Stroboscopic Light Stimulation Safety Within and Beyond Laboratory Settings: Observational Evidence and Practical Guidance

medRxiv

Abstract

Abstract Stroboscopic light stimulation (SLS) reliably evokes geometric visual hallucinations and, in some contexts, altered-state experiences. Its increasing use in research, public, recreational and exploratory clinical settings creates a need for proportionate safety guidance. The main concern is a visually triggered seizure in a susceptible individual; reported non-epileptic responses include discomfort or distress. We combined a retrospective survey of safety practices and reported events across four laboratories, provider-reported operational data from two commercial SLS platforms, and a focused review of photosensitivity and sensory intolerance. Laboratory contributors reported 20 non-serious events that interrupted or modified participation, with no reported seizures or syncopal episodes. One commercial provider reported nine medically important or otherwise notable events across approximately 3.8 million sessions. The other reported five such events across more than 400,000 sessions. Because commercial adverse-event capture was passive and the laboratory protocols and monitoring procedures were heterogeneous, these figures cannot be used to estimate incidence or establish screening effectiveness. This synthesis informed a provisional Sussex Strobe Safety Screening Questionnaire (4SQ) and a layered, context-specific risk-management approach. The resulting framework distinguishes non-serious tolerability concerns from the principal medical risk of a visually provoked seizure in a susceptible individual, and supports conservative monitored familiarisation exposure, immediate stopping procedures and systematic adverse-event surveillance. The predictive performance of the 4SQ and the effectiveness of these precautions require formal evaluation; absolute SLS risk remains uncertain.

Authors 13

1. David J. Schwartzman corresponding

   University of Sussex

   Affiliation as printed

   Sussex Centre for Consciousness Science and School of Engineering and Informatics, University of Sussex, UK

   University of Sussex

2. Trevor Hewitt

   University of Sussex

   Affiliation as printed

   Sussex Centre for Consciousness Science and School of Engineering and Informatics, University of Sussex, UK

   University of Sussex

3. Timo Torsten Schmidt

   MSB Medical School Berlin · Freie Universität Berlin

   Affiliation as printed

   CIRCE - Collaboration for Interdisciplinary Research on Conscious Experience e.V., Teupitz, Germany

   MSB Medical School Berlin, Institute of Neuroscience and Biopsychology for Clinical Application (INBICA), Rüdesheimer Straße 50, 14197 Berlin, Germany

   Freie Universitat Berlin

4. Josemir W. A. S. Sander

   University of Sussex · Sichuan University · West China Hospital of Sichuan University · UCL Queen Square Institute of Neurology · University College London

   Affiliation as printed

   Department of Neurology, West China Hospital, Sichuan University, Chengdu 610041, China

   UCL Queen Square Institute of Neurology, London WC1N 3BG

   University of Sussex

5. Danny Nacker

   University of Sussex · Macquarie University

   Affiliation as printed

   Sussex Centre for Consciousness Science and School of Engineering and Informatics, University of Sussex, UK

   Macquarie University, Sydney, Australia

6. James Thurbon

   Macquarie University

   Affiliation as printed

   Macquarie University, Sydney, Australia

7. Vince Polito Aachen

   Leiden University · Macquarie University

   Affiliation as printed

   Macquarie University, Sydney, Australia

   Leiden University, Leiden, the Netherlands

8. Xaver Funk Aachen Faculty of Social and Behavioural Sciences

   Leiden University · University of Glasgow

   Affiliation as printed

   Faculty of Social and Behavioural Sciences, Leiden University, Leiden, the Netherlands

   University of Glasgow, UK

9. Fiona Macpherson

   UCL Queen Square Institute of Neurology · University College London · University of Glasgow

   Affiliation as printed

   Centre for the Study of Perceptual Experience, University of Glasgow, UK

   UCL, Queen Square Institute of Neurology, London, U.K

10. Tom Galea
    Affiliation as printed

    Lumenate Growth Ltd, Bristol, UK

    Lumenate Growth Ltd

11. J. R. Simpson
    Affiliation as printed

    Roxiva Innovations Ltd, Sheffield, UK

    Roxiva Innovations Ltd

12. Romy Beauté

    University of Sussex

    Affiliation as printed

    Sussex Centre for Consciousness Science and School of Engineering and Informatics, University of Sussex, UK

    University of Sussex

13. Anil K. Seth

    Canadian Institute for Advanced Research · University of Sussex

    Affiliation as printed

    Program for Brain, Mind, and Consciousness, Canadian Institute for Advanced Research, Toronto, Canada

    Sussex Centre for Consciousness Science and School of Engineering and Informatics, University of Sussex, UK

    University of Sussex