Mike Palij wrote: > >> You may be right that parallel distributed connectionist models (a less >> tendentious name for "neural networks") >> > > "Tendentious"? Not to argue the point but considering that > one can trace these models back to McCulloch & Pitts (1943) > and other models of the nervous system (and even earlier > connectionist conceptions), couldn't one claim that "neural > network" has priority in describing these types of models? > > Origin is not essence, as they say. Yes, McCulloch & Pitts were one (two, actually) of the first to use these kinds of models (you'll find something similar slightly earlier in Rashevsky), but there was nothing particularly "nervous" about them (apart from McCulloch's use of the term). There are at least as many disanalogies between them and neural structure as there are analogies, and there are all kinds of ways to interpret their activity that has nothing whatever to do with neural modeling (See Green, 1998, 2001). >> were mathematically too difficult for most psychologists, >> but that only goes to show just how mathematically inept >> most psychologists are. There is nothing in connectionist >> models that can't be understood after a single year of >> basic calculus. >> > > Actually, wouldn't it be true that one could understand connectionist > models after a review of matrix algebra? Correct me if I'm wrong > but isn't the calculus used mainly for find a minimum or maximum > solution for the weight matrix? > One needs a little matrix arithmetic (but not really algebra) to do these (and if one is programming the matrix arithmetic is usually handled explicitly, scalar by scalar, in loops, not in matrix notation. Doing backprop, however, requires one to take derivatives of the learning rule. (Of course, there are lots of other ways to go besides backprop but (1) it is extermely popular and (2) most other learning procedures require some bsic calculus as well.
> It might be just me but it seems that J.J. Gibson might be becoming > increasingly relevant to cognitive psychology. Aren't Gibsonians fond > of saying "it's not what's inside your head that's important, it's what > your head is inside of that is". Or something like that. > > I've always thought that J. J. Gibson was important (but, then again, my own supervisor was one of his students, so I got a heavy dose of ecological psych when I was a grad student). IMHO, Gibsonians (like Brooks) overstate the case -- the trick is not to abolish cognition, but to conceive of it in an ongoing interaction with the environment -- but they are still on to something important. Now if we could only cash out the fascinating insight of "affordances." :-) Refs: Green, C. D. (1998). Are connectionist models theories of cognition? <http://psycprints.ecs.soton.ac.uk/archive/00000553/> /Psycoloquy <http://psycprints.ecs.soton.ac.uk/>, 9/ (4). Green, C. D. (2001). Scientific models, connectionist networks, and cognitive science <http://www.yorku.ca/christo/papers/models-TP2.htm>. /Theory and Psychology, 11/, 97-117. Regards, Chris -- Christopher D. Green Department of Psychology York University Toronto, ON M3J 1P3 Canada 416-736-2100 ex. 66164 [EMAIL PROTECTED] http://www.yorku.ca/christo/ ========================== --- To make changes to your subscription contact: Bill Southerly ([EMAIL PROTECTED])
