Dynamical properties of BOLD activity from the ventral posteromedial cortex associated with meditation and attentional skills.

Brain imaging data show that experienced Zen meditators, compared to non-meditators, exhibit less frequent high-activity states in the ventral posteromedial cortex (vPMC), a hub of the default mode network linked to spontaneous thought. During a simple attention-to-breathing task, the skewness of the fMRI signal in the vPMC differed significantly between groups, and this measure correlated with performance on a sustained-attention test outside the scanner. Functional connectivity between the vPMC and the right temporoparietal junction, a region involved in redirecting attention, also related to test performance. These patterns may reflect the interplay of mind-wandering, meta-awareness, and focused attention, offering a potential marker for attentional abilities and their disruption in clinical conditions.

Study at a glance

Abstract

Neuroimaging data suggest a link between the spontaneous production of thoughts during wakeful rest and slow fluctuations of activity in the default mode network (DMN), a set of brain regions with high basal metabolism and a major neural hub in the ventral posteromedial cortex (vPMC). Meta-awareness and regulation of mind-wandering are core cognitive components of most contemplative practices and to study their impact on DMN activity, we collected functional MRI (fMRI) data from a cohort of experienced Zen meditators and meditation-naive controls engaging in a basic attention-to-breathing protocol. We observed a significant group difference in the skewness of the fMRI BOLD signal from the vPMC, suggesting that the relative incidence of states of elevated vPMC activity was lower in meditators; furthermore, the same parameter was significantly correlated with performance on a rapid visual information processing (RVIP) test for sustained attention conducted outside the scanner. Finally, a functional connectivity analysis with the vPMC seed revealed a significant association of RVIP performance with the degree of temporal correlation between vPMC and the right temporoparietal junction (TPJ), a region strongly implicated in stimulus-triggered reorienting of attention. Together, these findings suggest that the vPMC BOLD signal skewness and the temporal relationship of vPMC and TPJ activities reflect the dynamic tension between mind-wandering, meta-awareness, and directed attention, and may represent a useful endophenotype for studying individual differences in attentional abilities and the impairment of the latter in specific clinical conditions.