Cortico-cortical evoked potentials and stimulation-elicited gamma activity preferentially propagate from lower- to higher-order visual areas

Highlights ► Electrical stimulation of the lower-order visual cortex elicited cortico-cortical evoked potentials (CCEPs) and augmentation of gamma activity in the higher-order visual cortex via feed-forward propagations. ► Electrical stimulation of the higher-order visual cortex elicited smaller CCEPs but no detectable gamma-augmentation in the lower-order visual cortex via feed-back propagations. ► Difference in the propagation manners of stimulation-elicited cortical-signals between feed-forward and feed-back directions may need to be taken into consideration for future clinical application of CCEPs and stimulation-elicited gamma-augmentation in presurgical evaluation for epilepsy surgery.