rao@enuxha.eas.asu.edu (Arun Rao) (03/03/89)
In article <32129@gt-cmmsr.GATECH.EDU>, kirlik@hms3 (Alex Kirlik) writes: > Some researchers explain the successes of neural-net models ^^^^^^^^^ > (in mimicking human behavior) in terms of their similarity > with the structure and mode of processing in the brain. Success is relative - no researcher, to my knowledge anyway, has ever succeeded in mimicking any brain function completely. At this stage in neural-network research, people are happy just to achieve something that conventional (read AI, pattern recognition) techniques cannot. Sometimes even this advantage is questionable if you look at some theories closely. > > Now, if one wants to use such an explanation, I contend that > the burden of proof is on that person to explain why their > model with a small number of neural units behaves in the same > way as the brain which uses a larger number of neurons to [ stuff deleted ] > as used by the brain). Rather, my question is: How can we use the > brain analogy to explain the successes of our models when we > cannot specify the referential relation that holds between our > theoretical constructs (units) and the world (the brain)? > Most current approaches attempt to use hints from neurobiology/ psychology in order to propose theories. The contention is that if a small number of neurons can perform a very elementary function, then perhaps a large number will be capable of more complex functions. There have been at least some approaches which *require* the existence of large numbers of units before emergent properties can be observed. Some graph theoretic approaches belong to this category. In summary, I don't think anyone contends that their model is in any respect a complete representation of even a part of the human brain even though some theories may assume a many-to-one correspondence. All are admittedly gross simplifications, but one has to start somewhere ! - Arun Rao > > Alex Kirlik > -- Arun Rao ARPANET: rao@enuxha.asu.edu BITNET: agaxr@asuacvax 950 S. Terrace Road, #B324, Tempe, AZ 85281 Phone: (602) 968-1852 (Home) (602) 965-3424 Ext. 3092 (Office)