title: Prestimulus oscillatory phase at 7 Hz gates cortical information flow and visual perception.
abstract: Although we have the impression that visual information flows continuously from our sensory channels, recent studies indicate that this is likely not the case. Rather, we sample visual stimuli rhythmically, oscillating at 5-10 Hz. Electroencephalography (EEG) studies have demonstrated that this rhythmicity is reflected by the phase of ongoing brain oscillations in the same frequency. Theoretically, brain oscillations could underlie the rhythmic nature of perception by providing transient time windows for information exchange, but this question has not yet been systematically addressed. We recorded simultaneous EEG-fMRI while human participants performed a contour integration task and show that ongoing brain oscillations prior to stimulus onset predict functional connectivity between higher and lower level visual processing regions. Specifically, our results demonstrate that the phase of a 7 Hz oscillation prior to stimulus onset predicts perceptual performance and the bidirectional information flow between the left lateral occipital cortex and right intraparietal sulcus, as indicated by psychophysiological interaction and dynamic causal modeling. These findings suggest that human brain oscillations periodically gate visual perception at around 7 Hz by providing transient time windows for long-distance cortical information transfer. Such gating might be a general mechanism underlying the rhythmic nature of human perception.
authors.affiliation: Department of Psychology, University of Konstanz, 78457 Konstanz, Germany; Zukunftskolleg, University of Konstanz, 78457 Konstanz, Germany; School of Psychology, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK. Electronic address: s.hanslmayr@bham.ac.uk.
authors.forename: Simon
authors.initials: S
authors.lastname: Hanslmayr
authors.affiliation: Department of Experimental Psychology, University of Regensburg, 93053 Regensburg, Germany. Electronic address: gregor.volberg@psychologie.uni-r.de.
authors.forename: Gregor
authors.initials: G
authors.lastname: Volberg
authors.affiliation: School of Psychology, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK; MRC Cognition and Brain Sciences Unit, Cambridge CB2 7EF, UK.
authors.forename: Maria
authors.initials: M
authors.lastname: Wimber
authors.affiliation: Department of Psychology, University of Konstanz, 78457 Konstanz, Germany; Zukunftskolleg, University of Konstanz, 78457 Konstanz, Germany.
authors.forename: Sarang S
authors.initials: SS
authors.lastname: Dalal
authors.affiliation: Department of Experimental Psychology, University of Regensburg, 93053 Regensburg, Germany.
authors.forename: Mark W
authors.initials: MW
authors.lastname: Greenlee
mesh_terms: D000328:Adult; D004569:Electroencephalography; D005260:Female; D006801:Humans; D008297:Male; D033281:Nontherapeutic Human Experimentation; D009778:Occipital Lobe / Q000502:physiology*; D010296:Parietal Lobe / Q000502:physiology*; D010507:Periodicity; D010775:Photic Stimulation; D014793:Visual Cortex / Q000502:physiology; D014796:Visual Perception / Q000502:physiology*