teaches neurobiology, psychology, and cognitive science at the University of California in Berkeley, and worked for many years in the clinical treatment of addiction at the San Francisco VA Medical Center.
Psychedelics are among the most powerful, interesting, and poorly understood of all the psychoactive substances. They produce a variety of complex effects on the brain and mind, including intensification of thoughts and feelings, alterations of sensory perception, and loosening of psychological defenses. As such, psychedelics probe the connection between brain physiology and consciousness, perhaps the most deeply mysterious arena in contemporary science. In their plant and fungal forms, psychedelics have been used by humans for millennia for medicinal and spiritual purposes.