Paper Ties Astronauts’ Mental Shifts to 1G Loss, Echoing Psychedelic States

1 articles · Updated · spacedaily.com · Jul 14

A Frontiers in Psychology Perspective argues astronauts’ altered sense of self after spaceflight may stem from losing Earth’s constant 1G gravitational cue, forcing the brain to rebuild core expectations.
The authors frame gravity as a lifelong “super-prior” in predictive processing: remove it in orbit, and unresolved vestibular and sensory prediction errors could loosen high-level models of body position and selfhood.
Evidence cited comes from earlier studies, not new experiments, including enlarged brain ventricles after long missions, altered vestibular connectivity after 169 days in orbit, and default-mode activity changes lasting up to 20 days after landing.
The paper says the resemblance to psychedelics is computational rather than mechanistic—microgravity may relax top-down priors in a way that partly mirrors LSD or psilocybin, without implying space acts like a drug.
Because the article is a hypothesis paper built on prior scans and astronaut reports, the claim remains unproven and awaits direct testing on future long-duration crews.