What the Neocortex Does

Harry Erwin herwin at gmu.edu
Tue Aug 1 17:34:06 EST 2000

Bill Skaggs <skaggs at bns.pitt.edu> wrote:

> herwin at gmu.edu (Harry Erwin) writes:
> > I'm beginning to suspect a primary function of the neocortex is the
> > maintenance of a non-symbolic, dynamic model of the environment. The
> > evidence seems fairly strong that bats live mostly in such a model
> > (Griffin, 1958), and the difficulty we have training bats to use
> > symbolic representations (yes/no tokens) in communicating with us,
> > suggests that their internal model is non-symbolic, possibly like the
> > analog models used in some contexts like wind tunnels and floatation
> > tanks. 
> Hi Harry!
> I gather from this that you're having trouble training a bat to do a
> task.
> Anyway, you may be right but I don't think the argument is convincing.
> Whatever sort of environment-model bats have, they certainly are
> capable of using it to make at least some binary distinctions (e.g.,
> moth/leaf).
>       -- Bill

Maybe I need to add that bats _do_ compute a prediction of the future
position of moving targets. They're able to handle linear, circular, and
ballistic motion. The experiments involving linear motion were
particularly interesting because the targets were made to disappear for
most of the path, and the bats still handled the problem.

That only shows that bats compute. It does not show that they use a
non-symbolic means of computation. On the other hand, it has some
relevance to Church's thesis, since I haven't been able to identify the
mechanism of a Turing machine (or any of the alternatives) in the
anatomy 8).


Harry Erwin, PhD, <mailto:herwin at gmu.edu>,Computational Neuroscientist 
(modeling bat behavior), Senior SW Analyst and Security Engineer, and 
Adjunct Professor of Computer Science, GMU. Looking--CV available at: 

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