Transcranial magnetic stimulation of the occipital cortex interferes with foot movements in blind individuals
Plasticity after visual loss is a remarkable characteristic of the brain. Previous studies in blind individuals have shown that the occipital cortex, which corresponds to the visual cortex in sighted individuals, can be reorganized and repurposed for nonvisual perception and cognitive functions. To our knowledge, however, no studies have directly examined its involvement in motor production. Here we show that a rhythmic foot movement performed by acquired blind participants can be disrupted by transcranial magnetic stimulation (TMS) to their primary and secondary visual cortex (V1/V2). Variability of this foot movement increased when we applied TMS to the acquired blind participants. This effect of TMS was absent for both sighted and congenitally blind participants. These results suggest that the visual cortex of blind individuals is involved in motor production, but its involvement requires prior visual experience. Our finding indicates that functional repurposing of the visual cortex may not be restricted to perception and cognitive functions, but also extended to motor function. Motor function may emerge in the visual cortex of blind individuals as a consequence of the reorganization of the visuomotor network, which has been developed before visual loss.