A new study has found that a psychedelic formulation inspired by ayahuasca can significantly alter how the brain processes faces—especially one’s own. The research shows that the compound changes both early visual perception and later self-referential processing, effectively weakening the brain’s usual distinction between self and others. These findings, published in the journal NeuroImage, could help explain why psychedelics often produce feelings of ego dissolution and connectedness, and may shed light on their therapeutic potential for mental health conditions involving rigid self-focus.
Ayahuasca is a traditional psychoactive brew from the Amazon, typically made by combining a DMT-containing plant with another that inhibits the breakdown of DMT in the body. DMT, short for N,N-dimethyltryptamine, is a powerful psychedelic compound that, when taken on its own, is rapidly broken down by enzymes in the gut. The other ingredient, usually a vine containing harmine or other beta-carbolines, blocks this breakdown and allows the DMT to take effect. Together, these two substances produce an intense psychedelic experience characterized by vivid visuals, altered perception of self, and emotional insights.
The researchers behind the new study set out to investigate how this combination of substances influences one specific domain of perception: how we recognize faces and distinguish between ourselves and others. Previous research has shown that psychedelics affect visual perception and the brain’s default mode network, which is associated with self-referential thought. However, there has been little exploration of how psychedelics affect face recognition and the brain’s response to familiar and unfamiliar faces.
“We were fascinated by how psychedelics like DMT alter the sense of self and blur boundaries between self and others,” said study author Dila Suay, a postdoctoral researcher at the IMT School for Advanced Studies and the University of Zurich.
“These effects are often described subjectively, but less is known about their neural basis, especially in relation to face perception, which plays a central role in social identity. This study aimed to investigate whether a DMT/harmine formulation could measurably affect how the brain differentiates between self and other faces.”
To examine this, the researchers conducted a placebo-controlled experiment involving thirty healthy male volunteers. Each participant took part in three experimental sessions. In one session, they received a placebo; in another, they were given only harmine; and in the third, they received both DMT and harmine. The DMT was administered through a nasal spray, while harmine was taken in tablet form. Each session was separated by a two-week washout period.
During each session, participants completed a face recognition task while wearing an EEG cap that recorded electrical activity in the brain. The task involved viewing a series of images on a screen, including pictures of their own face, faces of well-known celebrities they recognized, and completely unfamiliar faces. Occasionally, scrambled images were included as targets to ensure participants stayed focused.
The EEG allowed the researchers to track brain responses to the faces at different time points, focusing on three specific brain signals. The P1 signal appears very early, around 100 milliseconds after seeing a stimulus, and is associated with basic visual processing. The N170 signal, which occurs slightly later, is related to the brain’s ability to recognize faces as faces. The P300 signal appears later still, and reflects deeper cognitive processing, such as distinguishing between familiar and unfamiliar information and allocating attention to self-relevant stimuli.
The results showed that the combination of DMT and harmine altered face processing at all three stages. Across all face types—self, familiar, and unknown—the DMT/harmine mixture enhanced the P1 response. This suggests that the drug increased early visual responsiveness, making the brain more reactive to incoming visual information. At the same time, it reduced the N170 response, which points to a disruption in the brain’s ability to structurally process faces. In other words, while participants’ visual systems were more sensitive overall, they became less efficient at recognizing faces as coherent, structured identities.
But the most interesting effects appeared in the P300 signal. Under placebo and harmine-only conditions, the brain showed a strong distinction between self and other faces in this later stage of processing. The self-face triggered a larger P300 response, reflecting its special significance and the brain’s tendency to give it more attention.
However, under the influence of DMT/harmine, this difference shrank. The P300 response to the self-face became more similar to the response to familiar and unfamiliar faces. This suggests that the brain was no longer treating the self as uniquely special. The neural boundary between self and others had become less defined.
“We were surprised by how consistent the neural flattening was across participants and face types,” Suay told PsyPost. “Even early visual markers like the N170, which typically reflect facial recognition, were significantly dampened. It suggests that DMT not only alters conscious experience but also disrupts fundamental stages of face perception, challenging how we define the “self” at the perceptual level.”
Importantly, the brain’s response to familiar faces, such as celebrities, remained relatively stable across all conditions. This indicates that the drug did not simply disrupt all face processing indiscriminately. Instead, it appeared to target self-referential processing in a selective way, diminishing the sense of distinction between self and other without erasing recognition of socially meaningful faces.
The researchers also found that these changes in brain activity were related to participants’ subjective experiences. Reductions in the N170 and P300 signals under DMT/harmine were associated with stronger reports of ego dissolution, spiritual experiences, and vivid imagery. This suggests that the neural blurring of self-other boundaries may contribute to the felt experience of losing one’s sense of a separate self, a hallmark of many psychedelic experiences.
These findings help explain how psychedelics can produce profound changes in the sense of self. The attenuation of the P300 response to one’s own face may reflect a reduction in the brain’s usual tendency to prioritize self-relevant information. This could underlie the feeling of being less self-centered or more connected to others. At the same time, the fact that familiar faces were still processed normally suggests that the brain retains an anchor to social reality, even as the boundaries between self and other begin to shift.
“Our results suggest that under the influence of this ayahuasca-inspired formulation, the brain becomes less distinct in how it processes one’s own face compared to familiar or unfamiliar faces,” Suay explained. “This supports the idea that psychedelics can dissolve rigid self-other boundaries, which may underlie some of their therapeutic and empathic effects. It also adds to a growing understanding of how identity and self-perception are dynamically constructed in the brain.”
This dynamic may be part of what makes psychedelics therapeutically promising for conditions like depression or social anxiety, where people can become overly fixated on negative self-referential thoughts. By loosening the brain’s grip on the self as a distinct and fixed entity, psychedelics may create space for new perspectives and emotional flexibility.
As with all research, the study has limitations. It only included healthy male participants. The effects observed were tied to a specific dose and route of administration, so they might not apply to other psychedelic compounds or delivery methods. Also, while EEG offers detailed timing of brain activity, it lacks spatial precision, making it difficult to pinpoint exactly which brain areas are responsible for the observed effects.
“The effects we observed may differ in clinical populations or across repeated exposures. Additionally, although EEG allowed us to track real-time changes in brain activity with high precision, it doesn’t provide detailed spatial information about which brain areas are involved. Future studies combining EEG with techniques like fMRI or source localization could deepen our understanding of where and how these alterations occur in the brain.”
Another important consideration is that ego dissolution is not always experienced as positive. In this study, reductions in the brain’s differentiation between self and others were more strongly associated with feelings of anxious disorientation than with blissful unity. This highlights that psychedelics can produce a range of psychological experiences, and not all of them are therapeutic. Understanding what determines whether ego dissolution is beneficial or distressing is an important goal for future research.
The researchers suggest that future studies should explore how these brain responses change over time and whether the effects on self-referential processing persist after the psychedelic experience ends. They also propose looking at connectivity patterns in the brain to see how information flows between regions during these altered states.
“We’re currently exploring more nuanced analyses, including connectivity patterns, to better understand how self-related processing is reconfigured under psychedelics,” Suay said. “In the long run, we hope to bridge this kind of basic neuroscience with clinical applications, especially in therapies targeting self-related disorders like depression, trauma or identity disturbances.”
“I think what’s most compelling is that we’re starting to see how subjective changes in identity during psychedelic experiences can be objectively tracked in the brain. That opens new doors for both science and therapy, especially for conditions where people feel disconnected from themselves or others.”
The study, “Ayahuasca-inspired DMT/HAR formulation reduces brain differentiation between self and other faces,” was authored by Dila Suay, Helena D. Aicher, Michael Kometer, Michael J. Mueller, Luzia Caflisch, Alexandra Hempe, Camilla P. Steinhart, Claudius Elsner, Ilhui A. Wicki, Jovin Müller, Daniel Meling, Dario A. Dornbierer, Milan Scheidegger, and Davide Bottari.
