The eLORETA correlation analysis indicated that lagged phase synchronization in the theta band had a negative correlation with the MMSE scores: the higher the functional connectivity in the (slow) theta band across these regions the more the cognitive decline (lower MMSE scores). This included those cortical regions showing the highest between-group difference in theta lagged phase synchronization, namely the left temporal-right prefrontal (r = −0.31; p = 0.019, corrected) and left anterior temporal-right central (r = −0.29; p = 0.022, corrected) cortex. Significant correlations of theta connectivity with the MMSE scores were also observed between the left temporal-midcentral area and the right temporal-inferior parietal cortex (r = 0.28 corrected) (Fig. 6).
