A functional MRI study of face recognition in patients with prosopagnosia.

An fMRI investigation was conducted to determine whether patients with impaired face recognition, a deficit known as prosopagnosia, would show functional activation in the fusiform gyrus, the neural substrate for face processing, when viewing faces. While the patients did show activation in the fusiform gyrus, with significantly more voxels in posterior areas than their control subjects, this activation was not sufficient for face processing. In one of the patients, the posterior activation was particularly evident in the left hemisphere, which is thought to be involved in feature-based strategies of face perception. We conclude that an increased reliance on feature-based processing in prosopagnosia leads to a recruitment of neurons in posterior regions of the fusiform gyrus, regions that are not ideally suited for processing faces.