Functionally Distinct Gamma Range Activity Revealed by Stimulus Tuning in Human Visual Cortex.

ABSTRACT: Neocortical gamma activity has long been hypothesized as a mechanism for synchronizing brain regions to support visual perception and cognition more broadly. Although early studies focused on narrowband gamma oscillations (∼20-60 Hz), recent work has emphasized a more broadband "high-gamma" response (∼70-150+ Hz). These responses are often conceptually or analytically treated as synonymous markers of gamma activity. Using high-density intracranial recordings from the human visual cortex, we challenge this view by showing distinct spectral, temporal, and functional properties of narrow and broadband gamma. Across four experiments, narrowband gamma was strongly selective for gratings and long-wavelength colors, displaying a delayed response onset, sustained temporal profile, and contrast-dep

SUBMITTER: Bartoli E 

PROVIDER: S-EPMC6810857 | biostudies-literature | 2019 Oct

REPOSITORIES: biostudies-literature