Investigating visual motion perception using the transcranial magnetic stimulation-adaptation paradigm.

The state-dependency approach of transcranial magnetic stimulation (TMS) enables differential stimulation of functionally distinct neural populations within the affected region of cortex. Here we tested the validity of a paradigm based on state-dependency, the TMS-adaptation paradigm, in the context of visual motion perception. Visual adaptation was used to induce an activity imbalance in direction-selective neurons in the visual cortex, after which participants performed a motion direction discrimination task. When TMS was applied over the motion-selective area V5/MT before each experimental trial, the detection of the direction encoded by the adapted neurons was facilitated relative to the direction encoded by the nonadapted neurons. This finding demonstrates, in the domain of visual motion detection, the state-dependency of TMS effects and the validity of the TMS-adaptation paradigm.