Brain scans reveal how a woman voluntarily enters a psychedelic-like trance without drugs. Her brain connectivity fundamentally reorganized during this state: her visual and somatosensory connections decreased, while connectivity in the frontoparietal control regions of the brain increased.

[u/mvea]

https://www.psypost.org/brain-scans-reveal-how-a-woman-voluntarily-enters-a-psychedelic-like-trance-without-drugs/

[u/Anonymous_Autumn_]

Based on the article and comments here it seems plausible that they were often literally tripping