Ketamine and Psilocybin Differentially Impact Sensory Learning During the Mismatch Negativity
bioRxiv (Cold Spring Harbor Laboratory) November 7, 2025 Gabrielle Allohverdi, Milad Soltanzadeh, André Schmidt et al. preprint
Ketamine and psilocybin, two hallucinogenic compounds being explored as treatments for major depressive disorder, affect sensory learning in the brain differently. By combining computational modeling with electroencephalography (EEG) data from a prior experiment, researchers analyzed how these drugs alter the brain's processing of unexpected sounds during an auditory task. Ketamine produced a larger reduction in the influence of sensory precision between 207 and 316 milliseconds after a sound, peaking at 277 milliseconds in frontal central brain regions, while psilocybin showed no significant effect in that measure. Both drugs reduced the expression of belief precision between 160 and 184 milliseconds, peaking at 172 milliseconds.