Figure 1. Representative simultaneous recordings of electromyographic activities of orofacial muscles and tongue pressure during visual feedback training of tongue movements. Electromyographic activities were recorded from bilateral anterior and posterior temporalis, masseter, and digastric muscles, and tongue pressure was recorded bilaterally by a pressure transducer. The subject performed tongue movement (i.e., lateral excursion of the tongue tip to touch the ipsilateral pressure transducer) between the two arrows. Note that while bilateral activation of several orofacial muscles was seen with tongue moments during clenching and swallowing, lateral tongue movements could be performed (between arrows) with a minimum activation of orofacial muscles and without touching the contralateral pressure transducer. The horizontal bar denotes 1.0 sec. Vertical bars denote 50 mV for T_R and T_L, 200 mV for clenching and swallowing in EMG records, and 20 g/cm² for tongue pressure. Abbreviations: T_R, tongue movement to the right; T_L, tongue movement to the left.