A couple of years ago, a friend asked me to be a pilot subject for one of her fMRI studies. I immediately said yes, in large part because most of the psychologists I knew had their brains scanned at one time or another, and I was feeling left out. It was a tedious experience, involving the memorization of long strings of numbers—and being inside a magnet is like being buried alive, only louder. So when I emerged from the machine an hour later, I was grouchy.
But then she took me to a screen and showed me a record of my brain at work. It made up for the hour of torment. I was entranced.
Newspapers, magazines, TV and blogs very often discuss psychology these days as a series of studies that involve some measure of neural activity, usually fMRI. The most compelling studies are those which probe the brain while the subject is made to think about something controversial, such as politics, sports teams, race, sex, corporate brands or morality. It makes for great press releases. But fMRI imagery has attained an undue influence, and we shouldn’t be seduced.
“For both the novices and the experts, the presence of a bit of apparently-hard science turned bad explanations into satisfactory ones.”
There is nothing inherently wrong with imaging research. The best imaging studies inform psychological theory in a significant way. One elegant study, for instance, done by Stanislas Deheane, Elizabeth Spelke and their colleagues, found that different parts of the brain are active during exact arithmetic versus approximate arithmetic, supporting the theory that these aspects of numerical reasoning are psychologically distinct. More recently, Joshua Greene and his colleagues did a neat series of studies looking at the involvement of various brain areas, particularly those involving emotion and cognitive control, when people are confronted with different sorts of moral predicaments. This is more than just phrenology. But it is not so dazzling that it should usurp other areas of research.
FMRI studies—which indirectly measure the flow of oxygenated blood in the brain—are typically motivated by earlier experiments that used more conventional methods, and are not always a better window to the soul than eye tracking, behavioral genetics, implicit priming or dozens of other well-worn techniques. We know far more about the mind from the study of, say, reaction times than we do from fMRI studies.
Psychologists can be heard grousing that the only way to publish in Science or Nature is with pretty color pictures of the brain. The media, critical funding decisions, precious column inches, tenure posts, science credibility and the popular imagination have all been influenced by fMRI’s seductive but deceptive grasp on our attentions. It’s a pervasive influence, and it’s not because the science is better.
Why does it affect us so? Probably because fMRI seems more like real science than many of the other things that psychologists are up to. It has all the trappings of work with great lab-cred: big, expensive, and potentially dangerous machines, hospitals and medical centers, and a lot of people in white coats. In a recent study, Deena Skolnick, a graduate student at Yale, asked her subjects to judge different explanations of a psychological phenomenon. Some of these explanations were crafted to be awful. And people were good at noticing that they were awful—unless Skolnick inserted a few sentences of neuroscience. These were entirely irrelevant, basically stating that the phenomenon occurred in a certain part of the brain. But they did the trick: For both the novices and the experts (cognitive neuroscientists in the Yale psychology department), the presence of a bit of apparently-hard science turned bad explanations into satisfactory ones.
We’re also natural dualists. We intuitively think of ourselves as non-physical, and so it is a shock, and endlessly interesting, to see our brains at work in the act of thinking. Young children are explicit about the duality; they will tell you that you need your brain for certain activities, such as doing a math problem, but not for others, such as loving your brother or pretending to be a kangaroo. And most of us, children and adults, are comfortable with the idea that though our bodies will die, our minds (consciousness, memory, will) can survive.
So, when a New York Times article rhapsodized about neural correlates of passion (“Watching New Love As It Sears the Brain”), the interest of the article for the average reader did not lie in the details about the role of the caudate nucleus. Rather, it lay in the fact that the brain is involved at all in anything as interesting and personal as falling in love.
But we know, scientifically, that the physical activity of the brain is the source of our mental processes. It’s one of the first things the professor says in any intro psych course: The mind is what the brain does, and so every mental event, from falling in love to worrying about your taxes, is going to show up as a brain event. In fact, if anyone were to find an aspect of thought that did not correspond to a brain event, it would be the discovery of the century, as it would be the first ever proof of hardcore Cartesian dualism.
Despite this most concrete of scientific understandings, however, intuition tells us that our minds and our brains are very different things. The pretty pictures of our brain at work will continue to seduce us in many insidious ways, and provide my colleagues in cognitive neuroscience the enviable advantage of, at the very least, being able to inspire awe.
—Paul Bloom is a professor of psychology at Yale University and the author of Descartes’ Baby: How the Science of Child Development Explains What Makes Us Human.
Originally published June 26, 2006