Imagine not being able to recognize your spouse in a crowd of faces or forgetting what your own child looks like. Although this may sound like an episode of The Twilight Zone, for some people, such surreal events occur every day. Also known as face blindness, prosopagnosia—the inability to recognize faces—may affect up to 2 percent of the population. Brain injury can trigger face blindness and, for reasons that are unclear, the condition is present in some people from birth.
Research by HMS cognitive neuroscientist Beatrice de Gelder and other investigators is shedding light on this intriguing disorder. One recent study, for example, suggests that smiles, scowls, and other emotional expressions may help prosopagnosics better recognize faces. De Gelder and her colleagues found that emotionally expressive faces activated certain areas in the brains of lifelong prosopagnosics, while neutral faces did not.
“Such findings suggest,” de Gelder says, “that emotional information may play an important role in the way we process faces.”
Elissa Ely ’88 is a psychiatrist at the Massachusetts Mental Health Center.