Selective attention increases the dependency of cortical responses on visual motion coherence in man.
Attention improves visual discrimination and consequently allows to discern stimuli with low signal-to-noise ratios that otherwise would remain undetected. We used magnetoencephalography (MEG) to test whether neuromagnetic responses recorded from occipito-temporal cortex, reflecting the size of visual motion signals embedded in noise (motion coherence), would mirror the perceptual changes induced by attention. Attention directed to a given hemifield increased and decreased the coherence modulation of the MEG response over contralateral and ipsilateral visual cortex, respectively, indicating a change in the neuronal signal-to-noise ratio at the population level.
Händel
Barbara
B
Department of General Neurology, University of Tübingen, 72076 Tübingen, Germany.
Lutzenberger
Werner
W
Thier
Peter
P
Haarmeier
Thomas
T
D000328:Adult; D001288:Attention / Q000502:physiology*; D002540:Cerebral Cortex / Q000502:physiology*; D003463:Cues; D005133:Eye Movements / Q000502:physiology; D005260:Female; D005403:Fixation, Ocular; D006801:Humans; D015225:Magnetoencephalography; D008297:Male; D009039:Motion Perception / Q000502:physiology*; D010775:Photic Stimulation; D011187:Posture; D013997:Time Factors; D015348:Vision, Binocular / Q000502:physiology; D055815:Young Adult