Summary: A recent study used the psychedelic dimethyltryptamine (DMT) as a controlled scientific probe to examine how psychedelics change brain dynamics and disrupt the sense of self. The researchers found that DMT suppresses alpha-band activity and pushes brain activity away from a balanced, near-critical state — a balance thought to support coherent, time-extended self-awareness. These changes in alpha rhythms correlated with stronger reports of ego dissolution, suggesting psychedelics can reveal neural mechanisms that underlie consciousness and selfhood.
Using DMT in a laboratory setting, the team measured how the drug affects oscillatory activity in frequency bands tied to self-referential processing. Their findings point to a distinct pattern: a notable quieting of alpha waves together with an increase in neural entropy and a decrease in complexity, consistent with a shift away from criticality. This pattern correlates with subjective experiences where participants describe a loss of the continuous internal narrative that usually defines the self.
Key Facts
- Alpha-wave suppression: DMT produces a pronounced reduction in alpha-band power, a change that aligns with stronger reports of ego dissolution.
- Shift from criticality: The drug moves neural dynamics away from the brain’s typical balance between order and chaos, weakening the continuity of self-related thought over time.
- Research utility: Psychedelics like DMT can serve as powerful experimental tools to probe how the brain constructs self-awareness and organizes conscious experience.
Source: SfN
Dimethyltryptamine (DMT) is known for inducing intense, short-lived alterations in perception, often including transient loss of self or “ego dissolution.” Alpha-frequency oscillations have long been linked to self-referential processing and mind-wandering. The new study, led by Christopher Timmerman (University College London) and Marco Aqil (University of Miami), used controlled DMT administration alongside electrophysiological measures to clarify how changes in alpha activity relate to self-experience.
Published in the Journal of Neuroscience, the study shows that DMT reduces alpha-band activity and alters adjacent frequencies in a way that corresponds with participants’ introspective ratings of self-dissolution. The authors interpret these changes through the lens of criticality: a regime in which neural systems balance between order and disorder, optimizing responsiveness, prediction, and adaptive behavior. Under DMT, the brain’s dynamics shifted toward a subcritical regime, reducing the temporal continuity crucial for an extended sense of self.
Timmerman explains, “Normal cognition appears to rely on a balance between chaotic and ordered dynamics. Criticality captures that balance and supports our ability to predict the environment, adapt our behavior, and sustain a continuous sense of self over time.” Aqil adds, “Our sense of personal continuity depends on a stream of thoughts that link past memories and future expectations. During DMT experiences, that stream fragments — everything unfolds in the immediate present — and the neural markers of temporal continuity in the alpha band weaken.”
The study also applied newer measures of neural function, including an index of functional excitatory–inhibitory balance, finding that DMT-induced changes point toward subcritical network states. This combination of reduced alpha power, higher entropy, lower complexity, and altered excitatory–inhibitory metrics provides a coherent picture of how psychedelics temporarily reshape the brain’s operating regime and subjective sense of self.
Both primary investigators emphasize that their results support the use of psychedelics as experimental tools in consciousness science. By transiently disrupting canonical patterns of neural activity, these compounds allow researchers to link specific oscillatory signatures to aspects of subjective experience — in this case, the breakdown of temporal continuity and self-related narrative during ego dissolution.
COI Statement
One author is a shareholder of Aspect Neuroprofiles BV, a company that develops physiology-informed prognostic measures for neurodevelopmental disorders. All other authors declare no competing financial interests.
Key Questions Answered:
A: DMT suppresses alpha-band oscillations and shifts neural activity away from its usual near-critical balance. This suppression correlates with stronger subjective reports of ego dissolution and a disrupted continuity of self-related thought.
A: Criticality refers to a neural operating point between order and chaos. At or near criticality, brain networks optimally balance responsiveness and stability, supporting prediction, adaptation, and the temporal continuity that underlies a coherent sense of self.
A: DMT reliably and rapidly alters self-referential processing, allowing researchers to observe how changes in oscillatory dynamics—especially in the alpha range—impact the construction and maintenance of self-awareness.
Editorial Notes:
- This article was edited by a Neuroscience News editor.
- The full journal paper was reviewed during editing.
- Additional context was provided by editorial staff to clarify methods and implications.
About this psychopharmacology and consciousness research news
Author: SfN Media
Source: SfN
Contact: SfN Media – SfN
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Original Research: Closed access. “DMT-Induced Shifts in Criticality Correlate with Self-Dissolution” by Christopher Timmerman et al., Journal of Neuroscience.
Abstract
DMT-Induced Shifts in Criticality Correlate with Self-Dissolution
Psychedelic compounds profoundly change subjective experience and the brain’s dynamical patterns. Oscillatory activity often reflects near-critical dynamics relevant for healthy neural function. It has been proposed that shifts in proximity to criticality can explain both the experiential and neurophysiological effects of psychedelics.
This study examines how DMT affects the criticality of brain oscillations and how those shifts relate to subjective experience in human participants. The results indicate that DMT displaces dynamics away from criticality in the alpha band and adjacent frequencies, with accompanying increases in entropy and reductions in complexity.
Crucially, shifts in criticality observed in alpha and theta bands correlate with participants’ intensity ratings of self-dissolution, a central feature of psychedelic experience. Using a metric for functional excitatory–inhibitory ratio, the authors find that DMT moves oscillatory dynamics toward subcritical regimes.
These findings have important implications for understanding psychedelic mechanisms in the human brain and provide new insight into the neural basis of altered states of consciousness.