Brain electric microstate and perception of simultaneously audiovisual presentation

Abstract

Associations between picture and sound form the basis of reading. Learning the correspondences between them is a crucial step in reading acquisition. This study was designed to investigate whether task-related processing of audio and visual features was independent or task-related processing in one modality might influence the processing of the other. The present study employed simultaneous audio-visual stimulus in the oddball paradigm to re-examine the effects of attention on audio, visual and audio-visual perception in the non-musician brain. Electroencephalographic (EEG) was recorded from 28 normal participants. None of them had more than three years of formal musical training and none had any musical training within the past five years. Chinese and Korean subjects were presented with tones (auditory: A), pictures (visual: V), and simultaneous tones and pictures (audio-visual: AV). The neural basis of this interaction was investigated by subtracting the event-related potentials (ERPs) to the A and the V stimuli alone from the ERP to the combined AV stimuli (i.e. interaction = AV - (A+V)). The Korean group showed larger mean interaction amplitude and longer in time than the Chinese group. This reveals that experience influences the early cortical automatic processing of linguistically relevant suprasegmental pitch contour. These results suggest that efficient processing of associations between pictures and sounds relies on neural mechanisms similar to those naturally evolved for integrating audiovisual perception. © 2009 Springer Berlin Heidelberg.