Scott reviews Julian Jaynes' controversial theory that ancient people lacked consciousness and instead heard hallucinated voices of gods, critiquing some aspects while finding value in the idea of theory of mind as culturally constructed. Longer summary

Scott reviews Julian Jaynes' book 'The Origin Of Consciousness In The Breakdown Of The Bicameral Mind'. The book argues that ancient people lacked theory of mind and instead heard hallucinatory voices they interpreted as gods giving them commands. Jaynes traces the development of consciousness through ancient texts, showing how mental processes were described differently before and after this shift. Scott critiques some aspects of Jaynes' theory but finds value in the idea that theory of mind is culturally constructed and can vary significantly between groups. Shorter summary

Scott Alexander investigates the prevalence of Hallucinogen Persisting Perceptual Disorder (HPPD) and explores potential connections between perception, cognition, and belief in supernatural phenomena. Longer summary

Scott Alexander explores the prevalence and nature of Hallucinogen Persisting Perceptual Disorder (HPPD), a condition where people experience ongoing visual disturbances after using psychedelics. He discusses results from his own survey, which found that about 12.8% of psychedelic users reported some persisting hallucinations, with 3% still experiencing them. Most cases were mild, involving visual snow, halos, or patterns. Scott then critiques a study claiming HPPD doesn't exist, noting methodological issues. He also considers the possibility that some people naturally experience HPPD-like phenomena without drug use, and speculates on potential links between perception, cognition, and belief in supernatural phenomena. Shorter summary

Scott Alexander hypothesizes that mystical experiences, hallucinations, and paranoia might be linked to an overactive pattern-matching faculty in the brain. Longer summary

Scott Alexander explores the relationship between mysticism, pattern-matching, and mental health. He suggests that hallucinations, paranoia, and mystical experiences might all be related to an overactive pattern-matching faculty in the brain. The post begins by discussing how the brain's failure modes differ from computers, then explains top-down processing and pattern matching using visual examples. It then connects these concepts to hallucinations, paranoia, and mystical experiences. Scott proposes that certain practices like meditation, drug use, and religious rituals may strengthen the pattern-matching faculty, leading to experiences of universal connectedness or enlightenment. He acknowledges that this hypothesis doesn't explain all aspects of mystical experiences and their benefits. Shorter summary

Scott Alexander presents a roundup of recent scientific and medical studies, covering topics from hallucinations to obesity genetics to schizophrenia treatment. Longer summary

This post is a collection of various scientific and medical studies and news. It covers a range of topics including hallucinations, diet and longevity, gene-environment interactions in psychiatry, life-extending drugs, fibromyalgia, chemical education, drug company tactics, sleep theories, psychotherapy effectiveness, obesity genetics, and schizophrenia treatment. Scott provides brief summaries and commentary on each item, often with a mix of scientific insight and humor. Shorter summary