bioRxiv (Cold Spring Harbor Laboratory)
February 18, 2026
Ethan Grove, Trevor Hewitt, Anil K. Seth et al.
1 citation
Visual hallucinations (VHs) occur in psychedelic states and various psychiatric and neurological conditions, but their phenomenology is hard to characterize due to a lack of large-scale datasets. Stroboscopic light stimulation (SLS) with closed eyes reliably induces VHs in healthy people, producing vivid colors and dynamic geometric patterns similar to simple VHs in other contexts. Researchers developed an unsupervised computer-vision pipeline to analyze 10,598 drawings made after hallucination-inducing SLS at a public installation. Most drawings contained geometric forms, consistent with prior observations, but novel patterns like concentric squares, crosses, and hyperbolic shapes also appeared. The pipeline organized the drawings into interpretable classes, mapping the diversity of simple geometric VHs and placing new constraints on theoretical accounts.
medRxiv Preprint Server
June 17, 2026
Danny Nacker, Luise Kalus, Anil K. Seth et al.
preprint
Supervised stroboscopic light stimulation (SLS) was safe, tolerable, and feasible in adults with depressive symptoms, but efficacy was not established. In a staged program, 31 participants tested 11 SLS parameter sets; no severe adverse reactions occurred, and mean discomfort was low (0.49 out of 10). A subsequent randomized trial assigned 84 participants to four weekly 31-minute sessions of SLS or a low-phenomenology control. Retention was 83.3% (70 of 84 participants), with higher retention in the intervention arm (39 of 42) than the control arm (31 of 42). Exploratory depressive-symptom changes suggested a possible signal on the BDI-II but do not confirm efficacy. The next step is a Phase 2a feasibility trial with a locked protocol.
arXiv Preprint Archive
February 25, 2025
Romy Beauté, David J. Schwartzman, Guillaume Dumas et al.
Stroboscopic light stimulation on closed eyes typically induces simple visual hallucinations—vivid, geometric, and colorful patterns. An analysis of 862 open-ended reports from the Dreamachine immersive experience, using large language models and topic modeling, confirmed these simple hallucinations and also revealed altered states of consciousness and complex hallucinations. This computational approach enables systematic study of subjective experiences beyond standard questionnaires, capturing subtle patterns not readily identified through closed-form questions. The findings broaden understanding of stroboscopically induced phenomena and demonstrate the potential of natural language processing in computational neurophenomenology.