Author: Reiko MatsushitaPublisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
"Hemispheric asymmetries in processing of different acoustic features are well-known aspect of the auditory cortex. According to one model; the auditory cortex in the left hemisphere is tuned to process rapidly changing temporal information, which are abundant in human speech, and the auditory cortex in the right hemisphere play a dominant role in spectral processing hence significantly contributing to pitch processing. In the past, this spectral-temporal model of the auditory cortex has been addressed mainly using neuroimaging techniques, which inform us about correlational relationships between behaviors and brain activities. In the present thesis, we seek causal evidence that supports the spectral-temporal model, focusing on the right-hemisphere dominance in pitch processing, using transcranial direct current stimulation (tDCS).tDCS is a relatively new technique, which has potential to allow us to address the causal role of certain brain activities, to explore functional connectivity, and possibly to help different neurological and psychological conditions. However, little is known about the mechanisms of tDCS, especially in the auditory domain. We aimed to elucidate the mechanisms of tDCS in the human auditory system, and to develop a protocol to assess the right-hemisphere dominance in pitch processing and learning using tDCS.In the first study (chapter 2), we established a behavioural paradigm to test tDCS-induced effect on pitch processing using a pitch discrimination test called micromelody discrimination task. In this task short tone patterns using small (