Friday, January 30, 2009

Why neuroeconomics is not yet a science

Jeff Goldberg undergoes an fMRI which reminds me as to why neuroeconomics has been overselling itself:
Bin Laden, I was pleased to learn, stimulated predictably negative brain activity, but the neuroscientists were flummoxed by my reaction to the sight of Ahmadinejad, who apparently stimulated, in a most dramatic way, my ventral striatum. “Reward!” Iacoboni said. “You’ll have to explain this one.”

When I couldn’t, Joshua Freedman, who is a practicing psychiatrist, offered a possible explanation: “Perhaps you believe that the Israelis or the Americans have the situation under control and so you’re anticipating the day that he’s brought down.” He asked me some questions about my view of Jewish history, and then said: “You seem to believe that the Jewish people endure, that people who try to hurt the Jewish people ultimately fail. Therefore, you derive pleasure from believing that Ahmadinejad will also eventually fail. It’s very similar to the experiment with the monkey and the grape. It’s been shown that the monkey feels maximal reward not when he eats the grape but at the moment he’s sure it’s in his possession, ready to eat. That could explain your response to Ahmadinejad.”

He paused. “Or it means that you’re a Shiite.”

Andrew Gelman addresses the problems of multi comparisons and the overhyped "voodoo" correlations of neuroscience in the press.
It's hard for me to believe that the approach based on separate analyses of voxels and p-values, is really the best way to go. The null hypothesis of zero correlations isn't so interesting. What's really of interest is the pattern of where the differences are in the brain. ...

I think the way forward will be to go beyond correlations and the horrible multiple-comparisons framework, which causes so much confusion. Vul et al. and Lieberman et al. both point out that classical multiple comparisons adjustments do not eliminate the systematic overstatement of correlations.

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