Journal of Psychopharmacology
May 20, 2006
Marc Wittmann, Olivia Carter, Felix Hasler et al.
245 citations
Psilocybin impairs the ability to reproduce time intervals longer than 2.5 seconds, to synchronize movements to beats longer than 2 seconds, and slows preferred tapping rate. These objective timing deficits are accompanied by working-memory impairments and subjective changes including depersonalization and derealization. The findings indicate the serotonin system is selectively involved in processing durations longer than 2–3 seconds and in voluntary movement speed control. The disruption of longer intervals likely results from interactions with cognitive dimensions of temporal processing via 5-HT2A receptor stimulation.
Biological Psychiatry
December 4, 2010
Michael Kometer, B. Rael Cahn, David Andel et al.
101 citations
The hallucinogenic compound psilocybin, which activates 5-HT2A/1A serotonin receptors, alters how the brain processes visual information. In a placebo-controlled experiment with 17 healthy volunteers, psilocybin dose-dependently reduced the N170 brain response, especially when viewing incomplete object figures, while slightly enhancing the P1 component over occipital areas. The reduction in N170-related brain activity in the right extrastriate and posterior parietal regions correlated with the intensity of visual hallucinations. These findings point to a central role of 5-HT2A/1A receptors in visual processing and suggest that a diminished N170 response may be a key mechanism underlying visual hallucinations.
bioRxiv (Cold Spring Harbor Laboratory)
June 20, 2020
Jacob van Doorn, Mengqi Xing, B. Rael Cahn et al.
1 citation
preprint
Brain connectivity patterns differ between meditation states and instructed mind-wandering, regardless of meditation experience or tradition. Experienced meditators from Isha Yoga, Himalayan Yoga, and Vipassana traditions, along with meditation-naïve individuals, performed breath awareness, autobiographical thinking, and their own meditation practice while 64-electrode EEG recorded brain activity. A new method called Thought Chart mapped each person's dynamic functional connectivity. Both breath awareness and meditation tasks showed consistently different connectivity patterns compared to mind-wandering, measured by Hausdorff distance. The meditation state most closely resembled breath awareness across all groups. These differences were not driven by specific frequency bands, and no significant group differences emerged.
arXiv (Cornell University)
November 26, 2025
Jonas Mago, Josh Brahinsky, Mark Miller et al.
During a 10-day retreat, ten experienced meditation practitioners showed that neural dynamics can be volitionally shifted toward a critical regime—a state between order and chaos that supports flexible yet stable information processing. Compared to regular mindfulness of breathing, a refined state of meditative absorption called jhana produced pronounced sensory fading, slower respiration, higher neural signal diversity, reduced chaoticity, and enhanced mismatch negativity amplitude over frontocentral sites. Spectral analyses revealed a flatter aperiodic component and reorganization of long-range temporal correlations. These findings suggest that criticality is a candidate neurophysiological marker of absorptive, minimal-content experiences.
The Oxford Handbook of Meditation
December 15, 2020
Kieran C. R. Fox, B. Rael Cahn
Meditation is associated with changes in brain structure and function. Structural imaging shows alterations in grey and white matter. Functional imaging (fMRI, PET) reveals distinct brain activity patterns during different meditation practices, how meditation alters responses to tasks, and how long-term meditators' expertise can illuminate cognition. Electrophysiological measures (EEG) complement these findings. Meditation may offset cognitive aging deficits and help ameliorate symptoms and neural substrates of neurodegenerative and psychiatric diseases.