Cortical oscillations related to processing congruent and incongruent grapheme-phoneme pairs
In this study, we investigated changes in cortical oscillations following congruent and incongruent grapheme-phoneme stimuli. Hiragana graphemes and phonemes were simultaneously presented as congruent or incongruent audiovisual stimuli to native Japanese-speaking participants. The discriminative reaction time was 57ms shorter for congruent than incongruent stimuli. Analysis of MEG responses using synthetic aperture magnetometry (SAM) revealed that congruent stimuli evoked larger 2-10 Hz activity in the left auditory cortex within the first 250 ms after stimulus onset, and smaller 2-16 Hz activity in bilateral visual cortices between 250 and 500 ms. These results indicate that congruent visual input can modify cortical activity in the left auditory cortex.
Herdman A.T., Fujioka T., Chau W., Ross B., Pantev C. & Picton T.W.
Author Keywords: cortical oscillations; magnetoencephalography; beamformer; audiovisual; grapheme; phoneme KeyWords Plus: HUMAN BRAIN; MULTISENSORY CONVERGENCE; DESYNCHRONIZATION; INTEGRATION; SYNCHRONIZATION; CORTEX; SPEECH; TASK Publisher: ELSEVIER IRELAND LTD, ELSEVIER HOUSE, BROOKVALE PLAZA, EAST PARK SHANNON, CO, CLARE, 00000, IRELAND Subject Category: Neurosciences IDS Number: 042KL ISSN: 0304-3940 DOI: 10.1016/j.neulet.2006.01.069