What have neural networks achieved?

[Adrian Robert]

After Dr. Arbib's request everyone seems to have been coming up with  
commercial applications (using NNs as statistical analyzers) but as far as his  
first question -- about generation of insight into real brain function --  
zero.

Lest this be taken as a sinister sign in yet another area of neural network  
research, I hurry to mention the one major example that I'm familiar with --  
that of understanding the influence of environmental input on cortical neural  
representations.  The work I'm talking about is of course that done, starting  
with von der Malsburg and others in the 70's, given a fresh impulse by Linsker  
in the 80's, and most thoroughly connected to the biology by Miller in the  
90's, on the development of orientation selectivity (and also maps of  
orientation selectivity and ocular dominance columns) in primary visual  
cortex.  While anyone in the field will tell you that the final word has yet  
to be said, this work genuinely provides insight -- it shows how the important  
elements of a class of biological neural systems can be translated into  
mathematical terms and how observed results emerge naturally from this  
translation.  You leave an encounter with it feeling you have really  
understood something about the way things work -- and, although these methods  
have only been applied to the first visual area in the cortex (for the most  
part), they are general enough that they provide more than an inkling about  
what must be happening further in.  (Long way to go though!)

There are other examples...


Adrian