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Jeremy I Skipper

Department of Experimental Psychology, University College London, London, UK.

7 papers in the library · 20 citations · publishing 2024-2026

Papers

Complex slow waves in the human brain under 5-MeO-DMT.

Cell reports July 22, 2025 George Blackburne, Rosalind G McAlpine, Marco Fabus et al. 10 citations

Inhaling a high dose of vaporized synthetic 5-MeO-DMT radically reorganizes low-frequency brain oscillations, making them heterogeneous, viscous, and nonrecurring, and halting their typical forward and backward travel across the cortex. This reorganization also causes broadband neural activity to become more stable and low-dimensional, with increased energy barriers for rapid global shifts. These findings, based on EEG data from 29 healthy individuals, provide a detailed account of how the drug sculpts human brain dynamics and reveal atypical cortical slow-wave behaviors relevant to neuroscientific models of serotonergic psychedelics.

Complex slow waves radically reorganise human brain dynamics under 5-MeO-DMT

bioRxiv (Cold Spring Harbor Laboratory) October 7, 2024 George Blackburne, Rosalind McAlpine, Marco S. Fabus et al. 8 citations preprint

A high dose of the psychedelic drug 5-MeO-DMT radically reorganizes low-frequency brain activity in 29 healthy individuals. Inhaling 12 mg of vaporized synthetic 5-MeO-DMT caused neural activity flows to become incoherent, heterogeneous, viscous, fleeting, and nonrecurring, ceasing typical traveling waves across the cortex. This reorganization led to slower, more stable, low-dimensional broadband activity with increased energy barriers to rapid global shifts. The findings provide the first detailed empirical account of how 5-MeO-DMT alters human brain dynamics, revealing novel cortical slow wave behaviors.

How to set up a psychedelic study: Unique considerations for research involving human participants.

Neuroscience and biobehavioral reviews July 1, 2026 Marcus J Glennon, Catherine I V Bird, Prateek Yadav et al. 2 citations

Setting up a psychedelic research study involves a long, arduous, and Kafkaesque process with many unstandardised challenges. These complexities challenge existing assumptions about psychiatric prescribing, the placebo effect, and definitions of selfhood. This review brings together major UK psychedelic research teams to formalise these unique considerations, addressing sociocultural, political, legal, pharmacological, safety, study design, and experiential facets. It identifies continuing areas of debate and provides a practical, experience-based guide with recommendations for policymakers and future researchers intending to set up a psychedelic study or clinical trial.

Speech markers of psychological change following a psychedelic 5-MeO-DMT retreat.

Journal of psychopharmacology (Oxford, England) May 23, 2026 Joanna Kuc, Rosalind G McAlpine, Amelia Sellers et al.

A short-acting psychedelic, 5-MeO-DMT, shifts speech from external focus to introspection. In 29 participants who kept daily voice journals two weeks before and after a single 12 mg dose, language analysis showed increased cognitive words and fewer social words, while vocal quality changed with more jitter and shimmer. Baseline speech patterns predicted how prepared people felt, the intensity of emotional breakthrough, and later well-being. This is the first longitudinal study showing that vocal journaling can track and predict psychological transformation around a psychedelic retreat, offering a framework for monitoring preparation and integration periods.

Digital Intervention for Psychedelic Preparation (DIPP): protocol for a randomised controlled feasibility trial comparing meditation- and music-based programmes in healthy volunteers.

BMJ open March 12, 2026 Rosalind McAlpine, Magdalena Jaglinska, Krisztina Jedlovszky et al.

A 21-day mobile-accessible programme called the Digital Intervention for Psychedelic Preparation (DIPP) is being tested for feasibility and preliminary efficacy in a randomised controlled trial. The study will recruit 40 non-treatment-seeking adults without a clinical diagnosis, randomly assigning them to either a guided meditation with music condition or a music-only condition. After the digital intervention, all participants will attend an in-person supervised psilocybin session with a standardised 25 mg dose. Primary outcomes include recruitment efficiency, retention, and adherence; secondary outcomes assess preparedness, quality of the psychedelic experience, and wellbeing, with follow-ups up to 9 months. The trial is registered as NCT06815653.

Understanding Neuroplasticity Induced by Tryptamines (UNITy): Understanding Neuroplasticity Induced by Tryptamines: Rewiring Maladaptive Memories in Hazardous Drinking with Memory Reactivation and Dimethyltryptamine (DMT)

Open Science Framework October 20, 2025 Natalia Fernandez-Vinson, Roger Atkins, Marcus Glennon et al.

This registered clinical study investigates whether N,N-dimethyltryptamine (DMT), alone or combined with reactivating alcohol-related memories, can produce lasting changes in the brain, cognition, and drinking behavior in people with mild alcohol use disorder who are hazardous drinkers but not seeking treatment. Up to 120 participants will be assigned to one of four groups: alcohol memory retrieval plus DMT, alcohol memory retrieval plus placebo, control memory retrieval plus DMT, or control memory retrieval plus placebo. Drinking levels will be measured over three lab sessions and a nine-month follow-up using timeline follow-back and blood tests.

Inner speech and the neurobiology of psychosis

bioRxiv Preprint Server August 22, 2025 Jeremy I Skipper, Daniel R Lametti, David W Green preprint

Psychotic symptoms such as hearing voices or feeling that thoughts are inserted may arise from failures in the brain's prediction and self-monitoring systems. Normally, when people talk internally, the brain sends copies of motor commands to auditory regions and suppresses them, helping distinguish self-generated from external input. When this suppression malfunctions, predicted inner speech can become perceptually salient and misattributed as external. Neuroimaging meta-analyses showed that psychosis-spectrum participants had increased activity in motor-related regions for inner speech and decreased grey matter in auditory cortices and anterior cingulate cortex. These regions form inversely coupled networks, supporting a hierarchical predictive-processing account where disruption distorts self-awareness.