Space Oddity: microgravity as a neurocognitive catalyst for transformative consciousness experiences

Human consciousness has evolved under the constant pull of terrestrial gravity, yet its role in shaping perception and awareness has received limited theoretical attention. As spaceflight transitions from short missions to long-duration habitation, understanding how consciousness responds to non-terrestrial gravity becomes increasingly urgent. In this perspective, we synthesise behavioural, neurophysiological and neuroimaging evidence to argue that Earth's gravity functions as a deeply entrenched 1G super-prior within the brain's predictive architecture. This super-prior stabilises multisensory integration and constrains large-scale brain network organisation. Exposure to microgravity disrupts vestibular reliability, destabilising this super-prior and triggering cascades of prediction errors that necessitate widespread recalibration across cortical and subcortical systems. We show that these processes extend beyond sensorimotor adaptation, reshaping conscious experience through altered self-location, emotional regulation and perceptual coherence, and potentially underpinning transformative phenomena. Drawing computational parallels with psychedelic states, we propose that microgravity constitutes a non-pharmacological perturbation that transiently relaxes high-level priors, loosens hierarchical constraints and enhances global integration. By situating consciousness in an environment for which evolution offers no precedent, spaceflight provides a unique experiment for probing the contingent foundations of human awareness and the mechanisms through which consciousness can be transformed.