Brain Connectivity

Brain networks and meditation have recently gained attention, with studies suggesting that more efficiently organized meditation brain networks are linked to better cognitive performance. This efficiency is exemplified in small-world brain networks, which combine local segregation with global integration, facilitating optimal information processing. This study examines the small-world propensity (SWP), a marker of neural efficiency, among three functional brain networks: the default mode network (DMN), fronto-parietal network (FPN), and attention network (AN) in three groups: advanced meditators (AM), beginner meditators (BM), and control meditators (CM).

Using magnetoencephalography (MEG), we recorded 10-min meditation sessions from AM and BM groups practicing Surat-Shabda-Yoga meditation at different stages. The CM (baseline group), with no formal training in meditation, had introductory exposure to “four chakra meditation” and practiced the same. SWP was computed using coherence-based connectivity measures across frequencies ranging from 4 to 45 Hz during stable meditative states.

Significant differences were observed between meditators and non-meditators, with AM and BM groups compared with the CM group. Specifically, the AN in the AM group compared with CM exhibited higher SWP at the beta frequency range (19 Hz), while the FPN in the BM group compared with the CM showed increased SWP at the theta frequency range (8 Hz).

These findings highlight how meditation engages the brain’s intrinsic network architecture in a frequency- and stage-specific manner, supporting efficient information processing and offering a scientific basis for its cognitive and regulatory benefits.

This study reveals how meditation naturally resonates with the brain’s intrinsic architecture, promoting efficient network organization through small-world topology. Using MEG and coherence-based connectivity, we demonstrate frequency-specific adaptations in key functional networks such as DMN, FPN, and -AN across meditation stages. These changes highlight how meditation leverages neural connectivity for optimized information processing by linking contemplative practice to intellectual benefits. It contributes to the field of brain connectivity by positioning meditation as a modulator of functional network dynamics with potential cognitive applications.

Tinnitus is an auditory phantom perception in the absence of any corresponding acoustic stimulus whose pathophysiology remains poorly understood. This study aimed to investigate alterations in the functional organization of the brain in individuals with tinnitus using resting-state functional magnetic resonance imaging (rs-fMRI) and graph theory analysis.

We conducted a study including 44 individuals with tinnitus and 32 healthy controls. Using rs-fMRI and graph theory measures, we characterized whole-brain topological properties, including network segregation, integration, small-worldness, and global efficiency. In addition, regional segregation and integration were assessed using clustering coefficient and participation coefficient analyses to identify alterations in brain hub regions.

Our findings revealed altered topological properties in the tinnitus brain, particularly in the balance between cerebral segregation and integration, leading to deviations from optimal small-world architecture. We also observed alterations in the topology of specific auditory and nonauditory brain regions associated with phantom sound perception. Notably, patients with tinnitus exhibited a decreased nodal participation coefficient in the thalamus, suggesting reduced connectivity between this region and different functional modules as well as long-range connections.

These results suggest that tinnitus is associated with alterations in the functional organization of the brain, leading to disrupted information processing and sensory integration.

This article investigates functional modifications in patients with chronic tinnitus using resting-state functional magnetic resonance imaging and graph theory analysis. The results show that individuals with tinnitus, compared with healthy volunteers, exhibit distinct topological patterns in their resting-state brain activity. We demonstrate decreased segregation in several brain regions in patients with tinnitus, as well as decreased integration in the right thalamus. These results suggest that tinnitus may be associated with alterations in the functional organization of the brain, leading to disrupted information processing and sensory integration.

Investigation of the neural substrates of post-traumatic stress disorder (PTSD) in military personnel using whole-brain approaches remains scarce, hindering the development of circuit-based neuromodulatory interventions.

This study aimed to identify potential associations between clinical symptoms and whole-brain resting-state functional connectivity with magnetic resonance imaging in military personnel with adulthood-onset war-related PTSD.

Thirty-seven soldiers from the Canadian Armed Forces with moderate to severe treatment-resistant PTSD participated in this study. We assessed PTSD, anxiety and depressive symptoms, quality of life, and time since trauma. We characterized the whole-brain functional connectome using independent component analysis and regions of interest (ROI)-to-ROI connectivity, as well as its topology using graph theory.

Greater severity of PTSD and anxiety symptoms was associated with lower connectivity (r < 0) between the default mode network (DMN) and frontoparietal network. Greater severity of PTSD symptoms was also associated with a higher nodal clustering coefficient of the inferior parietal lobule from the DMN. Greater severity of anxiety symptoms and longer time since trauma was the only clinical variables that correlated with higher connectivity patterns, all involving the visual networks (the frontoparietal-visual, the visual-DMN, and within-visual networks).

This work contributes to identifying brain targets for the development of personalized neuromodulatory interventions. In particular, the DMN may be a promising target to alleviate PTSD symptoms, and the visual network may be a target to treat comorbid anxiety symptoms.

This work aimed to identify clinical correlates of resting-state functional connectivity in military personnel with post-traumatic stress disorder (PTSD) refractory to psychotherapy and pharmacotherapy (N = 37). Our findings indicate that increasing connectivity between the default mode and frontoparietal networks may be a promising therapeutic target to alleviate PTSD symptoms with personalized neuromodulatory interventions, whereas reducing connectivity within the visual network may constitute a target to treat comorbid anxiety. They also emphasize the importance of investigating clinical correlates using whole-brain methods to uncover new target engagement for therapeutic brain circuitry candidates.

Novel therapies are needed to improve smoking cessation outcomes in people with opioid use disorder (OUD), as they are far more likely to smoke cigarettes (70–90%) compared to the general population (11.6%) and demonstrate a poorer response to smoking cessation interventions.

This pilot study, intended to be a hypothesis-generating mechanistic investigation, is the first to explore the impact of a single day (four sessions) of accelerated intermittent theta burst stimulation (iTBS) (1800 pulses/session) versus sham iTBS applied to the left dorsolateral prefrontal cortex (L-dlPFC) in people with OUD who smoke tobacco cigarettes (n = 8 received iTBS, n = 7 received sham iTBS). Resting-state functional connectivity was acquired at baseline and after the fourth session. Attentional bias for cigarette and opioid cues, and craving assessments, were completed at baseline, and after the first and fourth sessions.

Connectivity between the L-dlPFC seed and a cluster comprising the left anterior supramarginal gyrus showed a significant group × time interaction, with planned comparisons showing a greater increase at follow-up in the iTBS compared with sham iTBS group (t₁₂ = 6.37, β = 0.40, p < 0.001). Cigarette cue attentional bias showed a significant group × session interaction (t₈₀ = 2.34, p = 0.02), with planned comparisons showing a decrease after iTBS and an increase following sham iTBS. No effect of iTBS was observed for opioid cue attentional bias. Cigarette craving decreased in both iTBS and sham groups but did not show a significant group × session interaction.

These results are promising but should be interpreted with caution, given the limited sample size, which precluded analyses adjusting for sex or medications for OUD. This pilot study aims to identify neural and behavioral targets for future studies of accelerated iTBS in people with OUD who smoke cigarettes. Future trials could examine the effects of increased doses of iTBS (e.g., more days of accelerated iTBS) to identify dosing to promote smoking cessation among individuals with OUD effectively.

Accelerated intermittent theta burst stimulation has been paradigm-shifting in the treatment of major depressive disorder. Similarly, it could provide a robust and efficient adjunct smoking cessation intervention for people with OUD who smoke cigarettes.