Topography of functional connectivity in human multichannel EEG during second language processing

We analyze the topography of nonlinear interdependence in the EEG of two group German-native speakers, divided according to their English proficiency level (high or low), when listening to one text in German and one in English. Global functional connectivity was assessed in the full band EEGs using the nonlinear correlation integration entropy, an index of multivariate interdependence derived from the normalized cross-mutual information between every two electrodes within each region of interest (ROI): three interhemispheric (frontal, centro-temporal and parieto-occipital) and two intrahemispheric ones (left and right hemisphere). The results show clear topographic differences between the interhemispheric ROIs, but no differences between the intrahemispheric ROIs Furthermore, there were also differences in language processing that depend on the proficiency level. We discuss these results and their implications along with recent findings about phase synchronization in the gamma band during second language processing.