title: Gamma Frequency and the Spatial Tuning of Primary Visual Cortex.
abstract: Visual stimulation produces oscillatory gamma responses in human primary visual cortex (V1) that also relate to visual perception. We have shown previously that peak gamma frequency positively correlates with central V1 cortical surface area. We hypothesized that people with larger V1 would have smaller receptive fields and that receptive field size, not V1 area, might explain this relationship. Here we set out to test this hypothesis directly by investigating the relationship between fMRI estimated population receptive field (pRF) size and gamma frequency in V1. We stimulated both the near-center and periphery of the visual field using both large and small stimuli in each location and replicated our previous finding of a positive correlation between V1 surface area and peak gamma frequency. Counter to our expectation, we found that between participants V1 size (and not PRF size) accounted for most of the variability in gamma frequency. Within-participants we found that gamma frequency increased, rather than decreased, with stimulus eccentricity directly contradicting our initial hypothesis.
authors.affiliation: Wellcome Trust Centre for Neuroimaging, UCL, London, WC1N 3BG, United Kingdom.|Institute of Cognitive Neuroscience, UCL, London, WC1N 3AR, United Kingdom.
authors.forename: Sarah
authors.identifier: http://orcid.org/0000-0003-4620-6963
authors.initials: S
authors.lastname: Gregory
authors.affiliation: Center for Mind/Brain Sciences, University of Trento, Mattarello, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Fusca
authors.affiliation: Wellcome Trust Centre for Neuroimaging, UCL, London, WC1N 3BG, United Kingdom.|Institute of Cognitive Neuroscience, UCL, London, WC1N 3AR, United Kingdom.
authors.forename: Geraint
authors.initials: G
authors.lastname: Rees
authors.affiliation: Institute of Cognitive Neuroscience, UCL, London, WC1N 3AR, United Kingdom.|Experimental Psychology, UCL, London, WC1H 0AP, United Kingdom.
authors.forename: D Samuel
authors.initials: DS
authors.lastname: Schwarzkopf
authors.affiliation: Wellcome Trust Centre for Neuroimaging, UCL, London, WC1N 3BG, United Kingdom.
authors.forename: Gareth
authors.initials: G
authors.lastname: Barnes
mesh_terms: D000328:Adult; D001931:Brain Mapping; D005260:Female; D065818:Gamma Rhythm / Q000502:physiology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D015225:Magnetoencephalography; D008297:Male; D009474:Neurons / Q000502:physiology; D010775:Photic Stimulation; D014793:Visual Cortex / Q000000981:diagnostic imaging / Q000502:physiology*; D014794:Visual Fields / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*; D055815:Young Adult