Visual face identification requires distinguishing between thousands of faces we know. This computational feat involves a network of brain regions including the fusiform face area (FFA) and anterior inferotemporal cortex (aIT), whose roles in the process are not well understood. Here, we provide the first demonstration that it is possible to discriminate cortical response patterns elicited by individual face images with high-resolution functional magnetic resonance imaging (fMRI). Response patterns elicited by the face images were distinct in aIT but not in the FFA. Individual-level face information is likely to be present in both regions, but our data suggest that it is more pronounced in aIT. One interpretation is that the FFA detects faces and engages aIT for identification.fMRI ͉ information-based ͉ population code W hen we perceive a familiar face, we usually effortlessly recognize its identity. Identification requires distinguishing between thousands of faces we know. A puzzle to both brain and computer scientists, this computational feat involves a network of brain regions (1) including the fusiform face area (FFA) (2, 3) and anterior inferotemporal cortex (aIT) (4). There is a wealth of evidence for an involvement in face identification of both the FFA (1, 5-18) and aIT (4,16,(19)(20)(21)(22)(23)(24)(25)(26).The FFA responds vigorously whenever a face is perceived (2,3,27). This implies that the FFA distinguishes faces from objects of other categories and suggests the function of face detection (27,28). An additional role for the FFA in face identification has been suggested by three lines of evidence: (i) Lesions in the region of the FFA are frequently associated with deficits at recognizing individual faces (prosopagnosia) (6, 9, 10). (ii) The FFA response level covaries with behavioral performance at identification (11). (iii) The FFA responds more strongly to a sequence of different individuals than to the same face presented repeatedly (8,(12)(13)(14)(15)(16)(17).For aIT as well, human lesion and neuroimaging studies suggest a role in face identification. Neuroimaging studies (4,(22)(23)(24)26) found anterior temporal activation during face recognition with the activity predictive of performance (22). Lesion studies (19,20,25) suggest that right anterior temporal cortex is involved in face identification. In monkey electrophysiology, in fact, face-identity effects appear stronger in anterior than in posterior inferotemporal cortex (29-31).These lines of evidence suggest an involvement of both the FFA and aIT in face identification. A region representing faces at the individual level should distinguish individual faces by its activity pattern. However, it has never been directly demonstrated that either the FFA or aIT responds with distinct activity patterns to different individual faces.We therefore investigated response patterns elicited by two face images by means of high-resolution functional magnetic resonance imaging (fMRI) at 3 Tesla (voxels: 2 ϫ 2 ϫ 2 mm 3 ). We asked whether response pattern...