Synthetic surprise as the foundation of the psychedelic experience
Neuroscience & Biobehavioral Reviews January 15, 2024 Dietmar Schmitz, Roberto de Filippo 13 citations
Psychedelic agents like LSD and psilocybin alter consciousness by activating the 5-HT2A receptor. The authors hypothesize that these drugs enforce a state of synthetic surprise through biased activation of the 5-HT receptor system, drawing on recent insights into serotonin's role in signaling surprise. Within the predictive coding framework, surprise corresponds to prediction error—the mismatch between predictions and sensory input. The precision of prediction error determines its effect on priors, allowing dynamic interaction between top-down expectations and incoming data. Integrating findings on predictive coding circuitry and 5-HT2A receptor transcriptomic data, the authors propose a biological implementation emphasizing inhibitory interneurons. This has implications for clinical use, where psychedelics may disrupt maladaptive patterns by inducing surprise.