Journal of Psychopharmacology
June 3, 2019
Yuliya Zaytseva, Jiřı́ Horáček, Jaroslav Hlinka et al.
25 citations
Delta-9-tetrahydrocannabinol, the active compound in cannabis, temporarily alters how brain regions communicate with each other. In 19 occasional cannabis users who underwent two resting-state fMRI scans—one shortly after smoking a cannabis cigarette and one after at least a week without cannabis—a transient connectivity state appeared only during intoxication. This state showed high connectivity within and between auditory and somato-motor cortices, along with anti-correlation with subcortical structures and the cerebellum. Subjective perceptual changes and THC plasma levels were linked to this state, suggesting a neural biomarker of cannabis intoxication.
bioRxiv (Cold Spring Harbor Laboratory)
July 16, 2026
Filip Novický, Nikola Jajcay, Jaroslav Hlinka
Neural avalanches—bursts of coordinated brain activity—are typically studied using scale-free statistics, but their detailed spatiotemporal structure and recurrence have been difficult to analyze due to variability in duration and spatial extent. A new method using flexible alignment with unbalanced optimal transport and subsequence dynamic time warping allows comparison of events of different lengths and configurations. Applied to 64-channel EEG data from 63 participants in the PsiConnect psilocybin study, hierarchical clustering revealed 12 recurring propagation patterns. Under psilocybin, oscillating sequences—those with alternating polarity and spatial propagation—were reduced relative to stable sequences, shifting the balance toward stable patterns. This effect was confirmed by a permutation test and largely driven by one cluster, indicating specific neural dynamics temporally affected by psilocybin.
bioRxiv (Cold Spring Harbor Laboratory)
June 12, 2026
Nikola Jajcay, Čestmír Vejmola, Jakub Korčák et al.
Psilocybin accelerates the temporal dynamics of large-scale brain activity while preserving access to the normal repertoire of brain states. In a double-blind, placebo-controlled crossover study of 15 healthy volunteers, EEG microstate analysis revealed that psilocybin increased the number of global field power peaks and reduced microstate lifespan while increasing their frequency of occurrence during peak intoxication (50–100 minutes after administration), indicating faster transitions between brain states. Microstate coverage was largely unchanged except for a transient difference in the 2–20 Hz bandwidth. Individual differences in these microstate dynamics correlated with both acute subjective experience intensity and self-reported psychological changes 28 days later, suggesting EEG microstates as candidate neural markers linking acute psychedelic effects to longer-term outcomes.
Psychopharmacology
December 13, 2025
David Greguš, Jaroslav Hlinka, Filip Tylš et al.
The spatial organization of the cingulate cortex, rather than the thickness of a single region, predicts the intensity of psychedelic experiences under psilocybin. In a double-blind, placebo-controlled crossover study with 25 healthy participants, an anterior–posterior gradient in cingulate thickness significantly predicted psychedelic experience intensity. The previously reported finding that rostral anterior cingulate cortex thickness alone predicts emotional responses showed a comparable effect size but did not reach statistical significance, likely due to the smaller sample size. These results suggest that the pattern of cortical thickness across the cingulate cortex, not focal measures, serves as a neuroanatomical marker of variability in psychedelic response.
bioRxiv Preprint Server
October 31, 2025
Tomas Hampejs, David Tomecek, Stanislav Jiricek et al.
preprint
Spontaneous, naturally occurring thoughts have distinct brain signatures that can be detected with combined fMRI and EEG recordings. Using machine learning on 240 samples from eight participants, internally versus externally oriented experiences were distinguished with 65.4% accuracy by fMRI and 62.5% by EEG. Externally oriented states involved greater activity in salience, auditory, and visuospatial brain networks and lower occipital alpha power, while internally oriented states showed the opposite pattern, extending prior accounts focused on the default mode network. Across modalities, alpha power correlated negatively with BOLD fluctuations in parietal and occipital regions, indicating that coordinated large-scale network dynamics and alpha oscillations track the natural alternation between inward and outward focus.
Research Square
September 25, 2025
David Greguš, Jaroslav Hlinka, Filip Tylš et al.
Individual differences in how people respond to psilocybin are linked to the structural organization of the cingulate cortex. A previous finding that thickness of a specific cingulate region predicted emotional responses was not replicated. Instead, a broader anterior-to-posterior gradient of cingulate thickness predicted the overall intensity of the psychedelic experience, and general cingulate thickness was associated with the balance between anxiety and visionary states. These results suggest that patterns of cortical thickness across the cingulate, rather than a single region, may serve as a neuroanatomical marker for predicting psychedelic response, with potential implications for personalized dosing in therapy.