Interference in tactile discrmination performance by neuronal modulation

Abstract

Perceiving and processing sensory stimuli are essential to generate motor action. Previous studies suggested features of vibrotactile stimulus such as amplitude and frequency are differently represented onto somatosensory cortices so that the stimulus can be discriminated. In the present study, we aimed to demonstrate the effect of transcranial magnetic stimulation (TMS) triplet pulses over primary somatosensory cortex (S1) or secondary somatosensory cortex (S2) on a tactile discrimination task. In two alternative forced choice task, TMS over Si or S2 significantly interfered with the discrimination performance. This disruptive influence was mostly shown when the vibrotactile stimulus was close to high frequency (320Hz). Therefore we concluded the inhibitory effect of TMS is selective with tactile frequency.