Intersubject synchronization of cortical activity during natural vision.
To what extent do all brains work alike during natural conditions? We explored this question by letting five subjects freely view half an hour of a popular movie while undergoing functional brain imaging. Applying an unbiased analysis in which spatiotemporal activity patterns in one brain were used to "model" activity in another brain, we found a striking level of voxel-by-voxel synchronization between individuals, not only in primary and secondary visual and auditory areas but also in association cortices. The results reveal a surprising tendency of individual brains to "tick collectively" during natural vision. The intersubject synchronization consisted of a widespread cortical activation pattern correlated with emotionally arousing scenes and regionally selective components. The characteristics of these activations were revealed with the use of an open-ended "reverse-correlation" approach, which inverts the conventional analysis by letting the brain signals themselves "pick up" the optimal stimuli for each specialized cortical area.
Hasson
Uri
U
Department of Neurobiology, Weizmann Institute of Science, Rehovot 76100, Israel.
Nir
Yuval
Y
Levy
Ifat
I
Fuhrmann
Galit
G
Malach
Rafael
R
D000328:Adult; D001288:Attention; D001303:Auditory Cortex / Q000502:physiology; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000502:physiology*; D004644:Emotions; D005145:Face; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009040:Motion Pictures; D009778:Occipital Lobe / Q000502:physiology; D010775:Photic Stimulation; D013702:Temporal Lobe / Q000502:physiology; D014785:Vision, Ocular; D014793:Visual Cortex / Q000502:physiology*; D014796:Visual Perception