From: Rafal Smigrodzki (rafal@smigrodzki.org)
Date: Thu Feb 13 2003 - 16:11:16 MST
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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