Monday, June 27, 2005

The brain is a "dynamic continuum," study says


Here is something to add to the conversation about how the brain works and the way computers work. This news post on Eurekalert by Cornell is a very concrete look at this subject.

Cornell psycholinguist Michael Spivey says the theory that the mind works like a computer, in a series of distinct stages, was an important steppingstone in cognitive science, but it has outlived its usefulness. Instead, the mind should be thought of more as working the way biological organisms do: as a dynamic continuum, cascading through shades of grey. He has been focused on analyzing language comprehension processes.

In a new study published online this week in Proceedings of the National Academy of Sciences, Spivey tracked the mouse movements of undergraduate students while working at a computer. The findings provide compelling evidence that language comprehension is a continuous process.

Spivey says in the new model, "perception and cognition are mathematically described as a continuous trajectory through a high-dimensional mental space; the neural activation patterns flow back and forth to produce nonlinear, self-organized, emergent properties - like a biological organism.

"In thinking of cognition as working as a biological organism does, on the other hand, you do not have to be in one state or another like a computer, but can have values in between - you can be partially in one state and another, and then eventually gravitate to a unique interpretation, as in finally recognizing a spoken word.

"Whereas the older models of language processing theorized that neural systems process words in a series of discrete stages, the alternative model suggests that sensory input is processed continuously," Spivey says.

This bit of news is really over my head, but I do know that Spivey has published in the premier science publication, the PNAS, so scientists interested in computers and artificial intelligence (AI) will be checking this out!

1 comment:

David Collin said...

Nice pictures!

I think it's becoming evident that, one way or another, "thought" processes are non-linear. I read an article the other day about "persistent" learning by neurons. One of the statements was that neuro-chemical processes at the synapse are probabilistic, not certain.

If this is the case I'm wondering why we're in such a rush to invent AI. My guess is that thought and consciousness are going to end up as variable and uncertain in machines as human minds are. We'll end up giving up linear certainty and axiomatic logic to get "intelligences" that are subject to bias and variables of input and experience.