From: Gary Miller (garymiller@starband.net)
Date: Fri Feb 14 2003 - 10:53:05 MST
>> Indeed you could see a somewhat distorted but easily identifiable
grid in their primary visual cortex.
If this were true then coroners could perform the same procedure on
murder victims and get an
Image of the murderer.
I've seen this plots similar to this in B SciFi movies, but never
considered that this would actually be possible.
-----Original Message-----
From: owner-extropians@extropy.org [mailto:owner-extropians@extropy.org]
On Behalf Of Rafal Smigrodzki
Sent: Thursday, February 13, 2003 6:11 PM
To: extropians@extropy.org
Subject: RE: Where the I is
Brent Allsop wrote:
> Lee said:
>>>> Monkeys eyes were held fixed while they
> steadily looked at a certain geometric
> figure (a grid or a triangle, I forget).
> Then they were instantly killed, and it
> was found that this same grid was
> present, and spatially too, in their
> visual cortex (at the back of their heads).
> So it seems that we do have a picture in
> our heads for visual information.<<<
>
> This is new to me and frankly hard to believe. The representations
> survive past death?? Do you have some references or something?
>
### This was a classical experiment with radioactively labeled
deoxyglucose (if I remember correctly) being taken up while the monkey
looked at a spiderweb grid (actually a target used in ophthalmology to
analyze visual fields). The nerve cells activated by the target burned
more energy, and took up the label more than inactive cells. Indeed you
could see a somewhat distorted but easily identifiable grid in their
primary visual cortex.
However, we have to remember that only a very small number of neurons,
if any, in the primary visual cortex, is correlated with conscious
experience.
Rafal
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