RT Journal Article
SR Electronic
T1 The visual cortex produces a signal in the gamma band in response to broadband visual flicker
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2021.01.11.426257
DO 10.1101/2021.01.11.426257
A1 Alexander Zhigalov
A1 Katharina Duecker
A1 Ole Jensen
YR 2021
UL http://biorxiv.org/content/early/2021/01/13/2021.01.11.426257.abstract
AB The aim of this study is to uncover the network dynamics of the human visual cortex by driving it with a broadband random visual flicker. We here applied a broadband flicker (1–720 Hz) while measuring the MEG and then estimated the temporal response function (TRF) between the visual input and the MEG response. This TRF revealed an early response in the 40–60 Hz gamma range as well as in the 8–12 Hz alpha band. While the gamma band response is novel, the latter has been termed the alpha band perceptual echo. The gamma echo preceded the alpha perceptual echo. The dominant frequency of the gamma echo was subject-specific thereby reflecting the individual dynamical properties of the early visual cortex. To understand the neuronal mechanisms generating the gamma echo, we implemented a pyramidal-interneuron gamma (PING) model that produces gamma oscillations in the presence of constant input currents. Applying a broadband input current mimicking the visual stimulation allowed us to estimate TRF between the input current and the population response (akin to the local field potentials). The TRF revealed a gamma echo that was similar to the one we observed in the MEG data. Our results suggest that the visual gamma echo can be explained by the dynamics of the PING model even in the absence of sustained gamma oscillations.Competing Interest StatementThe authors have declared no competing interest.