Hart Publishes Study On Brain Reactions To Race
By by KELLY SMITH, Contributing Writer
The brains of black people and white people exhibit a different reaction to members of other races than to their own, according to a study conducted by Associate Professor of Psychology Allen Hart '82.

The study was conducted using magnetic resonance imaging (MRI) to measure the effects of 30 grayscale images of white faces and 30 grayscale images of black faces on the amygdala, a cluster of nerves in the brain that is often linked with emotion, memory and learning.

The subjects for the experiment were four people who identified themselves as white and four who identified themselves as black.

In the study, published in the August edition of NeuroReport, Hart and his colleagues demonstrated their finding that brain activity in the amygdala responds more actively in white viewers presented with black faces and vice versa than in viewers presented with faces from members of their own race. The study referred to someone from another race as an "outgroup" and someone from the same race as an "ingroup."

In the study, Hart also noticed that "subjects [were] better able to recognize previously presented ingroup faces compared to previously presented outgroup faces."

The study relied on neuroimaging to detect the differences in brain activity, specifically the flow of blood to regions of the brain.

During the first trial of the experiment there was no perceivable difference of reaction to racial differences in the photographs, according to the study. This result is to be expected because the amygdala reacts to unfamiliar images, according to the study.

But during the second scan, as subjects viewed pictures they had seen before, their amygdala activity was noticeably higher when confronted with a face from a member of an outgroup, suggesting that subjects became familiar with members of their own race more rapidly than those of the other group.

The study did not find any noticeable differences in amygdala activation between images of opposite genders, according to Hart.

After the experiment, the subjects were interviewed for their subjective response to the images.

"When asked to describe any subjective feelings to these stimuli, subjects unanimously reported that they had no strong emotional reaction to the stimuli in general," wrote Hart in the study. "And, more specifically, they noted no difference in their emotional reaction to the outgroup versus ingroup stimuli."

Although Hart's study included a warning "not to draw premature conclusions" from the results, he also wrote that "perhaps the present results have implications for racial stereotyping."

Hart collaborated on the study with Scott Rauch '82, his roommate of three years while they were both students at Amherst. Fifteen years after graduating, the two met at a class reunion. Hart had become a social psychologist and professor at Amherst while Rauch became a psychiatrist at Massachusetts General Hospital in Boston. At the reunion, the two started talking and discovered that some of their interests in psychology converged.

Hart was interested in the effect of perceived racial differences in situations when race would seem to be irrelevant to the perceiver.

Rauch, who is the director of psychological neuroimaging research at Massachusetts General, had experience with the neuroimaging process that would allow for the study of such a phenomenon. During this reunion the two developed the primary model for the study.

Emily Shore '99 and Ying Yu '99 were two of Hart's research assistants and ran a number of preliminary studies leading up to the final project. Hart, Rauch and colleagues Paul Whalen, Lisa Shin, Sean McInerney and Håkan Fischer completed the study during Hart's sabbatical over the past year and published their work in last May.

One of the most noteworthy aspects of this study, according to Hart, is the innovative movement the researchers made toward an interdisciplinary collaboration of social psychology, neuroimaging and psychiatry.

Hart said that the collaboration proves "it is possible to really do interdisciplinary work across three very disparate fields."

"Really, the most exciting aspect of the work is the bringing together of social psychology and neuroscience," said Rauch.

Commenting on the impact the study may have on the social and scientific worlds, Hart says that his work "has opened the door and we don't really know what's on the other side."

One of the key results of his work is implications it could have as a source of error in past and future psychological research.

In the NeuroReport article, Hart wrote that his team concluded "that researchers seeking to study brain responses to face stimuli in human subjects should consider the relationship between the race of subjects and stimuli as a significant potential source of variation."

Hart said that he sees the results of his study more as a starting point for further research than as a conclusion.

"[The study] doesn't answer a lot of questions," said Hart. Instead, he said, it "poses a lot of questions."

"I think it's really premature to draw relationships between stereotypes and our findings," added Rauch.

Hart said that he is interested in doing further research on the neural effects of race perception, including efforts to expand the number of subjects used in the study, incorporate more races, and examine the members of other cultures where race plays a different social role.

Issue 02, Submitted 2000-09-13 16:10:32