One good way to think of the complexity of a single neuron is to think of it as taking about 1 MIPS to do its work at that level of organization. (It has to take an average 10k inputs and process them at roughly 100 Hz.)
This is essentially the entire processing power of the DEC KA10, i.e. the computer that all the classic AI programs (up to, say, SHRDLU) ran on. One real-time neuron equivalent. (back in 1970 it was a 6-figure machine -- nowadays, same power in a 50-cent PIC microcontroller). A neuron does NOT simply perform a dot product and feed it in to a sigmoid. One good way to think of what it can do is to imagine a 100x100 raster lasting 10 ms. It can act as an associative memory for a fairly large number of such clips, firing in an arbitrary stored pattern when it sees one of them (or anything "close enough"). Compared to that, the ability to modify its behavior based on a handful of global scalar variables (the concentrations of neurotransmitters etc) is trivial. Not simple -- how many ways could you program a KA10? But limited nonetheless. It still takes 30 billion of them to make a brain. Josh ------------------------------------------- agi Archives: http://www.listbox.com/member/archive/303/=now RSS Feed: http://www.listbox.com/member/archive/rss/303/ Modify Your Subscription: http://www.listbox.com/member/?member_id=8660244&id_secret=103754539-40ed26 Powered by Listbox: http://www.listbox.com
