The role of early visual cortex in visual short-term memory and visual attention.
We measured cortical activity with functional magnetic resonance imaging to probe the involvement of early visual cortex in visual short-term memory and visual attention. In four experimental tasks, human subjects viewed two visual stimuli separated by a variable delay period. The tasks placed differential demands on short-term memory and attention, but the stimuli were visually identical until after the delay period. Early visual cortex exhibited sustained responses throughout the delay when subjects performed attention-demanding tasks, but delay-period activity was not distinguishable from zero when subjects performed a task that required short-term memory. This dissociation reveals different computational mechanisms underlying the two processes.
Offen
Shani
S
Center for Neural Science, New York University, New York, 10003, USA. shani@cns.nyu.edu
Schluppeck
Denis
D
Heeger
David J
DJ
D001288:Attention / Q000502:physiology*; D001931:Brain Mapping / Q000379:methods; D003463:Cues; D004192:Discrimination, Psychological / Q000502:physiology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008570:Memory, Short-Term / Q000502:physiology*; D010364:Pattern Recognition, Visual / Q000502:physiology*; D010775:Photic Stimulation / Q000379:methods; D011601:Psychophysics; D014793:Visual Cortex / Q000502:physiology*