2. Basic studies of neural mechanism underlying rehabilitation
The neuroscientific effectiveness of showing lip shapes / articulation for rehabilitation
Showing pictured lip shapes or therapist's articulation is one of the methods for rehabilitation of patients with some types of aphasia. Previous studies reported that visual cues such as lip shapes help phonemic categories discrimination infants during language acquisition (Teinonen et al 2008) and second language learner (Navarra 2007). Thus, visual cues are important in rehabilitation. In fact, showing lip shapes / articulation is effective method to facilitate patients' speech production and used in daily clinical practice. However, there is no neuroscientific evidence of this method. Behavioral study (Schmid et al., 2006) reported impairment of audio-visual integration ability is shown in patients with aphasia, and this integration ability is related to word repetition ability that is audio-motor integration ability. Neuroimaging studies reported superior temporal sulcus (STS) involves in audio-visual integration (Hall et al., 2005, Matchin et al., 2014) and dorsal pathway of auditory processing involves in word repetition (Kuemmerer et al., 2013). These results suggested the possibility of interaction between STS and dorsal pathway of auditory processing. In this study, we aim to evaluate neuroscientific effectiveness of the lip shapes / articulation method and to clarify the neural network of multisensory integration (audio-visual and/or audio-motor) using electroencephalogram (EEG) and transcranial magnetic stimulation (TMS).