bioRxiv
July 22, 2025
preprint
Psychedelics show potential for enhancing associative learning in animals, according to a systematic review of 31 studies (29 animal, 2 human). The review found that psychedelic administration improved learning across classical and operant conditioning paradigms, including fear extinction and reversal learning, though effects varied by dose, timing, training intensity, and sex. Possible mechanisms include increased prediction error sensitivity, serotonin receptor agonism, and structural plasticity. Learning enhancements may persist into the post-acute phase and depend on active environmental engagement. These findings have not yet been confirmed in humans, but suggest a window of enhanced learning that could inform psychedelic-assisted psychotherapy.
bioRxiv
April 21, 2025
preprint
After a single 12 mg dose of the psychedelic 5-MeO-DMT, people's speech patterns shifted toward more cognitive language and fewer social words, and their voices showed increased jitter and shimmer, indicating altered vocal quality. Baseline speech features predicted how psychologically prepared participants were, their anxiety about ego dissolution, emotional breakthrough, and later well-being. The findings suggest that analyzing voice journals can track a shift from external focus to introspection and serve as a tool for monitoring psychological transformation after psychedelic use.
bioRxiv
December 17, 2024
preprint
The default mode network (DMN) and frontoparietal control network (FPCN), typically anticorrelated at rest in healthy brains, show continuous rather than absolute anatomical boundaries in the posterior precuneus. Connectivity differences along the dorsal-ventral axis follow linear slopes, forming functional gradients that exist only within each network's territory. These gradients flatten in altered states of consciousness (ASC), with the gradient magnitude similarly impaired across different ASC types, while spatial entropy differs between psychedelic and sedative states. The findings suggest the DMN and FPCN, though appearing distinct, may originate from a single integrated mechanism, and the loss of functional differentiation between them characterizes altered conscious states.
bioRxiv
October 26, 2024
preprint
Practicing meditation from a third-person perspective in virtual reality, compared with a first-person perspective, produces stronger feelings of detachment and disconnection, a less distinct sense of one's body boundary, and reduced identification with the body. These subjective changes are accompanied by a more negative heartbeat evoked potential amplitude and activation of the posterior cingulate cortex and medial prefrontal cortex. The findings link altered states of self during meditation to neural and behavioral measures of the bodily self, demonstrating that manipulating perspective in VR can modulate the sense of self during meditation.
bioRxiv
January 29, 2024
preprint
The brain state induced by psychedelic drugs is often studied as a static snapshot, but this work focuses on the transition itself. Using a time-dependent whole-brain model and fMRI data from 15 volunteers given intravenous DMT, the authors show that the drug briefly pushes the brain near a critical point where it becomes maximally responsive to perturbations. This heightened reactivity is concentrated in fronto-parietal regions and visual cortices and correlates with serotonin 5HT2a receptor density. The findings suggest that even a short psychedelic episode can have a lasting influence because minimal perturbations during this transient achieve maximal effect, with the temporal evolution aligning with the drug's pharmacokinetics.
bioRxiv
December 7, 2023
preprint
A measure of 'statistical complexity' that calculates the diversity of statistical interactions in neural activity, removing randomness, was tested on human brain data from different sleep stages and from people under ketamine, LSD, and psilocybin. Statistical complexity differentiated sleep stages similarly to the standard Lempel-Ziv complexity measure and increased relative to placebo for all three psychedelic substances. The measure is a useful alternative for investigating neural activity complexity across states of consciousness.