When Doris Tsao first coaxed monkeys into an functional MRI (fMRI) scanner to watch their brains respond to images of faces, she saw blood flow increase in several regions of the brain. She and her colleagues used the blurry blobs of neural activity indicated by the fMRI scan to guide more precise studies. To the team’s surprise, those experiments revealed that there were six distinct regions of the brain dedicated to processing information about faces. Tsao called these face patches.
Over the last decade, her lab has learned that these face patches work together to recognize and discriminate between faces, and revealed computational strategies the cells use to accomplish this task. Her team has identified neurons that respond specifically to certain facial features, such as hair thickness or iris size, and found cells that respond selectively to the faces of only a few individuals.
Her group’s work on the primate face-processing system is part of her larger goal of understanding how the brain represents objects. Tsao is now planning new research to examine the neural circuitry that integrates discrete visual features into the perception of whole objects.