The many faces of the gamma band response to complex visual stimuli.
While much is known about the functional architecture of the visual system, little is known about its large-scale dynamics during perception. This study describes this dynamics with a high spatial, temporal and spectral resolution. We recorded depth EEG of epileptic patients performing a face detection task and found that the stimuli induced strong modulations in the gamma band (40 Hz to 200 Hz) in selective occipital, parietal and temporal sites, in particular the fusiform gyrus, the lateral occipital gyrus and the intra-parietal sulcus. Occipito-temporal sites were the first to be activated, closely followed by the parietal sites, while portions of the primary visual cortex seemed to deactivate temporarily. Some of those effects were found to be correlated across distant sites, suggesting that a coordinated balance between regional gamma activations and deactivations could be involved during visual perception.
Lachaux
Jean-Philippe
JP
Laboratoire de Neurosciences Cognitives et Imagerie Cérébrale (LENA), CNRS URA 654, Hôpital de La Salpêtrière, 47 Bd de l'Hôpital, 75651 Paris cedex 13 Paris, France. lachaux@lyon.inserm.fr
George
Nathalie
N
Tallon-Baudry
Catherine
C
Martinerie
Jacques
J
Hugueville
Laurent
L
Minotti
Lorella
L
Kahane
Philippe
P
Renault
Bernard
B
D000328:Adult; D004569:Electroencephalography; D004827:Epilepsy / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D010775:Photic Stimulation / Q000379:methods; D014793:Visual Cortex / Q000503:physiopathology*; D014796:Visual Perception / Q000502:physiology*