Objective:To examine and compare the synchronization of different brain regions during the Chinese and English Stroop tasks.Methods.Ten native Chinese speakers with a moderate command of English participated in this study,and event-related potentials were recorded while participants performed the Stroop task.Then wavelet-based estimation of instantaneous EEG coherence was applied to investigate the synchronization of different brain regions during Stroop task.Results:A greater negativity for the in- congruent situation than congruent situation appeared from 350ms to 600ms post-stimulus onset over frontal,central,and parietal regions in Chinese Stroop task,while the negativity was absent in English Stroop task.However,not only in Chinese Stroop task but also in English Stroop task was it found signif- icantly higher EEG coherences for the incongruent situation than congruent situation over frontal,pari- etal,and frontoparietal regions before 400ms post stimulus onset atβ(13-30 Hz) frequency band.Conclu- sion:This finding indicated that wavelet-based coherence is more exquisite tool to analyze brain electro- physiological signals associated with complex cognitive task than ERP component,and that functional syn- chronization indexed by EEG coherence is enhanced at the earlier stage while processing the conflicting in- formation for the incongruent stimulus.
