Dynamic brain activation patterns for face recognition: a magnetoencephalography study

The present study used magnetoencephalography (MEG) to investigate the spatiotemporal profile of neurophysiological activity associated with recognition of recently encountered human faces in seventeen healthy right-handed adults. Activity sources modeled as instantaneous equivalent current dipoles were found in ventral occipito-temporal regions during the early stages of stimulus processing and in lateral temporal cortices during later stages. Hemispheric asymmetries in regional activity were restricted to ventral occipitotemporal areas. The magnitude of magnetic flux originating in these regions was greater in the right hemisphere during the first 350 ms post-stimulus onset. In addition, the duration of neurophysiological activity was greater in the right hemisphere after 600 ms post-stimulus onset. The results indicate right hemisphere predominance in the degree of engagement of neurophysiological processes involved in both the pre- and post-recognition phases of face processing.