The neurobiology of altered states of consciousness induced by drumming and other rhythmic sound patterns.

Abstract

Humans have long sought to alter their mental states through various cultural practices, with rhythmic sounds emerging as a prominent and enduring method. However, altered states of consciousness induced by rhythmic auditory stimulation have not been comprehensively addressed in academic research, and the associated cognitive and neural underpinnings remain enigmatic. This narrative review synthesizes the behavioral, cognitive, and neural correlates underlying nonordinary experiences elicited by rhythmic sounds. The evidence gathered aligns with the notion that being exposed to these sounds facilitates a state of absorption and relaxation. The findings on the neural activity were diverse, reflecting the use of various methodologies in the reviewed studies. We discussed that altered states induced by rhythmic sounds may be explained by a mechanism involving the entrainment of thalamocortical pathways to low-frequency activity-a physiological state that also characterizes psychotic and psychedelic experiences. This proposal integrates insights from diverse findings, which reflect the variability in methodologies used to address these phenomena.