Red-Light Multi-Modal Ganzfeld Elicits Equivalent Complex Imagery to Moderate-Dose Psilocybin: A Cross Study Comparison

Altered states of consciousness (ASCs) are multidimensional deviations from waking experience, that can be induced either pharmacologically or non-pharmacologically. While pharmacologically induced ASCs (e.g., psilocybin) are often presumed to be more intense, emerging work suggests that distinct induction types may produce states that overlap on some phenomenological features. We investigated whether a non-pharmacological method, red-light multimodal Ganzfeld (MMGF), can elicit experiences phenomenologically comparable to those induced by moderate-dose psilocybin, particularly regarding the factor of complex imagery. Participants in two separate studies completed the 5D-ASC: (1) 0.17 mg/kg psilocybin (n=21, double-blind; Mason et al., 2020), and (2) red-light MMGF (n=33, deception-based blinding). Non-parametric tests were used due to violation of normality assumptions in the MMGF group. Moderate-dose psilocybin induced significantly greater overall ASC intensity (G-ASC), especially in Oceanic Boundlessness and Visionary Restructuralization (Mann-Whitney p < .01). However, Complex Imagery, an experiential factor of clinical and theoretical interest, did not significantly differ (p = .207, Cliff’s δ = −0.20). Non-parametric equivalence testing confirmed this equivalence, with the entire plausible median range falling within a conservatively defined smallest effect size of interest (±9 VAS points; Meier, 2010). While moderate-dose psilocybin generates a more intense overall ASC, red-light MMGF induces complex imagery experiences phenomenologically equivalent in intensity. This supports MMGF as a viable, non-pharmacological method to study and potentially leverage hallucinatory phenomena in clinical or cognitive settings. Future work should test both conditions under matched protocols to confirm our findings and test the effects of their combination in a “hybrid-induction” ASC.