DMT-induced shifts in criticality correlate with ego-dissolution

The psychedelic DMT shifts brain oscillations away from criticality—a state thought to support healthy brain function—in alpha and adjacent frequency bands, moving toward subcritical regimes. Entropy increases while complexity decreases during this shift. The magnitude of the criticality shift in alpha and theta bands correlates with the intensity of ego-dissolution, a core feature of the psychedelic experience. These results suggest that altered proximity to critical brain dynamics may underlie the neurological and subjective effects of psychedelics, with implications for understanding altered states of consciousness.

Study at a glance

Abstract

ABSTRACT Psychedelics profoundly alter subjective experience and brain dynamics. Brain oscillations express signatures of near-critical dynamics, relevant for healthy function. Alterations in the proximity to criticality have been suggested to underlie the experiential and neurological effects of psychedelics. Here, we investigate the effects of a psychedelic substance (DMT) on the criticality of brain oscillations, and in relation to subjective experience. We find that DMT shifts the dynamics of brain oscillations away from criticality in alpha and adjacent frequency bands. In this context, entropy is increased while complexity is reduced. We find that the criticality shifts observed in alpha and theta bands correlate with the intensity ratings of ego-dissolution, a hallmark of psychedelic experience. Finally, using a recently developed metric, the functional excitatory-inhibitory ratio, we find that the DMT-induced criticality shift in brain oscillations is towards subcritical regimes. These findings have major implications for the understanding of psychedelic mechanisms of action in the human brain and for the neurological basis of altered states of consciousness.