Article

People with congenital prosopagnosia (CP) report difficulty recognising faces in
everyday life and perform poorly on face recognition tests.
Here, we investigate
whether impaired adaptive face space coding might contribute to poor face
recognition in CP. To pinpoint how adaptation may affect face processing, a group
of CPs and matched controls completed two complementary face adaptation tasks:
the figural aftereffect, which reflects adaptation to general distortions of
shape, and the identity aftereffect, which directly taps the mechanisms involved
in the discrimination of different face identities.
CPs displayed a typical
figural aftereffect, consistent with evidence that they are able to process some
shape-based information from faces, e.g., cues to discriminate sex. CPs also
demonstrated a significant identity aftereffect. However, unlike controls, CPs
impression of the identity of the neutral average face was not significantly
shifted by adaptation, suggesting that adaptive coding of identity is abnormal in
CP. In sum, CPs show reduced aftereffects but only when the task directly taps
the use of face norms used to code individual identity.
This finding of a reduced
face identity aftereffect in individuals with severe face recognition problems is
consistent with suggestions that adaptive coding may have a functional role in face recognition.
CI - Copyright (c) 2011 Elsevier Ltd. All rights reserved.

Langue : ANGLAIS