Differences in Default Mode Network Connectivity in Meditators and Non-meditators During an Attention Task

Abstract

Activity in the default mode network (DMN) is reduced during non-self-referential goal-directed tasks in healthy individuals. In this study, we investigated differences in DMN functional connectivity between regular meditators and non-meditators during an attention paradigm. Non-meditators and regular meditators, matched by age, years of education, and gender were instructed to name the color of single words visually presented in a Stroop Word-Color Task (SWCT) adapted for functional magnetic resonance imaging (fMRI). The task was performed when the participants were not formally meditating. Logistic analysis based on imaging data indicated that the connectivity between the PCC (precuneus/posterior cingulate cortex) and the right and left parietal lobules helps differentiating regular meditators from non-meditators. Granger causality results showed that the activity in the PCC contains information to predict the activity in the right lateral parietal cortex and that the accuracy in this prediction is higher in regular meditators when compared to non-meditators. This suggests a stronger link between these two regions in regular meditators. In contrast to regular meditators, the PCC is more influenced by the left parietal region (related to the process of reading—which is the interference in the SWCT), and this region is more influenced by the PCC in non-meditators. These functional connectivity differences in the DMN between groups possibly reflect a higher degree of interference and probably more distraction during the SWCT in non-meditators compared with meditators.