Modulation of oscillatory neuronal synchronization by selective visual attention.
In crowded visual scenes, attention is needed to select relevant stimuli. To study the underlying mechanisms, we recorded neurons in cortical area V4 while macaque monkeys attended to behaviorally relevant stimuli and ignored distracters. Neurons activated by the attended stimulus showed increased gamma-frequency (35 to 90 hertz) synchronization but reduced low-frequency (<17 hertz) synchronization compared with neurons at nearby V4 sites activated by distracters. Because postsynaptic integration times are short, these localized changes in synchronization may serve to amplify behaviorally relevant signals in the cortex.
Laboratory of Neuropsychology, National Institute of Mental Health, National Institutes of Health, Building 49, Room 1B80, 9000 Rockville Pike, Bethesda, MD 20892-4415, USA. fries@ln.nimh.nih.gov
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Fries
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Reynolds
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Rorie
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Desimone
D000200:Action Potentials; D000818:Animals; D001288:Attention / Q000502:physiology*; D003463:Cues; D004594:Electrophysiology; D005403:Fixation, Ocular; D008251:Macaca; D009474:Neurons / Q000502:physiology*; D010775:Photic Stimulation; D014793:Visual Cortex / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*