Exploring the latest research on what altered-states reveal about reality
There are few questions more likely to make neuroscience suddenly resemble philosophy than this one: what should we make of a person who takes a psychedelic drug, enters what appears to be another world, and encounters an intelligent being who seems entirely independent of them?
The temptation is to force the experience into one of two familiar stories. Either the entity is a hallucination, an elaborate artefact generated by a chemically disturbed brain, or the drug has somehow opened access to a reality ordinarily concealed from human perception.
Christopher Timmermann’s work is interesting precisely because it resists this binary. A neuroscientist and psychologist who has conducted some of the first human brain-imaging studies of the psychedelic compound DMT, Timmermann has spent much of the past decade studying what happens when familiar structures of experience become radically unstable: when the boundary between self and world loosens, when space seems to reorganise itself, when apparently autonomous presences emerge, and when consciousness appears, at its furthest limits, to persist with very little recognisable content at all.
Timmerman’s work brings many of these strands together under the deliberately provocative themes of psychedelics, entities and consciousness; Its questions range from whether DMT entities might be considered “real”, to what 5-MeO-DMT and advanced meditation might reveal about experiences of non-duality and apparently “pure” consciousness. Yet his research is ultimately less an attempt to prove what psychedelic visions are, than an investigation into something more consequential: how human beings construct a world, a self, and the other minds within it.
Psychonaut Psychology
Timmermann’s route into this territory began with psychology rather than psychedelic culture. He completed a BSc in Psychology at the Pontificia Universidad Católica de Chile, followed by an MSc in Neuroscience at the University of Bologna, before completing a PhD in Neuropsychopharmacology at Imperial College London. At Imperial he subsequently led its DMT research group, helping pioneer the use of human neuroimaging to investigate short-acting psychedelic states. He is now co-director of the UCL Centre for Consciousness Research and remains an honorary research fellow at Imperial College London’s Department of Brain Sciences.
That trajectory matters because it helps explain the unusual character of his research. Timmermann is not simply studying whether psychedelic drugs alter particular neurotransmitters or brain networks. His work sits at an intersection of neuroscience, psychology, phenomenology, psychiatry and philosophy of mind. Alongside psychedelics, he has increasingly studied meditation and other non-ordinary states as methods for perturbing the normally stable organisation of consciousness.
He has also helped establish the Chile-based ECOH Foundation, whose work brings research and education about consciousness into dialogue with meditation, psychedelic practice and Latin American cultural contexts. This broader interest in the social and cultural interpretation of altered states is important. A psychedelic experience does not arrive in an interpretive vacuum. People encounter it carrying expectations about brains, spirits, trauma, religion, medicine and reality itself. Those expectations may subsequently be transformed by what occurs.
Timmermann has described himself in public discussion as a “metaphysical agnostic” and a “pragmatic physicalist”. It is a revealing formulation. Neuroscience provides the practical tools with which he investigates consciousness, but he does not treat those tools as automatically settling the larger metaphysical question of what consciousness ultimately is.
This is not intellectual fence-sitting so much as an acknowledgement of levels of explanation. The fact that an experience has measurable neural correlates tells us something important about its biological conditions. It does not necessarily tell us everything about what the experience means, nor does it independently adjudicate every claim someone might subsequently make about reality.
DMT: Spirit Science
N,N-Dimethyltryptamine, usually abbreviated to DMT, is particularly attractive to consciousness researchers because it produces extraordinarily intense effects over a remarkably short period when administered intravenously.
Instead of examining relatively slow changes unfolding over several hours, researchers can observe a rapid transition from ordinary waking consciousness into a profoundly altered state and back again. In experimental terms, it is almost a controlled storm: consciousness changes dramatically while researchers collect continuous physiological, neural and subjective data.
Timmermann’s early EEG work provided an important glimpse of what happens during that transition. In a 2019 study involving 13 participants receiving intravenous DMT, researchers found pronounced reductions in alpha and beta oscillatory power alongside increases in measures of neural signal diversity. Changes in slower delta and theta activity were associated with aspects of the peak subjective experience, particularly its intense eyes-closed visual qualities.
A larger 2023 study combined EEG with functional MRI in 20 healthy participants. Under DMT, the brain’s familiar large-scale networks became less internally segregated. Global functional connectivity increased, distinctions between normally separate networks weakened, and the brain’s usual hierarchical organisation was compressed. Changes were particularly prominent in higher-order association regions associated with the serotonin 2A receptor, a major target of classical psychedelic drugs.
This is sometimes compressed in popular psychedelic language into the claim that DMT makes the brain “more connected” or “more entropic”. But both descriptions can become misleading if taken too literally. Entropy in this literature does not just mean chaos, nor does greater signal diversity mean that the brain is functioning at a “higher level”. It refers to particular mathematical properties of brain activity becoming less predictable or less constrained.
Different measures can tell different stories. Indeed, later work led by Timmermann examining neural criticality found that DMT could simultaneously increase some measures of entropy while reducing complexity according to other metrics and shifting oscillatory dynamics away from criticality. The lesson is less glamorous but considerably more useful: there is no single scientific dial labelled “consciousness level” that psychedelics simply turn up. What DMT appears to do is reorganise the constraints under which conscious experience is constructed, and this is where entities enter.
A Strange Population
Reports of seemingly autonomous beings are among the most conspicuous features of DMT culture. Users have described figures interpreted as spirits, aliens, teachers, guides, ancestors, gods, tricksters and intelligences of categories for which ordinary language has few convenient drawers. Their defining feature is often not simply visual complexity – it is agency.
People frequently report that the presence seems to possess its own intentions, knowledge or emotional attitude. It may observe them, communicate with them, inspect them, reassure them or behave in ways the experiencer did not consciously anticipate. The encounter therefore does not feel like deliberately imagining a character, it feels like meeting someone.
Large surveys have shown how psychologically powerful such episodes can be, although these surveys should not be mistaken for estimates of how frequently entities occur among all DMT users. One study specifically recruiting 2,561 people who had already experienced memorable entity encounters found that participants frequently described the figures as beings, guides, spirits, aliens or helpers and often attributed lasting personal or metaphysical significance to the encounter.
Timmermann’s more recent work asks a different and arguably more revealing question: how does the experience of an entity come into existence? A 2026 neurophenomenological study examined detailed reports from 23 people who had received 20mg of intravenous DMT while undergoing simultaneous EEG-fMRI. Rather than relying only on standard psychedelic questionnaires administered after the event, the researchers conducted detailed microphenomenological interviews intended to reconstruct the unfolding structure of experience. They identified 125 categories spanning sensation, space, embodiment, selfhood, sociality and other dimensions.
What emerged was a surprisingly orderly sequence beneath what may subjectively feel like pandemonium. Bodily alterations generally occurred early, and visual and auditory transformations developed next. A more organised, multi-sensory and three-dimensional experiential world gradually emerged, and perceived presences tended to appear only after this immersive world had been established. This finding subtly changes the entity question.
Rather than treating entities as isolated hallucinated objects suddenly inserted into consciousness, the study suggests that they may be higher-order products of an increasingly coherent alternative world-model. First the architecture of experience changes: space acquires depth, sensory modalities become integrated, and a world becomes available. Then something can appear to inhabit it.
The observation is intriguing because ordinary consciousness may work according to a related logic. A person does not merely receive raw sensory data and subsequently notice a human being standing across the room. The brain continuously constructs estimates of objects, spaces, causes, intentions and other minds. Under ordinary conditions this inferential work is so fluent that its construction remains largely invisible. DMT may expose the scaffolding.
Manufactured Minds
In a 2026 theoretical paper, Timmermann and colleagues developed this possibility further through a computational model of psychedelic entity encounters. The proposal draws on predictive processing and active inference, approaches in neuroscience which treat perception not as passive reception but as continual inference. The brain attempts to determine the hidden causes of incoming signals, and much of what is experienced as reality therefore depends upon the brain’s best working model of what is producing its sensory input.
Agency poses a special problem: the brain must distinguish events generated by oneself from events caused by something else. Under ordinary circumstances, mechanisms such as sensory attenuation help mark the predictable consequences of one’s own actions and thoughts as self-generated.
The theoretical model proposes that psychedelics may disrupt this discrimination while simultaneously generating extraordinarily rich, surprising and difficult-to-predict perceptual material. When internally generated experience becomes sufficiently complex while losing some of the signals that ordinarily identify it as self-produced, the brain may infer the most plausible cause available: another agent.
The resulting entity can therefore feel autonomous not merely because it looks unusual, but because its behaviour is experienced as exceeding the subject’s own predictions. Importantly, Timmermann and colleagues explicitly state that this model does not adjudicate the ontological status of psychedelic entities. It is a model of how the experience of autonomous presence could arise, not proof that every entity is imaginary, nor evidence that any entity exists independently of the experiencer. No new experimental data were generated for the paper itself; it is a theoretical synthesis intended to generate testable hypotheses, which is a key distinction.
Really Reality
Are DMT entities real? Science can answer this question only after defining what “real” is supposed to mean. As experiences, DMT entities are unquestionably real events. They occur in consciousness, have measurable biological correlates and may have lasting effects on behaviour, beliefs and wellbeing. To call something a hallucination does not render its psychological consequences fictional.
But the stronger claim, that the entity possesses an existence independent of the person experiencing it, requires a different kind of evidence. Neuroscience alone cannot logically prove that an externally existing entity is absent simply by identifying brain activity associated with seeing it. Looking at an ordinary tree also produces neural activity, neural correlation does not demonstrate that the tree exists only inside the brain.
Yet the reverse is equally important. The overwhelming subjective conviction that an entity is external does not demonstrate that it actually is. Humans routinely experience dreams, hallucinations, sensed presences and perceptual illusions as events that seem to originate beyond deliberate imagination.
The scientifically responsible position is therefore asymmetrical but open: a plausible neurocognitive account can explain how experiences of autonomous entities might arise without invoking externally existing beings. Claims that the entities independently inhabit another dimension, realm or level of reality would require additional evidence capable of distinguishing that hypothesis from an internally generated experience.
At present, such evidence has not been established by Timmermann’s work. This is where metaphysical agnosticism earns its keep. It allows the phenomenology to remain strange without allowing strangeness itself to become evidence.
Pure Possibility
If DMT overwhelms consciousness with elaborate worlds, 5-MeO-DMT presents almost the inverse experimental problem. 5-MeO-DMT is a related but phenomenologically distinctive psychedelic. At sufficiently intense doses, people sometimes report not more objects, images and narrative but less: disappearance of bodily identity, autobiographical selfhood, conceptual thought and even distinctions between subject and object. Could consciousness remain when almost everything consciousness is normally about disappears?
Timmermann and colleagues explored this question in a 2025 study examining 14 participants taking 5-MeO-DMT in naturalistic ceremonial settings in the Netherlands and Spain. Using EEG alongside detailed microphenomenological interviews, they described episodes of what they called “deconstructed consciousness”: states involving loss of narrative and embodied selfhood and extremely sparse phenomenal distinctions while wakefulness appeared to persist. The terminology is careful for good reason.
Calling such experiences “pure consciousness” may imply that researchers have discovered consciousness stripped of the brain, body or all mental content. The data establish nothing of the sort. Even “contentless” consciousness becomes conceptually slippery because the moment someone remembers timelessness, luminosity, unity or absence, something phenomenological appears to have been present.
Memory creates a further problem. Some participants displayed partial amnesia around the most intense periods. If a person reports that nothing was present, researchers have to distinguish between genuinely minimal experience and an experience that simply failed to enter retrievable memory.
Only around a third of participants showed the paper’s clearest form of deconstructed consciousness, and only during particular moments. This matters because psychedelic states are often discussed as if the drug simply produces one homogeneous condition. Timmermann’s work instead emphasises their temporality. A person can move through radically different structures of consciousness within minutes. The methodological problem becomes almost philosophical: how does science study an experience whose defining feature may be the disappearance of the faculties needed to describe it?
Methodological Meditation
This question has also brought Timmermann into dialogue with contemplative practice. Meditative traditions have spent centuries developing taxonomies of altered attention, selflessness, non-duality and forms of awareness described as minimally conceptual. Psychedelic neuroscience offers an unusual opportunity to compare these states without assuming in advance that they are identical.
A 2025 preprint involving an expert Mahāmudrā meditation practitioner examined this directly. The practitioner underwent non-dual meditation as well as placebo and two doses of 5-MeO-DMT while high-density EEG and detailed phenomenological measures were collected.
The comparison found some overlap between non-dual meditation and lower-dose 5-MeO-DMT, including reductions in narrative selfhood, conceptual labelling and ordinary temporal experience. Yet important differences remained. Meditation was characterised more strongly by clarity and non-duality, while psychedelic states could contain distinctive perceptual effects. At the higher 5-MeO-DMT dose, the participant experienced profound sensory disconnection and a “white light”-type state accompanied by a different electrophysiological pattern.
The authors tentatively propose that profound self-deconstruction might therefore be approached by more than one route. One could involve a subtractive reduction of conceptual and narrative processing, closer to some meditative states. Another might involve an overwhelming or saturating process in which ordinary distinctions collapse under radically altered neural dynamics.
It is an intriguing hypothesis, but also an excellent place for scientific restraint. This was a single-person case study and remained a preprint, not evidence that meditation and 5-MeO-DMT universally operate through two established neural pathways. What it does demonstrate is the sophistication of the question now being asked. “Do meditation and psychedelics both cause ego dissolution?” is comparatively crude. A better question is: which components of selfhood disappear, in what order, through what mechanisms, while which aspects of awareness remain?
Beyond Belief
There is another reason Timmermann’s cautious approach matters. Psychedelic experiences do not merely generate unusual perceptions, they can alter a person’s sense of what is plausible. In a 2021 study involving hundreds of participants, Timmermann and colleagues found that psychedelic use was associated prospectively with shifts away from hard materialist or physicalist positions and toward a cluster of non-physicalist beliefs encompassing ideas such as panpsychism and forms of dualism or idealism. Related changes were also observed in clinical psychedelic data.
That result is fascinating, although emphatically not evidence that psychedelics reveal non-physicalist metaphysics to be true / real. The authors themselves warn against that interpretation. Psychedelics can increase suggestibility, emotional intensity and the feeling of profundity or “noetic” certainty. Belief formation can also be shaped by expectations, interpersonal influence, cultural settings and the assumptions of therapists, researchers or communities surrounding an experience.
Timmermann’s related work on what he and colleagues call psychedelic apprenticeship therefore argues for careful mediation of psychedelic insights. Experiences may produce therapeutically important discoveries, but the feeling that something is unquestionably true does not guarantee its factual accuracy. A revelation can be psychologically transformative without functioning as reliable evidence about cosmology.
This may be one of the most important lessons to emerge from contemporary psychedelic research. Modern culture frequently places hallucination and revelation at opposite ends of an epistemic spectrum. One is dismissed as meaningless brain noise; the other is elevated as access to hidden truth. The evidence suggests a more interesting middle territory. Experiences can be constructed and meaningful. They can be neurologically mediated and existentially consequential. They can expose previously unnoticed psychological patterns while generating mistaken interpretations of them. And the conviction accompanying an insight is itself become something to investigate.
Significant Not Serious
This is why Timmermann’s increasing use of neurophenomenology is significant. Conventional neuroscience often reduces subjective experience to questionnaire scores: intensity seven out of ten, ego dissolution six, visual imagery nine. Neurophenomenological approaches instead attempt to reconstruct the fine-grained organisation and temporal development of experience and then relate it to measurements from the brain, body and environment.
If researchers want to understand consciousness, simply knowing that “ego dissolution occurred” is insufficient. Did the body’s boundaries disappear first? Did autobiographical identity vanish while spatial perspective remained? Was there still a centre from which perception seemed to occur? Did a world remain without an observer? Did an entity appear before or after three-dimensional space developed? Such distinctions can transform apparently mystical anecdotes into structured research questions without stripping them of their phenomenological complexity.
They also challenge one of neuroscience’s habitual asymmetries. Third-person measurements are often treated as hard data while first-person experience is considered unreliable noise. Yet consciousness is unusual because the phenomenon being studied is, by definition, accessible through experience. Brain measurements without sufficiently precise phenomenology can therefore become exquisitely detailed measurements of something researchers have poorly characterised. Timmermann’s approach attempts to make the two constrain one another.
The deepest contribution of this research may not concern DMT at all. Psychedelics are scientifically useful partly because they exaggerate processes that ordinary consciousness normally hides. The everyday world feels simply given. There appears to be a stable body located inside continuous three-dimensional space, surrounded by objects and other autonomous minds. Attention moves through this environment while a relatively persistent “I” seems to experience it.
Yet Timmermann’s experiments show that these supposedly elementary features can separate. Spatial depth can change, self-location can weaken, sensory modalities can cease to cohere in their usual way. The distinction between self-generated and externally generated events can become unstable. A world can appear before an inhabitant appears within it, and an apparently autonomous other can emerge from that world. Under still different conditions, the distinction between subject and object can almost disappear altogether.
Consciousness begins to look less like a screen onto which perceptions are projected and more like an ongoing act of organisation. This does not mean everyday reality is therefore “just a hallucination”, another phrase whose popularity has outpaced its precision. Ordinary perception is tightly constrained by sensory information, bodily action and a shared environment. Psychedelic perception demonstrates not that reality is unreal, but that our experience of reality depends upon inferential architectures whose contribution is normally difficult to see.
DMT turns some of those architectures inside out. The entity encounter is particularly revealing in this respect. Its scientific importance may have little to do with whether machine elves, spirits or interdimensional intelligences exist. It may instead lie in showing how profoundly the mind is equipped to construct other minds: not merely faces and bodies, but centres of agency, intention and relationship.
Likewise, 5-MeO-DMT’s importance may not rest on demonstrating a mystical substrate of “pure consciousness”. Its value may lie in allowing researchers to dismantle components of ordinary selfhood and ask which elements of consciousness can disappear while others persist. And meditation offers a third perturbation, one produced not predominantly through pharmacology but through cultivated changes in attention, conceptualisation and self-models. Taken together, these approaches turn altered states into experimental tools for reverse-engineering ordinary consciousness.
Productive Uncertainty
There is something refreshingly unresolved about Timmermann’s work. Psychedelic science has inherited two opposing risks. The first is reductionism: treating unusual experiences as nothing more than receptor activation and neural noise. The second is metaphysical inflation: treating the intensity and apparent authority of psychedelic experience as evidence that whatever it presents must correspond to some hidden level of reality.
Timmermann’s research occupies the more difficult territory between them: brain, culture, expectation, phenomenology, and interpretation. And none individually exhausts the phenomenon. Perhaps the most intellectually useful response to a DMT entity, then, is neither immediate belief nor immediate dismissal. It is to notice how extraordinary the underlying event already is before adding a supernatural explanation: a human nervous system can generate an immersive world, locate a self within it, populate it with another apparent consciousness and produce the overwhelming conviction of encountering something beyond itself.
That alone poses a considerable mystery. And if consciousness research eventually discovers that the story is stranger still, the route to that discovery will require exactly the distinction Timmermann’s work repeatedly tries to preserve: between what an experience feels like, how an experience is generated, what an experience means, and what it demonstrates about reality. Those are four different questions. The psychedelic state has a habit of making them feel like one.
