When the brain loses its self: prefrontal inactivation during sensorimotor processing.
A common theme in theories of subjective awareness poses a self-related "observer" function, or a homunculus, as a critical element without which awareness can not emerge. Here, we examined this question using fMRI. In our study, we compared brain activity patterns produced by a demanding sensory categorization paradigm to those engaged during self-reflective introspection, using similar sensory stimuli. Our results show a complete segregation between the two patterns of activity. Furthermore, regions that showed enhanced activity during introspection underwent a robust inhibition during the demanding perceptual task. The results support the notion that self-related processes are not necessarily engaged during sensory perception and can be actually suppressed.
Goldberg
Ilan I
II
Department of Neurobiology, Weizmann Institute of Science, Rehovot 76100, Israel.
Harel
Michal
M
Malach
Rafael
R
D000161:Acoustic Stimulation; D000328:Adult; D001931:Brain Mapping; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D010775:Photic Stimulation; D017397:Prefrontal Cortex / Q000502:physiology*; D012649:Self Concept