Nancy Kanwisher, a professor at MIT’s McGovern Institute for Brain Research, is enlivening a scientific debate about the architecture of the mind that has gone on for 200 years: Is the brain a general-purpose organ adept at juggling myriad cognitive tasks, or is it modular, with distinct regions specializing in certain functions, such as face recognition or language? She has made a compelling case for the latter theory.
Over the past decade or so, Kanwisher has identified small but distinct regions in the brain dedicated to specific tasks. She is best known for verifying the existence of the fusiform face area (FFA), a region that hones in on and recognizes faces. The finding helped explain why people with damage to this area of the brain cannot recognize faces, even those of people they know well.
“A number of functions, including some that we suspected and some that we never would have guessed, are really stunningly specialized,” says Kanwisher. She and her colleagues were amazed to discover, for example, another module — the parahippocampal place area (PPA) — dedicated to processing places. They also identified a region close to but distinct from the FFA that specializes in recognizing bodies.
Kanwisher’s experiments use functional magnetic resonance imaging (fMRI), a brain-scanning technology that since the early 1990s has enabled remarkable discoveries in cognitive science. Its vivid scans of the brain in action enable Kanwisher to observe specialized regions that light up consistently as subjects respond to associated stimuli. She notes, however, that while such experiments have provided solid evidence for cognitive specialization, they have so far uncovered only a handful of brain regions tied to specific tasks.
“I don’t think everything’s localized in its private little oval in the brain — I think these functions are the minority cases in cognition,” she says. Armed with these insights about the architecture of the mind, Kanwisher has embarked on an ambitious study of autism supported by the Ellison Medical Foundation. The project will test a large number of autistic children on an array of behavioral tasks that reflect recent advances in the understanding of cognition.
“I hope to really turbocharge the serious scientific investigation of what autism is,” says Kanwisher. “I think it is fundamentally a cognitive disorder. If you want to understand why autistic people show these features of repetitive motions, language disorders, and social communication disorders, the first thing you think is, ‘OK, there are some cognitive deficits.’”
Some of these deficits are associated with brain regions that are functionally specific. So Kanwisher will investigate, for example, whether there is a link between social communication disorders in autism and a brain region dedicated to “theory of mind,” or perceiving other people’s thoughts, which was discovered by her colleague Rebecca Saxe.
In an important aspect of the study, she is collaborating with brain-imaging experts at Massachusetts General Hospital to “revolutionize pediatric neuroimaging.” Being scanned with an fMRI machine requires subjects to lie very still for substantial stretches of time, which is difficult for children. To address that challenge, the research team is developing new, ultra-high-resolution measuring devices that can compensate for head movement and allow shorter scans.
As someone who began her career before the widespread use of neuroimaging technology in research, Kanwisher appreciates her ready access to state-of-the-art fMRI. Her work equally benefits, she says, from the expertise of her colleagues at MIT. “I’m a psychologist doing cognitive work, so I need serious cognitive scientists as colleagues. At the same time, I need neuroscientists — people who know about brains. I don’t think anybody can top our department for a combination of the best in cognitive science plus really good neuroscience. There’s no place in the world I’d rather be.”