Interaction between the electrical stimulation of a face-selective area and the perception of face stimuli.

We electrically stimulated the face-selective area in epileptic patients while they were performing a face-categorization task. Face categorization was interfered by electrical stimulation but was restored by increasing the visual signal. More importantly, face-categorization interference by electrical stimulation was confined to face-selective electrodes, and the amount of interference was positively correlated with the sensitivity of the face-selective electrodes. These results strongly support the hypothesis that the face-selective area has a direct causal link to face perception.