Stimulus-induced gamma power predicts the amplitude of the subsequent visual evoked response

• Published in: NeuroImage (Orlando, Fla.) Vol. 186; pp. 703 - 712
• Main Authors: van Es, Mats W.J., Schoffelen, Jan-Mathijs
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.02.2019; Elsevier Limited
• Subjects: Age; Behavior; Evoked activity; Experiments; Gamma; Magnetoencephalography; MEG; Oscillation; Rhythm; Studies; Synchronization; Visual cortex; Visual evoked potentials; Visual stimuli; Visual system; Evoked activity; Gamma; Visual cortex; Synchronization; MEG; Oscillation
• ISSN: 1053-8119; 1095-9572
• DOI: 10.1016/j.neuroimage.2018.11.029

The efficiency of neuronal information transfer in activated brain networks may affect behavioral performance. Gamma-band synchronization has been proposed to be a mechanism that facilitates neuronal processing of behaviorally relevant stimuli. In line with this, it has been shown that strong gamma-band activity in visual cortical areas leads to faster responses to a visual go cue. We investigated whether there are directly observable consequences of trial-by-trial fluctuations in non-invasively observed gamma-band activity on the neuronal response. Specifically, we hypothesized that the amplitude of the visual evoked response to a go cue can be predicted by gamma power in the visual system, in the window preceding the evoked response. Thirty-three human subjects (22 female) performed a visual speeded response task while their magnetoencephalogram (MEG) was recorded. The participants had to respond to a pattern reversal of a concentric moving grating. We estimated single trial stimulus-induced visual cortical gamma power, and correlated this with the estimated single trial amplitude of the most prominent event-related field (ERF) peak within the first 100 ms after the pattern reversal. In parieto-occipital cortical areas, the amplitude of the ERF correlated positively with gamma power, and correlated negatively with reaction times. No effects were observed for the alpha and beta frequency bands, despite clear stimulus onset induced modulation at those frequencies. These results support a mechanistic model, in which gamma-band synchronization enhances the neuronal gain to relevant visual input, thus leading to more efficient downstream processing and to faster responses. •Higher induced gamma power before a go cue leads to faster behavioral responses.•Gamma power positively correlates with the amplitude of early evoked activity.•Higher amplitudes of early evoked activity also lead to faster behavioral responses.•These results are specific to the gamma band.