Stroboscopic light stimulation as a controllable probe of the psilocybin state: a mechanistic framework and a falsifiable prediction.

Stroboscopic light stimulation (SLS) and psilocybin each induce altered states whose phenomenology and neurophysiology partly overlap, including posterior alpha-band changes and visual imagery. The two states engage the alpha band through different operations - pharmacological suppression under psilocybin and frequency-selective visual drive under SLS. We formalize their possible interaction for prediction and falsification. The framework proposes that, by relaxing the precision weighting of high-level cortical priors and, through 5-HT2A activation, suppressing posterior alpha-band power, psilocybin creates a state in which an exogenous, frequency-controlled visual rhythm can modulate the perceiver's experience. The thesis concerns precision rather than response amplitude. Because existing neuroimaging comes mostly from eyes-closed rest, where directional evidence is contested, the falsification does not depend on which sensory-inclusive model, Relaxed Beliefs Under Psychedelics (REBUS) or cortico-striatal-thalamo-cortical (CSTC), is correct. The framework predicts that, within a prespecified near-peak psilocin window, rhythmic SLS raises the Visionary Restructuralization dimension of the five-dimensional Altered States of Consciousness questionnaire (5D-ASC) relative to a luminance- and rate-matched arrhythmic control - an increase a precision framework predicts even if evoked amplitude does not rise. A complementary, report-independent endpoint, the intermodulation response to two-frequency stimulation, is proposed. State-dependence is tested as the drug-by-rhythmicity interaction in a 2 × 3 factorial design (placebo or psilocybin × rhythmic SLS, arrhythmic control, or no stimulation), with the sign of any interaction evaluated on a pre-declared scale. An adequately precise negative interaction would count against the central state-dependence prediction for the tested conditions. The framework organizes five axes around this prediction: titration of experiential intensity at fixed dose, content shaping through frequency specificity, modulation of difficult-experience phenomenology, testing whether resting-state signatures depend on sensory context, and individual-difference profiling of SLS responsiveness. The framework makes no claim of therapeutic enhancement. Its aim is mechanistic and methodological.