Poster F2, Tuesday, March 28, 8:00 – 10:00 am, Pacific Concourse
Spatial attention reduces visual cortical 1/f neural noise
Tam Tran1, Adam Gazzaley2, Bradley Voytek1; 1University of California, San Diego, 2University of California, San Francisco
Noise modulation, for instance the reduction of response variability, is a proposed mechanism by which selective attention improves perceptual processing. While this noise mechanism has been extensively examined in animal studies, methodological constraints have limited its applicability in human studies. In this EEG experiment, we leverage the recent finding that the slope of the 1/f electrophysiological power spectrum may index neural noise. Participants performed a perceptual discrimination task in which they were required to focus or divide their attention across narrow or broad areas of visual space. Using 1/f slope to index neural noise, we found that narrowly focused attention decreased pre-target noise in visual areas contralateral, but not ipsilateral to attended spatial locations. Importantly, pre-target noise was lowest in the most focused attention conditions, increasing monotonically with more divided attentional distribution. These findings suggest new possibilities by which the direct study of noise modulation, previously conducted only invasively, can extend to include human cognitive studies.
Topic Area: ATTENTION: Spatial