DRogers%MIT-OZ@MIT-MC.ARPA (03/06/84)
From: David Rogers <DRogers%MIT-OZ@MIT-MC.ARPA>
For a very good (if 3 years old) discussion on parallism
in the brain, refer to Hinton and Anderson's book "Parallel
Models of Associative Memory, pages 32-44 [Hin 81]. The
applicable section is entitled "Parallelism and Distribution
in the Mammalian Nervous System". Structurally, paralleism is
inherent throughout the nervous system, making simple
sequential models of human low-level cognition highly
suspect.
Though it was not openly stated in the discussion on this list,
there seems to be two issues of parallelism involved here:
low-level parallelism, and parallelism at some higher
"intellectual" level. The latter subject is rightly the domain
for experimentalists, and should not be approached with
simple AI techniques as introspection ("Well, I *feel*
sequential when I think...").
One known experimental fact does suggest a high degree of
parallelism, even in higher cognitive functions. Since
the firing rate of a neuron is on the order of
2-3 milliseconds, and some highly complex tasks (such as
face recognition) are performed in about 300 ms, it seems
clear that the brain uses massive parallelism, not just
in the visual system but throughout [Fel 79].
I would suggest that future discussions offer the reader
a few more experimental details, lest the experimental
psychologists in our midst feel unappreciated.
---------
[Hin 81]
"Parallel Models of Associative Memory, G. Hinton,
J. Anderson, eds, Laurence Earlbaum Assoc., 1981, pages 32-44.
[Fel 79]
"A Distributed Information Processing Model of Visual
Memory", J.A. Feldman, University of Rochester Computer
Science Department, TR52, December 1979.