How Psychedelic Drugs Affect the Brain

OG article by Meike Drießen

February 13, 2026

New research illuminates the neurological effects of psychedelic substances, showing how they shift brain activity to produce hallucinations and altered perception. A team from Hong Kong, Singapore, and Ruhr University Bochum used high-resolution imaging in an animal model to observe changes after psychedelic administration.

Psychedelics primarily target the serotonin 2A receptor, suppressing visual processing and reducing access to external sensory input. To compensate, the brain draws on memory fragments, creating hallucinations. The study found intensified low-frequency oscillations in visual areas that activate the retrosplenial cortex, a hub for memory and associations.

This shifts perception toward internally generated content, resembling a dream-like state. The findings, published in Communications Biology, support supervised psychedelic therapy for conditions like depression and anxiety by enabling recall of positive memories to reframe negative patterns.

Using genetically modified mice with fluorescent markers, researchers tracked real-time activity in specific cortical layers. These insights advance understanding of consciousness and potential personalized therapeutic applications under medical guidance.