A recent NY Times bit talks about “neurorealism,” that is, people’s increased tendency to believe psychological or other scientific assertions when those assertions are accompanied by images from brain scans. The piece quotes Deena Weisberg, who wrote an article in the Journal of Cognitive Neuroscience documenting this empirically (in both laypeople and, if I remember the article correctly, in experts, though to a lesser extent), and the neologizer, Eric Racine. The piece mentions a newspaper article “about how high-fat foods activate reward centers in the brain,” and asks, “Couldn’t we have proced that with a slice of pie and a piece of paper with a check box on it?” Brian Leiter also noted the Times piece, with a plug for his paper criticizing legal academics’ use of evolutionary biology.
But the Times bit, and these scholars, conflate two very different points. The first is the “credulousness” issue—that people believe the assertions when accompanied by brain images. That’s an important point, especially in the legal context, where judges, jurors, or policy-makers might be exposed to such scans and misled by such scientific “explanations” of behavior. (Of course, it’s not enormously surprising, given past concerns about jurors’ understanding of complex scientific evidence.)
But that’s quite a different point from the dismissive “check box” question, criticizing even the usefulness of such neurological research. fMRI and other such scans can of course provide important and useful evidence, and certainly can tell us more than simple self-reports or even other behavioral studies. Matt Lieberman, a psychologist at UCLA [disclosure: we were in grad school together] and one of those most prominently associated with the newish field of social cognitive neuroscience, has addressed this well, in answering whether SCN provides something more than conventional social psychology. Summarizing just one of his papers on the issue: he points out that fMRI can provide evidence that “two psychological processes that experientially feel similar and produce similar behavioral results, but actually rely on different underlying mechanisms,” such as memory for social and non-social information. It can document “processes that one would not think rely on the same mechanisms, when in fact they do,” such as the common neurological pathways in the experience of both physical and social pain. And more speculatively, he suggests, as “more is learned about the precise functions of different regions of the brain it may be possible to infer some of the mental processes that an individual is engaged in just from looking at the activity of their brains.” This is an important advantage to overcome potential difficulties in, for instance, self-report.
There is of course danger in over-selling fMRI and similar neurological evidence—whether evaluating psychiatric patients, capital defendants, or others—and documenting people’s susceptibility to such over-sell is important. But it’s quite a different question whether such scans can be useful, and to dismiss them out of hand is just as obviously a mistake.