extract or create their own
representations by operating on the scalar values of prior-stage outputs.
It also supports the view that the imagination mode depends on the
functioning of the same neural structures that perform these transformations
on sense-data.

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

Regards,

Bruce

[From Rick Marken (950227.0845)]

Bruce Abbott (950226.1745 EST) --

_An Anthropologist on Mars_ (1995) is by Oliver Sacks

And it was not just Mr. I's PERCEPTION of color that was missing; he could
no longer IMAGINE in color, could no longer DREAM in color.

This account appears entirely compatible with the view that perception at
each stage is represented by a scalar neural current, and that various
stages in the visual processing system each extract or create their own
representations by operating on the scalar values of prior-stage outputs.
It also supports the view that the imagination mode depends on the
functioning of the same neural structures that perform these transformations
on sense-data.

Yes. Excellent observation, Bruce!

Fascinating, huh?

Yes, Thanks for the "heads up" on the book and the nice descriptions of some
of the cases.

Best

Rick

[Martin Taylor 950227 15:30]

Clark Mcphail (undated)

Demasio concludes by
saying that what is needed is a hiearchical formulation which (to me and
not surprisingly to Mary) looks very much like William T. Powers'
perception control theory. I had the same reaction to Francis Crick's
book, _The Astonishing Hypothesis: the Scientific Search for the Soul_. His
hypothesis? All we can know about the world is what we experience through
our sensory receptors and they can only tell us about intensities.
Everything else is in the neurons! He concludes that those intensity
perceptions must be compiled and compounded through some hierarchical
arrangement of perceptions. Francis Crick? Meet William T. Powers. He's
already arrived at the destination you propose for current and future
neuroscientific research.

Actually, the notion of the hierarchy of perception is probably one of the
earliest theoretical structures of modern psychology. It dates back at
least to Donders, around 1860, and has never long left the mainstream of
psychological thought. What is different about Powers' work is the
control aspect--behaviour being the control of those hierarchically
organized kinds of perception, rather than actions being the consequences
of the perceptions at different levels. From what you say of Crick, he
isn't rediscovering Powers; he's rediscovering Donders, a century and
more late.

When I was aged about 8, my parents bought me Collins (I think) Children's
Encyclopaedia, in which there was a fascinating article about the hierarchy
of perception. I didn't know it was "psychology" until some 20 years later,
but I did believe that I was being told how people worked, in some measure.

The hierarchy isn't new, but as far as I know, Powers' synthesis is, as it
goes some way beyond William James (multiple means to any given end).

Martin