Brain Connectivity
December 5, 2016
Lauren Mak, Luciano Minuzzi, Glenda Macqueen et al.
354 citations
The default mode network (DMN) is a set of brain regions active during rest and self-referential thought. This review of studies up to August 2016 examined how DMN functional connectivity varies in healthy people by age, sex, cognitive function, and analysis method. DMN connectivity follows an inverse U-shape across the lifespan: strongest in adulthood, lowest in children and the elderly. Cognitive function positively correlates with DMN connectivity. Females show stronger intranetwork connectivity than males. Effects of analysis type were inconclusive. A voxel-wise meta-analysis for age confirmed an immature network in children versus adults and a stronger network in adults versus the elderly. Defining normal variation may help identify DMN changes in pathology.
Brain Connectivity
October 1, 2011
Vesa Kiviniemi, Tapani Vire, Jukka Remes et al.
268 citations
The spatial layout of the brain's default mode network (DMN) fluctuates over time, even when a person is at rest. Using a sliding time window analysis of functional connectivity MRI data from 12 participants, the authors found that the spatial similarity of successive DMN maps varied at low frequencies and followed a 1/f power spectral pattern. A single voxel appeared within a group DMN map in at most 82% of time windows, indicating marked temporal variation. Incidental connectivity increased centrifugally toward brain areas outside the DMN core. The method, SliTICA, captures this spatial variance and may provide a more complete measure of a network's functional activity.
Brain Connectivity
June 1, 2026
Geeta Prem Chandoo Damisetti, C M Markan, Sona Ahuja et al.
Meditation alters brain network organization in a frequency- and experience-dependent way. Using magnetoencephalography, researchers measured small-world propensity (SWP), a marker of neural efficiency, in three functional networks—default mode, fronto-parietal, and attention—among advanced meditators, beginner meditators, and a control group with no formal training. Advanced meditators showed higher SWP in the attention network at 19 Hz (beta frequency) compared to controls, while beginners showed higher SWP in the fronto-parietal network at 8 Hz (theta frequency). These results suggest that Surat-Shabda-Yoga meditation engages brain networks in a stage-specific manner, supporting efficient information processing.
Brain Connectivity
March 1, 2021
Lucie Bréchet, David A Ziegler, Alexander J. Simon et al.
After six weeks of breath-focused, digital meditation training, young adults showed changes in resting-state brain networks measured by EEG microstates, particularly in the right insula, superior temporal gyrus, superior parietal lobule, and superior frontal gyrus bilaterally. These topographical changes were not seen in an active placebo control group. The results suggest that this low-cost, digital meditation practice can reorganize brain network connectivity and may offer a novel, noninvasive approach for treating neuropathological conditions.
Brain Connectivity
February 1, 2021
Danish M. Khan, Nidal Kamel, Mustapha Muzaimi et al.
Electroencephalography (EEG), with its high temporal resolution, was used to estimate effective connectivity within the default mode network (DMN) in 20 subjects with alcoholism and 25 healthy controls. The resulting connectivity diagrams revealed unidirectional causal effects among DMN regions. Variations in these causal effects between controls and alcoholics correlated with symptoms commonly associated with alcoholism, such as cognitive and memory impairments, executive control deficits, and attention deficiency. The findings provide insight into how alcohol modulates cognitive and executive functions, potentially aiding treatment for alcohol use disorder.
Brain Connectivity
April 1, 2017
Donald E Lee, Lauren G Lee, Danny Siu et al.
During asphyxial cardiac arrest in rats, the brain's electrical activity passes through four distinct stages before electrocerebral silence. A transient period of near-electrocerebral silence lasting several seconds is linked to a significant increase in frontal coherence between left and right motor cortices, with no corresponding increase in power. This stage also shows a significant posterior shift of electrographic power toward the visual cortices. These distinctive neural features—a burst in frontal coherence and posterior power shift—may be neural correlates of conscious processing in the dying brain.
Brain Connectivity
February 1, 2016
Tun Jao, Chia-Wei Li, Petra E Vértes et al.
Meditation produces a distinct, reversible mental state that reorganizes brain network hubs and connections without altering global network properties like small-worldness. Analyzing resting-state fMRI data from 18 Taoist meditators of varying expertise, the study found that during meditation, sensory cortex areas (primary visual and auditory cortices, temporopolar areas) showed decreased connectivity, while the thalamus and default mode network components (precuneus, posterior cingulate cortex) increased connectivity. Long-distance front-to-back connections increased, while right-left connections between homologous cortices decreased. These changes suggest that shifts in consciousness involve both topological and spatial reorganization of brain networks, with the anatomical pattern of integration being as important as its overall level.