22 October 2009

Speaking of mental trade-offs...

In my post about trade-offs in the brain I meant to mention a recent EconTalk podcast with cognitive psychologist Daniel Willingham on neuroscience and education. He raised an important point: there is often a behavioral trade-off between reasoning and memory, and the two modes of thinking are closely intertwined. The overlap and contrast between them is not well understood, nor are their neural correlates. What we call being "creative" is sometimes using a memory of a previously solved problem and applying it to a new situation, but sometimes it's (perhaps subconsciously) refusing to use a memorized solution and instead inventing a new one. I just wanted to clear up that I think there are cognitive trade-offs, but I am less confident in assertions of neural trade-offs.*

(* To clarify: By 'neural trade-offs' I mean physical limitations. I hear many people say something like "you only have so much brain tissue, so if you're good at some cognitive function, you're probably bad at another." I think the science behind these assertions ranges from entirely discredited to just unsupported one way or the other at present. On the other hand, cognitive trade-offs are largely temporal. It is fairly well established that even the best "multi-taskers" can only pay attention to a very limited number of things at one time. (Perhaps as few as a single thing, depending on the modeling assumptions you make about context switching.) A lot of this is still very open-ended, and a lot depends on the assumptions and language you use to describe your model, but I'm confident in saying that there is a lot more reason to believe in cognitive rather than neurophysical trade-offs.

As a further aside, part of the reason that problem is still left unsolved is because pinning down what attention is, and how to model it, and how to even describe it, is a tricky business. We all pretty much agree whether you correctly remembered a phone number or can see how many kittens there are in a picture, but what does it mean to say you are paying attention to something?

That difficulty is further compounded because a lot of the scientific efforts on this front come perilously close to being ... gasp! ... philosophical in nature, so many scientists shy away from in-depth theories of attention as being too soft to deserve rigorous study. Attention butts right up against consciousness, and consciousness is dangerous territory for a scientist to get involved in if they want to be considered serious. There's still a lot of work on attention being done (including by yours truly, and rest assured, I will get to the bottom of this matter!) but it's a tentative business.)

Anyway, it's a good podcast and covers a range of topics. This is also a solidly non-ideological episode for any non-libertarians who shy away from EconTalk. I especially liked the discussion of math education. Willingham mentioned that a remarkably high percentage of sixth graders don't understand what an equals sign means and tend to think it means "put the answer here" rather than "these two quantities (however they may be expressed) are equivalent to one another."

I also agree that one of the fundamental problems in education, and something we sweep entirely under the rug, is that we can't agree on what an education is actually for. Is it for getting a job? For personal fulfillment? To strengthen the polity? To make the world a more just place? Is knowledge its own goal?

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