How the brain responds to and processes images of people from different racial groups is an emerging field of investigation that could have major implications for society. Psychologist Elizabeth Phelps of New York University, in New York, who in 2000 led one of the first studies in this area, tells Nature what her latest review of the field reveals about the neuroscience of race1.
What does psychology tell us about race?
Social psychologists differentiate between the attitudes that people express and their implicit preferences. This can be studied using the implicit association task, which measures initial, evaluative responses. It involves asking people to pair concepts such as black and white with concepts like good and bad. What you find is that most white Americans take longer to make a response that pairs black with good and white with bad than vice versa. This reveals their implicit preferences.
What did your review of the neuroscience literature show?
My colleagues and I found that there’s a network of brain regions that is consistently activated in neuroimaging studies of race processing. This network overlaps with the circuits involved in decision-making and emotion regulation, and includes the amygdala, fusiform face area (FFA), anterior cingulate cortex (ACC) and dorsolateral prefrontal cortex (DLPFC).
What did your previous work show?
Our 2000 study was the first to link race preference to brain activity. We measured the eye-blink startle, a reflex response that people display when they hear a loud noise, for example. A lot of studies have shown that this reflex is potentiated [enhanced] when people are anxious or in the presence of something they think is negative. We found that implicit preferences were correlated with potentiated startle, and that both were correlated with the amount of amygdala activation.