Autori: Teodora Gliga and Ghislaine Dehaene-Lambertz1-

Editorial: Cognition, 2006.

Rezumat:

Do infants perceive visual cues as diverse as frontal-view faces, profiles or bodies
as being different aspects of the same object, a fellow human? If that is the case,
visual exposure to one such cue should facilitate the subsequent processing of the
others. To verify this hypothesis, we recorded event-related responses in fourmonth
old infants and in adults. Pictures of eyes were interleaved amongst images
belonging to three human contexts (frontal-view faces, profiles or bodies) or nonhuman
contexts (houses, cars or pliers). In adults, both profile and frontal face
contexts elicited suppression of the N170 response to eye pictures, indicating an
access to a view-invariant representation of faces. In infants, a response
suppression of the N290 component was recorded only in the context of frontal
faces, while profile context induces a different effect (i.e. a P400 enhancement) on
eye processing. This dissociation suggests that the view-invariant representation of
faces is learned, as it is for other 3-D objects and needs more than four months of
exposure to be established. In a follow-up study, where infants were exposed to a
short movie showing people rotating their heads, the profile-induced P400 effect
was speeded up, indicating that exposure to successive views of the same object is
probably a way to build up adult-like face representations.

Cuvinte cheie: infant face perception, view-invariance, response suppression, ERPs, N170

URL: http://www.cbcd.bbk.ac.uk/people/teo/gliga_cognition.pdf