Tuesday, November 15, 2011

Bad fMRI research

Consider an op-ed piece recently published in the New York Times, which used fMRI results to demonstrate, purportedly, that people "literally love their iPhones." The evidence? When the researchers showed subjects a video of a ringing cellphone, a part of the brain called the insula exhibited a spike in activity. Because previous studies have linked the insula with feelings of love, the authors concluded that the gadget had become a "romantic rival" for husbands and wives.

But here's the problem: The insula is also activated by feelings of disgust and bodily pain. It plays an important role in coordinating hand movement, maintaining balance and monitoring bodily changes. In fact, activity in the insula has been implicated in nearly a third of all fMRI papers. Because the brain is such a vast knot of connections, it's often impossible to understand what's happening based on local patterns of activity. Perhaps we're disgusted by our iPhones, or maybe the insula is just preparing the fingers to move. The pretty picture can't reveal the answer.

What's worse, the very fact that we're looking at a brain scan seems to inhibit our critical thinking. Deena Skolnick Weisberg, a psychologist at Temple University, has demonstrated that merely referencing fMRI research can bias the evaluation of scientific papers.

When she gave neuroscience students and ordinary adults a few examples of obviously flawed scientific explanations, people were consistently able to find the flaws. However, when these same explanations were prefaced with the phrase "Brain scans indicate," both the students and adults became much less critical.
--Jonah Lehrer, WSJ, on overinterpreting brain scans. HT: Franklin Shaddy