Brain Research Bulletin
October 15, 2023
Saampras Ganesan, Bradford A. Moffat, Nicholas T. van Dam et al.
13 citations
Using 7 Tesla functional MRI, a pilot study scanned 10 beginner meditators during focused attention meditation (attending to breathing) and non-focused rest. After adjusting for physiological differences, meditation reduced activity in default-mode network hubs (antero-medial prefrontal and posterior cingulate cortices, precuneus) and visual and thalamic regions compared to rest. These reductions survived stringent corrections for physiological fluctuations. State mindfulness scores rose significantly after the session and remained elevated at a 2-week follow-up. The findings support evidence that focused attention meditation dampens default-mode activity tied to self-referential processing and demonstrate the feasibility of ultra-high field fMRI for meditation research.
Mindfulness (N Y)
September 26, 2025
Saampras Ganesan, Nicholas T. van Dam, Sunjeev K. Kamboj et al.
3 citations
A 7-Tesla MRI study found that neurofeedback training (NFT) helps people become more aware of their mental states and boosts emotional well-being during real-world meditation. Participants who received NFT showed improved self-awareness and greater emotional benefits from meditation compared to those who did not receive NFT. The results suggest that NFT can enhance the positive effects of meditation practice.
bioRxiv (Cold Spring Harbor Laboratory)
October 26, 2024
Saampras Ganesan, Nicholas T. van Dam, Sunjeev K. Kamboj et al.
3 citations
preprint
Personalized high-precision neurofeedback (NF) can help novice meditators better disengage from mental activity during meditation, improving emotional well-being and mindful awareness. In a single-blind, controlled study, 40 novices received two days of meditation training with feedback from either their own or a matched participant's posterior cingulate cortex (PCC) activity, measured using 7 Tesla fMRI. The experimental group showed stronger functional decoupling of PCC from dorsolateral prefrontal cortex, indicating improved control over disengagement. This led to greater improvements in emotional well-being and mindful awareness during a week of real-world self-guided meditation, supporting the utility of NF-guided meditation training.
bioRxiv (Cold Spring Harbor Laboratory)
January 3, 2023
Saampras Ganesan, Bradford A. Moffat, Nicholas T. van Dam et al.
1 citation
preprint
Using ultra-high strength 7 Tesla fMRI, a pilot study scanned 10 beginner meditators during focused attention meditation and rest. Meditation significantly reduced activity in Default-mode network hubs—antero-medial prefrontal cortex, posterior cingulate cortex, precuneus—and in visual and thalamic regions, even after adjusting for physiological differences between conditions. State Mindfulness Scale scores significantly increased after the meditation session and remained elevated at a two-week follow-up. The findings support that focused attention meditation attenuates default-mode activity linked to self-referential processing, establishing the feasibility of 7 Tesla fMRI for meditation research.
Neuroscience and Biobehavioral Reviews
September 1, 2026
Isabella Goodwin, Dominic Oliver, Edward Chesney et al.
A meta-analysis of 41 double-blind, placebo-controlled experiments involving 1,020 infrequent cannabis users found that acute THC administration increases feelings of high, anxiety, and tiredness, while decreasing alertness and contentedness, with no effect on calmness. Inhaled THC dose-dependently increased high and contentedness but decreased calmness, with greater consistency in high and contentedness at higher doses. On a 100-point scale, inhaling 5 mg THC increased high by 34.3 points, anxiety by 14.4, tiredness by 26.3, and calmness by 4.5, while decreasing alertness by 40.2 and contentedness by 71.0. Oral THC showed no significant subjective effects, though higher oral doses produced more consistent alertness. These findings can inform public health guidance on expected THC effects.
Substance Abuse and Rehabilitation
January 1, 2026
Ethan Murphy, Chao Suo, Govinda Poudel et al.
Acute intoxication with delta-9-tetrahydrocannabinol (THC) is consistently associated with greater brain activity in fronto-striatal pathways. Regular cannabis users, compared to non-users, show lower hippocampal volume, reduced white matter microstructure in the superior longitudinal fasciculus, and altered fronto-striatal activity and connectivity during cue-reactivity tasks and at rest. Emerging evidence from Positron Emission Tomography studies indicates lower N-acetyl aspartate, reduced glucose metabolism in the frontal cortex, and lower density of cannabinoid receptors in fronto-striatal pathways, which may reverse with abstinence. Longitudinal multimodal neuroimaging studies are needed to determine whether these brain differences precede or follow cannabis use and whether they dissipate with abstinence.
Neuroscience and Biobehavioral Reviews
October 1, 2022
Saampras Ganesan, Emillie Beyer, Bradford A. Moffat et al.
Focused attention meditation consistently engages three key functional brain networks: the Default-mode, Salience, and Executive Control networks. A quantitative meta-analysis of 10 functional MRI studies (200 participants) showed that meditation expertise, mindfulness levels, and attentional skills influence the magnitude, but not the regional extent, of activation and functional connectivity in these networks. A unified neurocognitive brain-network model of focused attention meditation is proposed.