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Kim van Oorsouw

Department of Clinical Psychological Science, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, Netherlands.

4 papers in the library · 37 citations · publishing 2023-2026

Papers

Shared functional connectome fingerprints following ritualistic ayahuasca intake.

NeuroImage January 1, 2024 Pablo Mallaroni, Natasha L Mason, Lilian Kloft et al. 17 citations

Brain functional connectomes are unique fingerprints that persist across mental states, but their stability under altered states is unknown. After collective ayahuasca intake in 21 Santo Daime members, 7T fMRI showed reduced idiosyncrasy in static and dynamic functional connectivity, with a spatiotemporal reallocation of keypoint edges. Interindividual differences in higher-order connectivity motifs predicted perceptual drug effects, demonstrating that individualized connectivity markers can trace a subject's functional connectome across altered states of consciousness.

Altered State of Consciousness and Mental Imagery as a Function of N, N-dimethyltryptamine Concentration in Ritualistic Ayahuasca Users

Journal of Cognitive Neuroscience January 1, 2023 Johannes G Ramaekers, Pablo Mallaroni, Lilian Kloft et al. 15 citations

In members of the Santo Daime church who regularly consume ayahuasca in a ritual setting, the brew's main psychoactive compound DMT drives feelings of oceanic boundlessness, visual restructuring, and ego dissolution, with these effects correlating with peak DMT concentration in the blood. However, measures of mental imagery—including visual perspective shifting, vividness of imagery, and associative thinking—did not noticeably differ between sober and ayahuasca conditions, though subjective cognitive flexibility was lower under ayahuasca. Two mental imagery measures (perspective shifts and cognitive flexibility) correlated with peak DMT levels. Long-term ayahuasca use may produce compensatory or neuroadaptive effects that dampen the acute impact on mental imagery.

Ayahuasca enhances the formation of hippocampal-dependent episodic memory without impacting false memory susceptibility in experienced ayahuasca users: An observational study.

Journal of psychopharmacology (Oxford, England) April 1, 2025 Manoj K Doss, Lilian Kloft, Natasha L Mason et al. 5 citations

In experienced users, ayahuasca acutely enhances recollection-based memory—the ability to recall specific details—without increasing false memories or affecting familiarity-based memory, a feeling of knowing. In an observational study of 24 Santo Daime members who had consumed ayahuasca over 500 times on average, participants completed a false memory task before and after taking a self-selected church dose. After ayahuasca, hit rates, memory accuracy, and recollection improved, while familiarity and false memory remained unchanged. The authors suggest that β-carboline activity in the brew may account for this recollection enhancement, which contrasts with past psychedelic research showing impaired recollection. Practice effects could not be ruled out, but multiple measures of false memory and metamemory did not improve across sessions.

Brain-body integromics of the ayahuasca experience.

Biomedicine & pharmacotherapy = Biomedecine & pharmacotherapie June 1, 2026 Francisco Madrid-Gambin, Pablo Mallaroni, Noemí Haro et al.

The psychedelic state induced by ayahuasca arises from coordinated, system-level interactions between peripheral metabolism and brain network dynamics, rather than isolated neurochemical events. In 20 experienced ceremonial users, the subjective dimensions of oceanic boundlessness, visionary restructuralization, and auditory alterations covaried with circulating DMT and β-carbolines, shifts in lipid, amino acid, and energy metabolism, and reconfiguration of dorsal attention and default mode network connectivity. Shared features across these experiences were most strongly linked to endocannabinoid-related N-acylethanolamines, acylglycerols, and ceramides, extending beyond canonical serotonergic models to downstream lipid-signaling and metabolic processes. The findings offer translational insight into metabolic pathways that may modulate brain function and subjective response.