Early electrophysiological correlates of adaptation to personally familiar and unfamiliar faces across viewpoint changes.

Behavioral studies have shown that matching individual faces across depth rotation is easier and faster for familiar than unfamiliar faces. Here we used event-related potentials (ERPs) to clarify the locus of this behavioral facilitation, that is whether it reflects changes at the level of perceptual face encoding, or rather at later stages of processing. We used an identity adaptation paradigm in ERPs, during which a first (adapting) face (~3000 ms) rotated 30° in depth was followed by a second full front face (200 ms) which was either the same or a different identity as the first face.

Early adaptation to repeated unfamiliar faces across viewpoint changes in the right hemisphere: evidence from the N170 ERP component.

Event-related potential (ERP) studies have shown that sensitivity to individual faces emerges as early as approximately 160ms in the human occipitotemporal cortex (N170). Here we tested whether this effect generalizes across changes in viewpoint. We recorded ERPs during an unfamiliar individual face adaptation paradigm.

The time course of the inversion effect during individual face discrimination.

Human faces look more similar to each other when they are presented upside down, leading to an increase in error rate and response time during individual face discrimination tasks. This face inversion effect (FIE) is one of the most robust findings in the face processing literature. Recent neuroimaging studies using adaptation to face identity have shown that the "fusiform face area" was the primary neural source of the behavioral FIE.