A Comparative Neurophenomenology of the Psychedelic State and Autism: Predictive Processing as a Unifying Lens

Serotonergic psychedelics, particularly psilocybin, lysergic acid diethylamide (LSD), and dimethyltryptamine (DMT), are increasingly recognised as powerful tools to advance the understanding of consciousness and its relation to brain activity. Psychedelic research has informed neuroscientific theories that attempt to map neural observations of network connectivity and signal diversity to phenomenological qualities like psychological flexibility. Thus far, however, there have been relatively limited efforts to bridge the gap between psychedelic-informed theory and the experiential differences observed in neurodevelopmental conditions such as autism. In this narrative review and conceptual synthesis, we compare the psychedelic state and autism in adults from a neurophenomenological perspective. Predictive processing is invoked as a unifying framework. This procedure highlights both phenomena as involving a shift towards sensory information relative to prior knowledge, but potentially implicating alterations at opposite ends of the cortical hierarchy. This contrastive approach also reveals opportunities for refining concepts-including psychological flexibility-as well as interpretations of results across fields. However, neurobiological findings, especially in autism, are heterogeneous and there are inherent restrictions in comparing transient state and lifelong trait phenomena. Conclusions of this comparison are primarily conceptual and offer testable hypotheses for the neurophenomenology of the psychedelic state, autism, and their interaction.