“Our everyday experience is that we simply record the world around us with our eyes, but this is actually an illusion created by our brain,” says Professor Michael Silver, faculty director of the UC Berkeley Center for the Science of Psychedelics (BCSP).
Now Silver is leading a study that for the first time in Berkeley’s history will include administering a psychedelic substance to human subjects. Silver and fellow BCSP researchers will examine how psilocybin, a chemical found in “magic mushrooms,” shapes human perception and affects the brain’s use of past experiences, or “priors,” to create visual perception.
The study will test aspects of an influential idea about how the brain combines priors with other types of information to generate internal models of the world, revising them as necessary using new information. This theory, relaxed beliefs under psychedelics (REBUS), posits that psychedelics reduce the influence of priors in how the brain constructs conscious experiences.
According to the theory, the researchers should detect a shift in perception and brain processing away from dominant priors and toward more raw sensory perceptual interpretations.
For the first time in Berkeley’s history, a study will administer a psychedelic substance to human subjects to examine how it shapes human perception and affects the brain’s use of past experiences.
Silver and his colleagues obtained FDA approval to enroll up to 80 study participants. The team is using functional Magnetic Resonance Imaging (fMRI) technology to monitor their subjects’ visual cortex as they perform perceptual tasks after ingesting psilocybin. Initial research results are expected by the end of 2025.
Like all of the BCSP’s programs, this research is wholly supported by private philanthropy. The BCSP believes that its basic research will likely provide insights for clinical studies on psychedelics as potential therapeutics for mental health disorders. Beyond gaining knowledge about the psychedelic experience in real time in a well-studied system of the brain, the study could inform how psychedelic-assisted therapy enables psychiatric patients to address PTSD, depression, and anxiety.
Says Silver, “Understanding the actions of psychedelics at a neuroscientific level will generate insights into how they’re working as medicines and will hopefully help us develop more effective and precise treatments for mental health disorders.”
