Temporal Dynamics of the Default Mode Network Characterize Meditation-Induced Alterations in Consciousness

Abstract

Current research suggests that human consciousness is associated with complex, synchronous interactions between multiple cortical networks. In particular, the default mode network (DMN) of the resting brain is thought to be altered by changes in consciousness, including the meditative state. However, it remains unclear how meditation alters the fast and ever-changing dynamics of brain activity within this network. Here we addressed this question using simultaneous electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) to compare the spatial extents and temporal dynamics of the DMN during rest and meditation. Using fMRI, we identified key reductions in the posterior cingulate hub of the DMN, along with increases in right frontal and left temporal areas, in experienced meditators during rest and during meditation, in comparison to healthy controls (HCs). We employed the simultaneously recorded EEG data to identify the topographical microstate corresponding to activation of the DMN. Analysis of the temporal dynamics of this microstate revealed that the average duration and frequency of occurrence of DMN microstate was higher in meditators compared to HCs. Both these temporal parameters increased during meditation, reflecting the state effect of meditation. In particular, we found that the alteration in the duration of the DMN microstate when meditators entered the meditative state correlated negatively with their years of meditation experience. This reflected a trait effect of meditation, highlighting its role in producing durable changes in temporal dynamics of the DMN. Taken together, these findings shed new light on short and long-term consequences of meditation practice on this key brain network.

Capturing the spatiotemporal dynamics of task-initiated thoughts with combined EEG and fMRI

“…Decrease of microstate C duration has also been described when subjects are engaged in object or verbal visualization tasks compared to rest (56). Based on these and other studies, it is assumed that microstate C reflects activity in the DMN (38,(55)(56)(57); for a discussion, see (17). Indeed, our analysis of the sources underlying this microstate confirms such interpretation.…”

Emerging Phenomenological and Biological Principles of Consciousness: Top Insights of Prevailing Models, Concepts, and Observations

“…The majority of brain energy consumption is attributed to this intrinsic activity [154]. The DMN being a key component of such an essential layer underlying consciousness is supported by research correlating DMN connectivity to level of consciousness in brain-damaged patients [53], behavioral signs of awareness [155], and some meditative experiences [156]. We assert that intrinsic brain activity uses so much energy due to its function in maintaining the neural framework that founds the subconscious 3D virtual matrix necessary for conscious perceptions [12].…”

Dynamic Configuration of Coactive Micropatterns in the Default Mode Network during Wakefulness and Sleep

“…These findings illustrate that DMN activity is functionally reorganized during sleep and might further reflect levels of consciousness. Additionally, fast and ever-changing dynamics of DMN activity have also been observed in various consciousness levels, and the temporal aspects of spontaneous DMN activity might be associated with conscious processes (Kapogiannis et al, 2014;Panda et al, 2016). Therefore, the close association between DMN activity and consciousness represents an important topic to study for an understanding of the physiological mechanism of consciousness by revealing the dynamic configuration of fast DMN activity, which has not been completely elucidated.…”