Face-selective processing in human extrastriate cortex around 120 ms after stimulus onset revealed by magneto- and electroencephalography.
Quick recognition of faces is crucial to a variety of human interactions, and highly specialized pathways may be involved in the processing of faces. To reveal selectivity to faces in early cortical processing, whole-scalp magnetoencephalography (MEG) and electroencephalography (EEG) were used to record event-related responses to faces and degraded faces and their inverted counterparts. We observed increases in the peak latency and amplitude of the early 120-ms component (P120) for the inverted faces. These effects were enhanced for the 1 70-ms component (N170). For the degraded counterparts, a significant effect of the inversion was observed only for the N170, which was strongly delayed. Source modelling suggested that the early response originated at the posterior occipital areas whereas the later response was generated anterior and lateral to this location. We conclude that under sufficiently good conditions face-selective activity may be taking place during the P120.
Linkenkaer-Hansen
K
K
BioMag Laboratory, Medical Engineering Centre, Helsinki University Central Hospital, Finland. klaus@biomag.helsinki.fi
Palva
J M
JM
Sams
M
M
Hietanen
J K
JK
Aronen
H J
HJ
Ilmoniemi
R J
RJ
D001931:Brain Mapping / Q000379:methods; D004569:Electroencephalography; D005145:Face / Q000502:physiology; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D015225:Magnetoencephalography; D008297:Male; D010364:Pattern Recognition, Visual / Q000502:physiology*; D010775:Photic Stimulation / Q000379:methods*; D013997:Time Factors; D014793:Visual Cortex / Q000502:physiology*; D014795:Visual Pathways / Q000502:physiology; D014796:Visual Perception / Q000502:physiology