Thursday, July 16, 2009

Neuroscience: The default brain network - humming along while we're idle

Here's an interesting summary on the default network in the brain, the one that's active when we aren't thinking about anything. (Tina Hesman Saey, "You are who you are by default" ScienceNews, July 18, 2009) Difficulty maintaining the network intact may be a factor in Alzheimer syndrome and schizophrenia.


Evolutionary psychology: David Brooks on the growing pushback

Everybody seems to be taking a whack at evolutionary psychology these days, and David Brooks gets in his shot in "Human Nature Today" (New York Times, June 26, 2009).

Evolutionary psychology has had a good run. But now there is growing pushback. Sharon Begley has a rollicking, if slightly overdrawn, takedown in the current Newsweek. And “Spent” is a sign that the theory is being used to try to explain more than it can bear.

The first problem is that far from being preprogrammed with a series of hardwired mental modules, as the E.P. types assert, our brains are fluid and plastic. We’re learning that evolution can be a more rapid process than we thought. It doesn’t take hundreds of thousands of years to produce genetic alterations.

Moreover, we’ve evolved to adapt to diverse environments. Different circumstances can selectively activate different genetic potentials. Individual behavior can vary wildly from one context to another. An arrogant bully on the playground may be meek in math class. People have kaleidoscopic thinking styles and use different cognitive strategies to solve the same sorts of problems.

Evolutionary psychology leaves the impression that human nature was carved a hundred thousand years ago, and then history sort of stopped. But human nature adapts to the continual flow of information—adjusting to the ancient information contained in genes and the current information contained in today’s news in a continuous, idiosyncratic blend.
Sharon Begley's account, in my view, was not overdrawn, it was overdue. Re "Spent" - this sounds-like forgettable book takes evolutionary psychology to the shopping mall to show what we are genetically "hardwired" to buy and why, according to six (count 'em) big traits.

The book might have made a bigger splash before the recession hit. To listen to local retailers wail, many people just now have hardwired their wallets to their pockets. But surely Pleistocene cave men did the same thing, so there must be a module for that too somewhere in there ...

Essentially, two things killed evolutionary psychology: Neuroplasticity, as Brooks notes, and Occam's Razor. It's never been clear that EPs' selfish genes and brain modules ever existed, or ever needed to. Evolutionary psychologists keep looking for things that their current interpretation of human evolution can explain - which is to say, anything and everything, provided speculation is freely allowed.

Hat tip: Stephanie West Allen at Brains on Purpose