title: Gamma responses correlate with temporal expectation in monkey primary visual cortex.
abstract: Gamma oscillations have been linked to selective attention. Here, we investigate the effects of expecting a behaviorally relevant event (a change in the fixation point) on the oscillatory patterning of the local field potential and spiking responses in V1. Three protocols were used. In the first protocol, fixation point change occurred at a fixed time point, enabling predictions on task timing. In the second, fixation point change occurred in trial blocks either early or late in the trial, allowing us to compare responses during epochs of low and high expectation. Finally, we used a cue to indicate the upcoming fixation point change. All protocols led to an increase in gamma oscillations associated with alpha suppression when the monkeys expected an event in time. These effects were spatially widespread, since comparable results were observed for both central and peripheral visual representations in V1. Our findings indicate that expectations associated with perceptual decisions, motor responses, or upcoming reward may have a strong effect on the primary visual cortex, causing global, spatially nonselective modulation of gamma activity.
authors: Max Planck Institute for Brain Research, D-60528 Frankfurt am Main, Germany.
authors: Bruss
authors: B
authors: Lima
authors: Wolf
authors: W
authors: Singer
authors: Sergio
authors: S
authors: Neuenschwander
mesh_terms: D000200:Action Potentials / Q000502:physiology; D000818:Animals; D001288:Attention / Q000502:physiology*; D001931:Brain Mapping; D058256:Brain Waves / Q000502:physiology*; D003463:Cues; D004569:Electroencephalography; D005403:Fixation, Ocular; D008253:Macaca mulatta; D008297:Male; D009474:Neurons / Q000502:physiology; D009949:Orientation / Q000502:physiology; D010775:Photic Stimulation / Q000379:methods; D011930:Reaction Time / Q000502:physiology; D012201:Reward; D013057:Spectrum Analysis; D013223:Statistics as Topic; D013997:Time Factors; D014793:Visual Cortex / Q000166:cytology / Q000502:physiology*; D014794:Visual Fields / Q000502:physiology