When people use a psychedelic called dimethyltryptamine (DMT), they experience a temporary loss of their sense of self. DMT interacts with a frequency of brain activity associated with self-referential processes (alpha waves), but it's unclear how this activity relates to self-awareness. Christopher Timmerman, at University College London, and Marco Aqil, currently at the University of Miami, are among researchers who used DMT as a tool to explore the relationship between alpha waves and self-awareness.
As reported in their JNeurosci paper, the researchers discovered that DMT interacts with alpha waves in a way that is associated with stronger ratings of loss of the sense of self, sometimes termed ego death. These activity changes were related to what is termed "criticality." Elaborates Timmerman, "The way the brain operates between chaos and order allows for normal brain function. Criticality refers to a brain state balanced between chaos and order that helps us predict things about the environment, the way we change or adapt to it, and our self-awareness."
Furthermore, the researchers found that this shift away from criticality was a dampening or quieting of alpha waves. Describing what this might mean, says Aqil, "We rely on past narratives and future predictions to have a coherent sense of self. In a DMT experience, people do not have a stream of consciousness over a period of time—everything takes place in the present moment. This shift in criticality signatures in the alpha frequency [during a DMT experience likely reveals how] the time-extended component of the sense of self is weakened."
Both Timmerman and Aqil emphasize their work supports the idea that psychedelics may be a powerful tool for unraveling the neurological basis of human consciousness.
