Source analysis of the N170 to faces and objects.

To clarify the neural sources for the face-sensitive N170, ERPs were recorded in 16 subjects viewing upright and inverted faces, and compared to seven object categories. Source analyses were performed for each category and each subject at the latency of the N170. Larger source intensities were found in the posterior superior temporal sulcus region (STS) for faces compared to objects. STS intensities were highly correlated to the N170 amplitude over both hemispheres only for faces. The results suggest that one of the major sources of the N170 is the STS region and that the larger N170 amplitude to inverted faces is due to increased activation of that source for inverted faces rather than a recruitment of additional areas. Copyright 2004 Lippincott Williams and Wilkins