Vladimir Nesov wrote:
On Fri, Nov 21, 2008 at 8:09 PM, Richard Loosemore <[EMAIL PROTECTED]> wrote:
Ben Goertzel wrote:
Richard,
My point was that there are essentially no neuroscientists out there
who believe that concepts are represented by single neurons. So you
are in vehement agreement with the neuroscience community on this
point.
The idea that concepts may be represented by cell assemblies, or
attractors within cell assemblies, are more prevalent. I assume
you're familiar with the thinking/writing of for instance Walter
Freeman and Susan Greenfield on these issues. You may consider them
wrong, but they are not wrong due to obvious errors or due to
obliviousness to cog sci data.
So let me see if I've got this straight: you are saying that there are
essentially no neuroscientists who talk about spiking patterns in single
neurons encoding relationships between concepts?
Not low-level features, as we discussed before, but medium- to high-level
concepts?
You are saying that when they talk about the spike trains encoding bayesian
contingencies, they NEVER mean, or imply, contingencies between concepts?
What's a concept in this context, Richard? For example, place cells
activate on place fields, pretty palpable correlates, one could say
they represent concepts (and it's not a perceptual correlate). There
are relations between these concepts, prediction of their activity,
encoding of their sequences that plays role in episodic memory, and so
on. At the same time, the process by which they are computed is
largely unknown, individual cells perform some kind of transformation
on other cells, but how much of the concept is encoded in cells
themselves rather than in cells they receive input from is also
unknown. Since they jump on all kinds of contextual cues, it's likely
that their activity to some extent depends on activity in most of the
brain, but it doesn't invalidate analysis considering individual cells
or small areas of cortex, just as gravitation pull from the Mars
doesn't invalidate approximate calculations made on Earth according to
Newton's laws. I don't quite see what you are criticizing, apart from
specific examples of apparent confusion.
No, object-concepts and the like. Not place, motion or action 'concepts'.
For example, Quiroga et al showed their subjects pictures of famous
places and people, then made assertions about how those things were
represented.
Richard Loosemore
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agi
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