Enhanced brain activity preceding voluntary movement in early blind humans.

Effects of blindness on movement-related brain activity were investigated by measuring from the scalp movement-related potentials (MRPs) associated with self-paced button presses in blind and sighted young adults. The blind subjects had lost their vision at an early age due to a deficit in the peripheral visual system. The negative slope (NS') of MRP at about 400 ms prior to movement and the preceding readiness potential (RP) were larger in the blind than in the sighted subjects, but were similarly distributed on the scalp in these groups. The results suggest functional changes in the blind subjects' brain activity, presumably, in the cortical areas involved in preparation and initiation of voluntary movement.