Repetitive transcranial magnetic stimulation alters optic flow perception.

Optic flow, the visual motion radiating from the center to side or opposite directions, is used to control human locomotion. Low-frequency repetitive transcranial magnetic stimulation (0.9 Hz, 10 min) was applied to the primary visual cortex (V1) and the extrastriate area (V5/MT) of 12 healthy participants to study effects of repetitive transcranial magnetic stimulation on coherent optic flow perception. Cz stimulation was used as control. Participants were instructed to correctly identify focus for dots with coherent optic flow motion. Ratios of reaction times between V1 and Cz or between V5 and Cz 40 min after repetitive transcranial magnetic stimulation significantly increased. These results suggest the prolonged inhibitory effect of low-frequency repetitive transcranial magnetic stimulation on optic flow perception. Low-frequency repetitive transcranial magnetic stimulation is a useful tool for exploring visuospatial cognition.