UC Berkeley To Enlist Human Subjects in Groundbreaking Psilocybin Study

University of California, Berkeley (UC Berkeley) will observe human subjects in a study to determine if psilocybin, the active compound in magic mushrooms.The study marks UC Berkeley’s first study involving human subjects with a Schedule I substance—drugs with no currently accepted medical value. 

The study will examine how psilocybin changes the way our brain interprets information that we see and pushes us out of our normal state of mind. The UC Berkeley Center for the Science of Psychedelics (BCSP) is launching a new study designed to reveal the mechanisms behind how psychedelics shape human perception. 

In the experiment, healthy human participants will ingest psilocybin, a compound found in psychedelic mushrooms. All the while, researchers will observe how their brains light up. Each participant will then perform simple perceptual tasks while their visual cortex is monitored using functional Magnetic Resonance Imaging (fMRI). 

“We have this incredible opportunity to characterize the psychedelic experience in real time—while it’s happening—using modern neuroimaging methods,” Michael Silver, director of the BCSP and the study’s leader, told Berkeley News. “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 treatments for mental health disorders. It will also shed light on some of the fundamental mysteries of the human brain, mind and consciousness and how they relate to each other.”

Before this study, UC Berkeley researchers had to rely on animal subjects, typically mouse models, in order to study psilocybin as a Schedule I substance. Going beyond that usually requires DEA approvals.

For the BCSP, they had to work for years to acquire federal, state, and campus-level regulatory approvals in order to use psilocybin, and they must follow stringent rules for handling of it.

How Psilocybin Shapes the Way We Perceive Visual Information

Silver explained to Berkeley News in detail what excites him about the way psilocybin changes the way we see and process visual information.

Silver explained that our retina pick up about as much info and/or resolution as a 2007 camera—but our brains fill in the blanks, providing rich detail. “The way that we perceive the world is very unlike a video camera,” Silver said. “While a camera just passively records whatever comes through the lens, our brain takes that sensory information from the eyes and combines it with previous experiences to generate our conscious experience of the world. We make implicit assumptions—for example, that objects that are in one place tend to stay in one place, or that objects that are moving tend to continue moving along that trajectory—to help construct our perceptions.”

“Our area of interest is the visual system in the brain,” Silver told CBS News. “Psychedelics are a wonderful tool for understanding this.”

UC Berkeley’s Center for the Science of Psychedelics is underway and staff are recruiting volunteers, center director and UC Berkeley professor Michael Silver said.

“My love is science, not the administrative part of it,” Silver said. “I understand the importance of that, but the reason I am personally motivated to do this is to learn about the brain and to learn about the visual system and how we create conscious experience.”

“Visual priors” help define how our brain interprets information we see. In the new experiment supported by the BCSP, researchers will observe how psilocybin impacts visual perception and how these perceptions are generated in the brain. They plan to test a hypothesis known as REBUS, or relaxed beliefs under psychedelics, which proposes that psychedelics work by “relaxing” assumptions, so that our perceptions are shaped less by visual priors and more by raw sensory information. 

Psychedelic-assisted therapy is gaining traction because of the ability of psychedelics to push people out of mental patterns.

“If you think about the disorders where we have the best evidence that psychedelics can be a useful therapy, including PTSD, depression, anxiety and various substance use disorders, they often involve a maladaptive prior or belief, such as a negative self-image,” Silver said. “The REBUS theory proposes that psychedelic-assisted therapy works by reducing the influence of these priors, followed by construction of healthier priors through psychotherapy.”

The team hopes that the information they glean will help to better understand how our minds perceive information and how psilocybin impacts those abilities.

“We know a great deal about the different structures and neural types in the visual system, and as a result, we have some understanding of what visual priors and sensory information look like in the brain, and how they interact with each other,” Silver said. “And so, using functional magnetic resonance imaging, we can test this theory in a very rigorous way.”