Exploring the functional architecture of person recognition system with event-related potentials in a within- and cross-domain self-priming of faces.

In this paper, we explored the functional properties of person recognition system by investigating the onset, magnitude, and scalp distribution of within- and cross-domain self-priming effects on event-related potentials (ERPs). Recognition of degraded pictures of famous people was enhanced by a prior exposure to the same person's face (within-domain self-priming) or name (cross-domain self-priming) as compared to those preceded by neutral or unrelated primes. The ERP results showed first that the amplitude of the N170 component to famous face targets was modulated by within- and cross-domain self-priming, suggesting not only that the N170 component can be affected by top-down influences but also that this top-down effect crosses domains.

Perception of facial expressions and voices and of their combination in the human brain.

Using positron emission tomography we explored brain regions activated during the perception of face expressions, emotional voices and combined audio-visual pairs. A convergence region situated in the left lateral temporal cortex was more activated by bimodal stimuli than by either visual only or auditory only stimuli. Separate analyses for the emotions happiness and fear revealed supplementary convergence areas situated mainly anteriorly in the left hemisphere for happy pairings and in the right hemisphere for fear pairings indicating different neuro-anatomical substrates for multisensory integration of positive versus negative emotions.

Stepwise emergence of the face-sensitive N170 event-related potential component.

The present study used a parametric design to characterize early event-related potentials (ERP) to face stimuli embedded in gradually decreasing random noise levels. For both N170 and the vertex positive potential (VPP) there was a linear increase in amplitude and decrease in latency with decreasing levels of noise. In contrast, the earlier visual P1 component was stable across noise levels.

Is the N170 for faces cognitively penetrable? Evidence from repetition priming of Mooney faces of familiar and unfamiliar persons.

Impoverished images of faces, two-tone Mooney faces, severely impair the ability to recognize to whom the face pertains. However, previously seeing the corresponding face in a clear format helps fame-judgments to Mooney faces. In the present experiment, we sought to demonstrate that enhancement in the perceptual encoding of Mooney faces results from top-down effects, due to previous activation of familiar face representation.

The functionally defined right occipital and fusiform "face areas" discriminate novel from visually familiar faces.

Neuroimaging (PET and fMRI) studies have identified a set of brain areas responding more to faces than to other object categories in the visual extrastriate cortex of humans. This network includes the middle lateral fusiform gyrus (the fusiform face area, or FFA) as well as the inferior occipital gyrus (occipital face area, OFA). The exact functions of these areas in face processing remain unclear although it has been argued that their primary function is to distinguish faces from nonface object categories-"face detection"-or also to discriminate among faces, irrespective of their visual familiarity to the observer.

Differential involvement of episodic and face representations in ERP repetition effects.

The purpose of this study was to disentangle the contribution of episodic-perceptual from pre-existing memory representations of faces to repetition effects. ERPs were recorded to first and second presentations of same and different photos of famous and unfamiliar faces, in an incidental task where occasional non-targets had to be detected. Repetition of same and different photos of famous faces resulted in an N400 amplitude decrement.