Spontaneous modulations of high frequency cortical activity

ABSTRACTObjectiveWe clarified the clinical and mechanistic significance of physiological modulations of high-frequency broadband cortical activity associated with spontaneous saccadic eye movements during a resting state.MethodsWe studied 30 patients who underwent epilepsy surgery following extraoperative electrocorticography and electrooculography recordings. We determined whether high-gamma activity at 70-110 Hzpreceding saccade onsetwould predict upcoming ocular behaviors. We assessed how accurately the model incorporating saccade-related high-gamma modulations would localize the primary visual cortex defined by electrical stimulation.ResultsThe whole-brain level dynamic atlas demonstrated transient high-gamma suppression in the striatal region before saccade onset and high-gamma augmentation subsequently involving the widespread posterior brain regions. More intense striatal high-gamma suppression predicted the upcoming saccade directed to the ipsilateral side and lasting longer in duration. The bagged-tree-ensemble model demonstrated that intense saccade-related high-gamma modulations localized the visual cortex with an accuracy of 95%.ConclusionsWe successfully animated the neural dynamics supporting saccadic suppression, a principal mechanism minimizing the perception of blurred vision during rapid eye movements. The primary visual cortexper semay prepareactively in advancefor massive image motion expected during upcoming prolonged saccades.SignificanceMeasuring saccade-related electrocorticographic signals may help localize the visual cortex and avoid misperceiving physiological high-frequency activity as epileptogenic.Highlights-The whole-brain level dynamic atlas animated spontaneous high gamma modulations associated with saccadic eye movements.-Preceding high gamma activity in the striatal cortex predicted the direction and duration of the upcoming saccades.-Saccade-related high-gamma modulations localized the stimulation-defined visual cortex with an accuracy of 95%.