VIBROTACTILE AID AND BRAIN CORTICAL ACTIVITY

Six profoundly deaf patients were studied with mapping evoked potentia ls (MEP) using an acoustic signal passed through the vibrotactile pros thesis. This stimulus produced an activation of the central sulcus bra in cortex. When the prothesis was placed in the presternal area it sho wed N1 P1 potentials with higher voltage and a more defined cortical d ipole inversion than when the prosthesis was placed in the arm or abdo men: thus the presternal stimulation is considered an adequate place f or the use of vibrotactile stimulation. The MEP were recorded in 2 pat ients after a period of audiological training and they showed new earl ier potentials. These suggest plastic changes in the processing of an acoustic signal sent from the presternal skin by the somatosensory pat hway after training and involving learning procedures.