This study will examine the spatiotemporal dynamics of sensory tics in patients with Tourette syndrome (TS). We will also investigate the possible existence of a sensory gating problem. By investigating somatosensory evoked responses from stimulation of the trigeminal nerve (tSERs) on affected versus unaffected sides of the face, we hope to identify differences in the SER waveforms that suggest sensory abnormalities. We will use a series of short trains of stimulations on the affected side to examine habituation, subsequently performing a time-