Brain Electrical Source Analysis during Tonal and Phonetic Oddball Paradigms
1 College of Mechatronics and Control Engineering, Shenzhen University, Shenzhen 518060, China
2 (Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
3 The First Affiliated Hospital of Shenzhen University, Shenzhen 518035, China
4 Institute of Biomedical Engineering，Chinese Academy of Medical Sciences，Tianjin 300192, China
Abstract：In this paper, time courses of discrete cortical current sources evoked by target stimuli were investigated with tonal and phonetic oddball paradigms. 64-channel ERPs were recorded in healthy subjects during the paradigms. A regional source model was then introduced to ERPs data in response to tonal and phonetic target stimuli. Activities of regional sources indicated bilateral superior temporal gyri and bilateral insula were sources involved in auditory target detection. While tonal and phonetic task were compared, tonal target detection produced right-greater-than-left hemispheric asymmetry of N2/P3 amplitude in bilateral source activities and the asymmetry more obviously occurred in bilateral insula, and on the contrary, phonetic target detection produced left-greater-than-right hemispheric asymmetry of N2/P3 amplitude in bilateral source activities and the asymmetry obviously occurred in bilateral superior temporal gyri and insula. It was indicated that target processing was modality-specific, tonal target detection produced stronger activation of right insula and right superior temporal gyrus, while phonetic target processing involved stronger activations of left superior temporal gyrus.
