PASCAL - Pattern Analysis, Statistical Modelling and Computational Learning

The M170 Reflects a Viewpoint-Dependent Representation for Both Familiar and Unfamiliar Faces
Michael Ewbak, Will Smith, Edwin Hancock and Tim Andrews
Cerebral Cortex Volume 18, Number 2, pp. 364-370, 2007. ISSN 1047-3211


The aim of this study was to determine the extent to which the neural representation of faces in visual cortex is viewpoint dependent or viewpoint invariant. Magnetoencephalography was used to measure evoked responses to faces during an adaptation paradigm. Using familiar and unfamiliar faces, we compared the amplitude of the M170 response to repeated images of the same face with images of different faces. We found a reduction in the M170 amplitude to repeated presentations of the same face image compared with images of different faces when shown from the same viewpoint. To establish if this adaptation to the identity of a face was invariant to changes in viewpoint, we varied the viewing angle of the face within a block. We found a reduction in response was no longer evident when images of the same face were shown from different viewpoints. This viewpoint-dependent pattern of results was the same for both familiar and unfamiliar faces. These results imply that either the face-selective M170 response reflects an early stage of face processing or that the computations underlying face recognition depend on a viewpoint-dependent neuronal representation.

EPrint Type:Article
Project Keyword:Project Keyword UNSPECIFIED
Subjects:Machine Vision
Brain Computer Interfaces
ID Code:3891
Deposited By:Edwin Hancock
Deposited On:25 February 2008