Hemispheric annealing and lateralization under psychedelics (HEALS): A novel hypothesis of psychedelic action in the brain.

This article introduces the Hemispheric Annealing and Lateralization Under Psychedelics (HEALS) model, proposing that psychedelics reverse the typical left-hemisphere dominance in brain function, leading to right-hemisphere predominance during psychedelic experiences. Reviewing neuroimaging, lesion, and binocular rivalry studies, the article finds evidence of increased right-hemisphere activity and metabolic shifts under psychedelics, which correspond with cognitive and emotional changes such as broadened attention, enhanced creativity, emotional empathy, and altered language processing. The HEALS model situates these effects within a broader context of altered states of consciousness (ASCs), including meditation and trance, which also show right-hemisphere predominance. The article highlights limitations due to the exploratory nature of the hypothesis and calls for future research using hemisphere-specific interventions to test the model's predictions.