evolutionary and computational theories of mind

yan king yin (dont spam) y.k.y at lycos.com
Sun Jan 20 23:01:34 EST 2002

"mat" <mats_trash at hotmail.com>
> Of course evolution can only work in a piecemeal fashion.  Genes are
> what evolution works on by selecting for the rare random mutations
> that benefit an organism in its particular environment.  It is
> unlikely if not impossible that a single mutation suddenly gave rise
> to our abilities to reason, make informed decisions, participate in
> more complex societies and generate language etc..  But thats what you
> would require.  Evolution needs things to occur bit by bit but its
> very difficult to see with some of our cognitive abilities how they
> can be divided into 'chunks' that could seperately evolved.  That's
> why evolutionary psychologists have to break things down into modules.
>  Of course, the genes themselves don't have to code for a specificed
> cognitive module but can provide the conditions upon which an
> animal/person can learn or adapt in its social environment.  Further
> to this you can imagine a series of 'good' mutations that gave the
> brain greater size and scope for plasticity.

I didnt mean to say that evolution does not work in a piecemeal fashion,
in the sense that it makes baby steps by random mutations. I wanted to
say that the brain does not have separate modules for different cognitive
functions such as language. Sorry about the confusion.

My idea is that genes only determine the statistical patterns of neural
connectivity, and individual synaptic weights are "uninitialized". It is
left for the job of learning and experience to form the cognitive abilities.
Another extreme would be that there exists specific circuits for each
cognitive function but I think that is unlikely. Its hard to imagine how
specific connections can be specified by genes. But there might be
patterns of connectivity that predisposes an area for a certain function
such as language.

> One thing I would say about the computtational approach is that it
> gives the idea that were we to put a brain a totally new environment
> with new stimuli it would deal with them in a computational manner
> etc.. however, all the brain has evolved to do is match appropriate
> output with incoming stimuli and memory.  The domain the brain has had
> to work in has shaped its evolution, the brain did not evolve as a set
> of circuits which then interpreted the environment.

I think Im more inclined towards the computational approach. This
question is more meaningful when it gets down to the details of what is
actually encoded by the genes.

If there is a language circuit, then why dont we all speak the same language?
So I think there is no language circuit.

Examples of other cognitive functions include: face recognition, theory
of mind, jealousy, and reasoning abilities. I tend to think that all of these
are emergent from a few basic computational mechanisms such as
classical/operant conditioning, pattern recognition and associative learning.

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