The loosened mind and what it reports

Your seer does not strain. That is the rule the novel is built on, and it is a rule about what a person does not do: she keeps her eyes open, she does not reach for the shape, she does not check whether what she is seeing is there. The strainers calcify. They grip, and the grip is what blinds them. The obvious reading is a mystical one, and this paper is not going to pretend that the mystical reading has no support, because behind it stands an old and unusually consistent literature. A Via Negativa approaches God by negation and speaks only in terms of what may not be said about God [1]. A manual of unknowing was written in the latter half of the fourteenth century [2]. A Buddhist analysis treats upādāna, the Sanskrit and Pāli word for clinging, as one of two primary causes of dukkha [3]. But there is a second reading now, and it is written in the vocabulary of the laboratory. On that reading the seer is not seeing through a hole in her skull. She is running a monitoring system below the threshold of her own control, and the loosening of that system is exactly what makes the vividness go up. The question this paper takes seriously is narrow. It is not whether consciousness can perceive something outside itself. It is whether the inverse relation the novel needs — less measuring, more seeing — describes a relation between control and vividness, or a relation between control and truth. Those are not the same claim, and the difference between them is where the honest answer lives.

The network that runs when nothing is asked

The place to start is a network that was discovered by subtraction. In neuroscience the default mode network, also known as the medial frontoparietal network, is a large-scale brain network composed primarily of the medial prefrontal cortex, the posterior cingulate cortex, the precuneus and the angular gyrus [4]. Raichle coined the term default mode in 2001 to describe resting state brain function [4]. The name is a piece of accounting: the network was originally noticed to be deactivated in certain goal-oriented tasks and was therefore sometimes called the task-negative network [4]. What it does when nothing is asked of it is the interesting part. The literature describes it as creating a coherent internal narrative central to the construction of a sense of self [4]. That sentence is doing more work than it first appears. A network that builds a narrative is a network that is always telling its owner who the owner is, what the owner was doing, and what the owner intends to do next. It is a machine for producing a continuous answer to the question of who is here.

Default mode network-WRNMMC. Photo: John Graner, Neuroimaging Department, National Intrepid Center of Excellence, Walter Reed National Military Medical Center, 8901 Wisconsin Avenue, Bethesda, MD 20889, USA. / Wikimedia Commons. The default mode network in orange over a structural MRI, in sagittal and axial views. Source

Control, in the same literature, has a name too. Executive functions include basic cognitive processes such as attentional control, cognitive inhibition, inhibitory control, working memory and cognitive flexibility [5]. These are the processes by which a person holds a target, suppresses the competing response, and keeps going when the interesting thing is not the current thing. The novel’s seer is defined by their absence, and the imaging literature locates their presence in the same brain that runs a narrative self. This is worth stating plainly before any drug enters the picture, because it means the two halves of the paper are about one structure seen from two ends: a controller, and the story the controller keeps about itself.

The framework that ties them together arrived later and is now the common currency of the field. Predictive coding is one member of a wider set of theories that follow the Bayesian brain hypothesis [6]. Under this account the brain is not a receiver that is occasionally wrong. It generates predictions about what is coming and corrects them against incoming signal, and the correction signal is the only thing about the world the brain ever actually receives. Predictive coding inverts the conventional view of perception as a mostly bottom-up process, suggesting that it is largely constrained by prior predictions, where signals from the external world only shape perception to the extent that they are propagated up the cortical hierarchy [6]. The formal version says much the same thing. The free energy principle holds that the dynamics of physical systems minimise surprisal, or equivalently free energy [7], and under it systems pursue paths of least surprise, or equivalently minimise the difference between model predictions and their sense and associated perception [7].

If that is the machinery, then the question of how hard the controller presses is not a metaphor. It is a question about a gain. Optimising the precision parameters corresponds to optimising the gain of prediction errors [7]. A system that weighs its predictions heavily is a system that changes its mind slowly. A system that weighs them lightly is a system that is unusually open to whatever arrives next. Every claim in this paper about effort and openness is a claim about that dial.

One distinction has to be drawn before the argument starts, because the novel’s seer does not stop controlling everything. She controls where she looks and when she opens her eyes; what she gives up is the second stage, the judgement of what she has got. The literature on metacognition draws exactly this line between monitoring, which means making judgments about the strength of one’s memories, and control, which means using those judgments to guide behaviour [8]. A seer who keeps the first and drops the second is not uncontrolled. She is unverified. That is a smaller claim than the novel may need, and it is the one the rest of this paper tests.

What the classic psychedelics do to it

The pharmacology is the cleanest experiment we have on that dial, because the dial can be turned by a molecule rather than by an argument. One study on the effects of LSD demonstrated that the drug desynchronizes brain activity within the default mode network, so that the activity of the brain regions that constitute the network becomes less correlated [4]. The same direction of effect appears in the wider neuroimaging summary, which reports that LSD decreases oscillatory power within the default mode network, reduces the efficacy of thalamo-cortical information filtering with the sensory overload that follows from it, and flattens the hierarchical organization of large-brain activity [9]. Three systems at once: the narrative self, the filter that decides what gets through, and the hierarchy that sets the ranking of one signal against another.

LSD 2D, 3D. Photo: Acdx / Wikimedia Commons. The two dimensional structural diagram of LSD beside a space filling model of it. Source

Connectivity tells the same story in a laboratory instrument rather than a thought experiment. One of the most robust findings in the field is a psychedelic-induced acute decrease in functional connectivity within the default mode network [10]. That statement comes from a pharmaco-fMRI study in rats, titled for the finding that psilocybin-induced default mode network hypoconnectivity is blunted in alcohol-dependent rats [10], and the honest use of it is as a replication of the direction in a species where dose and timing can be held still, not as a claim about human mystical experience.

What the drug does not do is repair the narrative. It loosens it. Psychedelic experiences feature alterations in normal perception such as visual distortions and a subjective loss of self-identity, sometimes interpreted as mystical experiences [11], and the phenomenon of ego dissolution is often described as a key feature of the psychedelic experience [11]. That is the word the paper’s title borrows. Ego dissolution is not an absence of experience. It is a specific report, and because it is a report it can be measured. The Ego-Dissolution Inventory is an eight-item self-completed questionnaire [12], and an exploratory factor analysis found that all eight items loaded onto a single factor, which is the psychometric way of saying that the thing being measured is one thing rather than eight [12]. A single factor is good news for the instrument and complicated news for the interpretation, because it means the state does not come in flavours.

The chemistry of the loosened state is usually framed as entropy. The entropic brain hypothesis proposes that brain entropy, the degree of uncertainty in the distribution of brain states, is elevated during the psychedelic state, as well as in other states characterised by an expanded breadth of phenomenal consciousness [13]. The same review names its own difficulties, and they belong in this paper rather than in a footnote: entropy alterations are not specific to psychedelics or other states of heightened phenomenal richness, and substantial questions remain about the validity of entropy-based biomarkers of the psychedelic state [13]. An index that goes up whenever consciousness gets wide is measuring width, not truth. That is the deflationary problem in its purest form, and the review that names it does so itself, from inside the field.

DMT is worth one sentence of its own because the popular version of this material carries a claim the drug does not support on its own. Dimethyltryptamine is a serotonergic hallucinogen of the tryptamine family that occurs naturally in many plants and animals, and it is not orally active on its own but given by parenteral administration such as smoking or injection [14]. Smoking and intravenous injection of DMT are described as having extremely intense but very-short-lived effects, whereas intramuscular injection and particularly oral administration with an MAOI have less intense but longer-lasting effects [14]. A compound whose most intense form lasts minutes is a poor instrument for deciding whether anything was received.

The vocabulary the seer’s tradition uses deserves the same care. Mysticism is popularly used as a synonym for mystical experience, an ecstatic unitive experience of becoming one with God, the Absolute or all that exists [15], and the mystic experience can be defined as the mystic’s purported access to realities or states of affairs of a kind not accessible by way of ordinary sense-perception structured by mental conceptions, somatosensory modalities, or standard introspection [15]. That definition is the honest core of the novel’s premise and it is also its weakest joint, because access is defined as the thing that cannot be checked. Note what the definition does not say: it does not say the content is wrong. It says the route is private, and that is exactly the condition under which source monitoring cannot run.

The chemistry of loosened belief

The model that ties the pharmacology to the phenomenology is REBUS, and it is the strongest version of the novel’s rule that anyone has written down. The REBUS model proposes that the entropic brain state induced by psychedelics corresponds to a relaxation in the precision-weighting of neuronally encoded predictive models [16]. Read that sentence carefully, because it is the whole thesis. Precision weighting is how much weight a brain gives to what it already believes. Relax it, and the brain keeps believing everything it believed, but with less authority. It does not stop having priors. It stops insisting.

Analytical balance - Thomas Edison National Historical Park - West Orange, New Jersey. Photo: Jeff Keyzer from Austin, TX, USA / Wikimedia Commons. A two pan analytical balance with a graduated beam, its two pans inside a glazed case. Source

The consequences follow directly. Within the transient drug-induced state of enhanced plasticity, REBUS proposes a reduction in the felt confidence associated with maladaptive beliefs and assumptions that are ordinarily encoded with excessive precision-weighting [16]. Sensitisation of the brain to new evidence through the relaxation of high-level priors may sometimes be beneficial in itself, independent of the valence of the new evidence, since desirable evidence is typically overweighted and undesirable evidence underweighted in healthy people [16]. The administration of a psychedelic is associated with self-reported increases in positive self-related beliefs [16]. So the model predicts a specific, testable asymmetry: less grip on the pessimistic story, more grip on the hopeful one, with the content of the new evidence held constant.

The authors are more careful than their critics usually allow. They report that evidence supporting a relationship between negative belief relaxation and revision and neurobiological markers of REBUS, or subsequent improvements in well-being, remains elusive [16]. In the same paper they present large associations between reduced negative self-belief confidence and neural entropy that they themselves call very preliminary evidence [16]. The first of those two sentences is the most important one in the primary literature for a paper like this, because it comes from the model’s own authors. The chain from molecule to loosened precision to revised belief to improved wellbeing is drawn in theory more completely than it has been measured, and the missing link is the one that would let an outside observer confirm the certainty of the person inside the state.

There is a second model in the same family that is about mind-reading rather than belief, and it matters more for this paper. A meta-analysis of fMRI studies of external source monitoring and reality monitoring investigates the discrimination between one external and another internal source of information [17]. Memory for the information and memory for the source are intrinsically connected, but the neural underpinnings for source-memory monitoring remain unclear [17]. Source monitoring is the brain’s answer to one question only: did this come from in here or from out there. It is not a question about vividness, and a report can be maximally vivid and completely unmonitored.

What the contemplative literature already said

The novel’s rule is not new, and the reason it is not new is that the contemplative traditions built their practices on exactly this mechanism before neuroscience had a word for it. Apophatic theology, also known as negative theology and the Via Negativa, is a form of theological thinking which attempts to approach God by negation, to speak only in terms of what may not be said about God [1]. The consequence of that method is the part that matters here: the Enneads of Plotinus, read as a spiritual or ascetic teaching device, lead to silence and the abandonment of all intellectual inquiry, leaving contemplation and unity [1]. The apophatic tradition is often, though not always, allied with the approach of mysticism, which aims at the perception of the divine reality beyond the realm of ordinary perception [1]. Read as instruction rather than as theology, it is a procedure for withdrawing the inspecting apparatus before the inspection is finished.

Cloister gardens and walkway. Photo: NancyHeise / Wikimedia Commons. A cloister walkway with pointed arches along one side, opening onto the garden. Source

The most explicit version is a fourteenth-century manual. The Cloud of Unknowing holds that God cannot be understood via reason or intellect but only through love, and it recommends cultivating two mental states, the cloud of forgetting and the cloud of unknowing [2]. The work was written in the latter half of the fourteenth century and draws on the mystical tradition of Pseudo-Dionysius the Areopagite [2]. The cloud of forgetting is not a metaphor of humility. It is an instruction to set aside what you know so that what you do not know can arrive, and the naming of forgetting as the first step tells the practitioner that the difficulty is expected.

Meister Eckhart’s version is about emptiness rather than silence. Eckhart preached detachment, and held that a man should be empty of self and all things [18]. The term outlived him in a form that can look secular: Heidegger develops his concept of Gelassenheit, or releasement, from Meister Eckhart [18]. Wu wei offers the same instruction in the Chinese vocabulary, and defines itself as not-acting or non-doing, variously translated as actionlessness, inaction or effortless action [19]. The tradition is careful about its own failure mode, because the Hongzhou sources caution against grasping onto non-doing itself as some object of attachment [19]. The contemplative literature does not claim that effort is the problem. It claims that effort about effort is the problem, and it says so inside the same tradition that teaches it.

The Buddhist analysis is the most technical and the least flattering to the seer. Upādāna is the Sanskrit and Pāli word for clinging, attachment or grasping [3], and in Buddhism clinging is considered to be the result of craving and part of duḥkha, dissatisfaction and suffering [3]. The Buddha states that there are four types of clinging, from sense-pleasure clinging through view clinging and rites-and-rituals clinging to self-doctrine clinging [3]. The self-doctrine clinging is the relevant one for the present argument, because a seer who has decided in advance what a true vision looks like is gripping the tightest object of all. Anattā, the doctrine of non-self, holds that no unchanging permanent self exists [20], and Peter Harvey argues that the more complete rendering of the term is non-Self, meaning not an essential permanent self or the possession of such a thing [20].

The last detail of that literature is the one that keeps it honest. Richard Gombrich and Alexander Wynne argue that the Buddha’s statements on the subject were originally a not-self teaching [20], and Thanissaro Bhikkhu adds that clinging to the idea that there is no self at all would actually prevent enlightenment [20]. A tradition that names its own characteristic error in this precise form has anticipated the deflationary argument from inside its own doctrine. What it does not contain, and could not contain, is a laboratory.

The deflationary case, at full strength

The deflationary case does not need a drug to run on, and it does not need a drug to win. It begins with a definition. A hallucination is a perception in the absence of an external context stimulus that has the compelling sense of reality [21]. The phrase to notice is compelling sense of reality. The definition does not include a false belief. It includes a felt quality that is indistinguishable from the felt quality of a real perception, which is precisely why a hallucination is a hallucination and not merely an error.

Once the state is defined that way, the framework explains it with no appeal to an external check. On the predictive processing framework the role of the incoming signal in determining conscious perception is much less great than on standard bottom-up views [22], and theory has equated the precision weighting that decides which signals count with what is often called attention [22]. If attention is precision weighting, and a psychedelically loosened state is relaxed precision weighting, then a loosened state is an unattended state, and the contents of an unattended state are, by construction, not checked against their source. Under this account internal noise may be misinterpreted as meaningful sensory data, which could contribute to hallucinations and spurious associations may contribute to delusional beliefs that resist updating [6].

Self-monitoring theories make the same move from the other direction. Our nervous systems distinguish self-generated from externally generated stimuli through a process of self-monitoring [22], and a state that reduces coupling within the network that builds the narrative is a state in which the distinction between in here and out there has lost its instrument. The clinical literature shows what that instrument is worth. Hallucinations occur at some point in the lifetimes of 80 percent of those with schizophrenia [23], and resting-state fMRI research has observed altered connectivity patterns within the default mode network, the salience network and the central executive network in schizophrenia [23]. The networks are the same ones. What differs is the direction of the change and whether the person is ill.

The everyday versions of the same mechanism are better documented than the spectacular ones. Confabulation is a memory error consisting of the production of fabricated, distorted or misinterpreted memories about oneself or the world [24], and confabulation can also seem to be coherent, internally consistent and relatively normal [24]. A report that is confident, orderly and internally consistent is therefore no evidence at all that its source was checked. Suggestibility is the quality of being inclined to accept and act on the suggestions of others [25], and being under the influence of suggestion can be characterized as exhibiting behavioural compliance without private acceptance or belief [25]. Belief and report come apart in ordinary life all the time, and they come apart most easily when something is asking the person to receive rather than to verify.

Expectation closes the loop. In 1985 Irving Kirsch hypothesized that placebo effects are produced by the self-fulfilling effects of response expectancies, in which the belief that one will feel different leads a person to actually feel different [26]. Confirmation bias is the tendency to search for, interpret, favour and recall information in a way that confirms or supports one’s prior beliefs, values or decisions [27]. Neither mechanism requires anything exotic. Both predict that a mind which has been handed an unusual state and asked to describe it will produce a coherent description of that state, whether or not anything unusual arrived.

Mean Drug–Placebo Difference Scores as a Function of Initial Severity - journal.pmed.0050045.g004. Photo: Kirsch, I.; Deacon, B. J.; Huedo-Medina, T. B.; Scoboria, A.; Moore, T. J.; Johnson, B. T. / Wikimedia Commons. Drug minus placebo improvement against initial severity, each point sized by the size of its trial. Source

The trial literature makes the same point quantitatively, and it does so every day without anyone calling it a vision. In a clinical trial a placebo response is the measured response of subjects to a placebo, and the placebo effect is the difference between that response and no treatment [26]. A drug that works partly because the person who takes it expects to feel different, in a study designed precisely so that nobody can expect, is the controlled version of a claim this paper has to take seriously at full strength. One account frames psychosis as the outcome of a nervous system that is operationally closed and causally open, and grounds self-monitoring in that closure [28], which is a framework in which a system that stops updating on evidence is not sick by accident but closed. That account also holds that the model is updated in content and calibrated in confidence through two routes of correction, direct sensorimotor coupling and interpersonal exchange, the latter operating only on what can be shared [28]. The psychedelic state and the psychotic state are then two outcomes of a machine with one dial, and the dial can land in either place.

The crux: control against truth

Here is where the two halves meet, and the honest answer is narrower than either side wants. The inverse relation the novel needs is real. It is visible in the imaging, where one study on the effects of LSD demonstrated that the drug desynchronizes brain activity within the default mode network, so that the activity of the brain regions that constitute the network becomes less correlated [4], and it is visible in the reports themselves, which become more confident and less accurate at the same time, since greater confidence in having performed well is associated with less accurate metacognitive judgement of the performance [8]. What is inversely related to control is not the truth of a report. It is the vividness of a report and the felt confidence in it. The evidence for that narrower claim is good, and it is not the claim the novel needs.

The Daya Bay Antineutrino Detector. Photo: Roy Kaltschmidt, Lawrence Berkeley National Laboratory / Wikimedia Commons. Two rows of photomultiplier tubes lining the walls of an antineutrino detector hall. Source

The reason is a distinction the measurement literature has made for decades. Green and Swets criticized the traditional methods of psychophysics for their inability to discriminate between the real sensitivity of subjects and their (potential) response biases [29]. A sentry in wartime might be likely to detect fainter stimuli than the same sentry in peacetime due to a lower criterion, and might also be more likely to treat innocuous stimuli as a threat [29]. Two things moved together there: sensitivity to real signal, and the tendency to call noise a threat. Vividness is the second. Confidence is the second. Accuracy is the first, and the two are separable by construction.

The neuroscience of metacognition says the same thing about the person rather than about the world. Greater confidence in having performed well is associated with less accurate metacognitive judgement of the performance [8]. That association is the single most useful sentence for this paper. A loosened controller does not merely report more vividly. It is worse calibrated, and it is worst calibrated exactly where it is most confident. The novel’s seer who sees precisely because she does not try has, in this light, a seer whose confidence is inversely related to her accuracy, which is a description of an instrument working in the wrong direction. The paper’s subject, put as plainly as it can be put, is a loosened mind and what it reports as evidence of contact.

So what could distinguish genuine receptivity from disinhibited confabulation? Four candidates, in descending order of how much they would actually settle. First, source monitoring that survives the state: a report whose origin is independently checked, which is what the reality-monitoring literature asks for and whose neural underpinnings remain unclear [17]. Second, dose-dependence and reproducibility across independent sessions, since the state that is produced by a molecule on demand and vanishes with it has an obvious alternative explanation. Third, the belief-revision account’s own admission that evidence supporting a relationship between negative belief relaxation and revision and neurobiological markers of REBUS remains elusive, alongside results the same paper describes as very preliminary [16], which is the place where the strongest receptive model is weakest. Fourth, and least, the felt quality of the experience, since a hallucination is a perception in the absence of an external context stimulus that has the compelling sense of reality [21].

The philosophical form of the worry deserves one more sentence, because the seer in the novel is in exactly the position the worry describes. Solipsism is the philosophical position that only one’s own mind is certain to exist [30], and a system whose only evidence about the world is its own unmonitored report cannot distinguish a received impression from a generated one by any operation available to it. That is not a new problem for philosophy. It is a very old one, and the contemplative tradition’s answer was never to deny it. The answer was that the apparatus required for the distinction is the thing that has to be set aside, and that what remains after setting it aside was never claimed to be a source of evidence about the external world. It was claimed to be a condition of being able to receive at all.

What an experiment would have to do is therefore not mysterious, and nothing in this paper’s sources suggests it is impossible. It would have to hold the report fixed and vary the source, which is why the field’s own work on source monitoring matters more here than any further imaging of the loosened state. It would have to survive the variable the literature names first: the outcome of a psychedelic experience is heavily influenced by the person’s mood, personality, expectations and environment, the set and setting [11]. A state that varies with expectation and then reports on expectation is the experimental form of the problem this paper has been describing. And it would have to be shown that whatever index is used is not one that rises whenever phenomenal richness rises, since entropy alterations are not specific to psychedelics or other states of heightened phenomenal richness [13]. Building them is work that lies beyond this paper.

Connecting the Dots

The dots connect in a shape that is worth drawing. The controller is a network that builds a narrative self, and the narrative self is what a person is when they are trying to see correctly. The pharmacology shows that loosening the controller produces the phenomenology the seer reports, including the subjective loss of self-identity that the literature calls ego dissolution [11]. The contemplative literature spent centuries describing the same manoeuvre in the imperative mood, and it described it in the manual that recommends cultivating two mental states, the cloud of forgetting and the cloud of unknowing [2]. The modern model of relaxed belief reads like its translation. On the receptive side of the ledger, this is a real convergence and it is not nothing: it means the rule the novel’s seer follows by intuition has a measurable correlate.

North Hemisphere Ancient Star Map. Photo: Ultima Thulean / Wikimedia Commons. A northern star map: labelled stars joined by thin lines into constellation figures. Source

The deflationary side connects just as tightly. The same network that the drug loosens is the one whose integrity separates a source from a thought, and the literature that measures source monitoring has not yet located what it needs, because the neural underpinnings for source-memory monitoring remain unclear [17]. The phenomenology that the seer calls contact is, by the standard definition, a perception in the absence of an external context stimulus that has the compelling sense of reality [21]. And the instrument that would settle the question, confidence, is one of the measures most likely to be inflated in exactly the state under examination. The two readings do not cancel. They describe the same event from the level of the controller and the level of the report, and at both levels the loosening is real.

The dots therefore connect into a shape that is smaller than the novel wants and larger than the sceptic allows. What dissolves is measurable, because an exploratory factor analysis found that all eight items of the Ego-Dissolution Inventory loaded onto a single factor [12]. What loosens is measurable, since one study on the effects of LSD demonstrated that the drug desynchronizes brain activity within the default mode network [4]. What arrives is, on the present evidence, not measurable by any means that the state itself does not contaminate.

The Other Side

The strongest honest version of the receptivity reading is this. A brain that insists on its own priors cannot be surprised by anything, because everything that reaches it has already been judged by the thing it is reaching. The seer’s rule and REBUS make the same structural claim from different centuries. The REBUS model proposes that the entropic brain state induced by psychedelics corresponds to a relaxation in the precision-weighting of neuronally encoded predictive models [16], and a relaxation of that kind is what lets a report arrive before the inspector has judged it. The cost of standing the inspector down is paid in verification. This side of the ledger is not a claim about hidden entities. It is a claim about a property of the instrument, and the property is real. Measurement is not neutral with respect to what it measures. Every account in this paper that uses the word precision is an account of measurement.

FilterFunnelApparatus. Photo: Smokefoot / Wikimedia Commons. A sintered glass filter funnel holding orange solid, above a flask of pale filtrate. Source

The strongest honest version of the deflationary reading is this. Nothing in the imaging distinguishes a loosened brain receiving something from a loosened brain generating something, because the loosening removes the comparison that would distinguish them. The evidence for the receptive reading is a correlation between a subjective report and a brain state, and the subjective report is exactly what the brain state makes unreliable: a hallucination is a perception in the absence of an external context stimulus that has the compelling sense of reality [21], and a loosened controller is a plausible setting for one. This side is not a claim that the seer is confused. It is a claim that her instrument has a known bias in the direction she needs it to be unbiased, and that a known bias cannot be corrected by the same operation that introduced it.

Both versions are strong because both are about the same fact. The fact is that a controller and a report cannot both be trusted at the moment the controller stands down. The laboratory states it in the vocabulary of calibration: greater confidence in having performed well is associated with less accurate metacognitive judgement of the performance [8]. The monastery states it in the vocabulary of detachment, where a man should be empty of self and all things [18].

What We Actually Know

Established and not in dispute: the default mode network is a large-scale network of the medial prefrontal cortex, posterior cingulate cortex, precuneus and angular gyrus that Raichle named in 2001 and that builds a coherent internal narrative central to the sense of self [4]. The drug desynchronizes brain activity within the default mode network, so that the regions that constitute it become less correlated [4]. One of the most robust findings is a psychedelic-induced acute decrease in functional connectivity within the default mode network [10]. Brain entropy is reported to be elevated during the psychedelic state [13]. Ego dissolution is measurable with an eight-item inventory whose items load on a single factor, and it is phenomenologically related to both mystical experience and psychotic states [12]. REBUS proposes that the entropic state corresponds to a relaxation in the precision-weighting of predictive models [16], and that relaxation of high-level priors may be beneficial in itself [16]. Upādāna names clinging as the mechanism whose cessation matters [3]. Plotinus’s Enneads, read as an ascetic teaching device, lead to silence and the abandonment of all intellectual inquiry [1].

Human Brain Sagittal Section. Photo: Shannan Muskopf / Wikimedia Commons. A mid-sagittal brain section whose leader lines name the precuneus and the frontal lobe. Source

Not established, and not claimed here: that a loosened controller is a more accurate one. The measurement tradition that names the distinction is signal detection theory, whose founders criticized psychophysics for its inability to discriminate between the real sensitivity of subjects and their (potential) response biases [29]. Greater confidence in having performed well is associated with less accurate metacognitive judgement [8]. A hallucination is defined as a perception in the absence of an external context stimulus that has the compelling sense of reality [21], and a definition without a content clause cannot be refuted by content. Evidence supporting a relationship between negative belief relaxation and revision and neurobiological markers of REBUS remains elusive, and the paper’s own results are described by its authors as very preliminary [16]. The neural underpinnings of source-memory monitoring remain unclear [17]. Not claimed here either: that the contemplative traditions need the pharmacology, or that the pharmacology vindicates them. The traditions predate it by centuries and make their own case, which is a case about the cost of holding on rather than about what is received when the holding stops.

References

[1] Apophatic theology — https://en.wikipedia.org/wiki/Apophatic_theology (accessed 2026-10-06) [Reputable]

[2] The Cloud of Unknowing — https://en.wikipedia.org/wiki/The_Cloud_of_Unknowing (accessed 2026-10-06) [Reputable]

[3] Upādāna — https://en.wikipedia.org/wiki/Upādāna (accessed 2026-10-06) [Reputable]

[4] Default mode network — https://en.wikipedia.org/wiki/Default_mode_network (accessed 2026-10-06) [Reputable]

[5] Executive functions — https://en.wikipedia.org/wiki/Executive_functions (accessed 2026-10-06) [Reputable]

[6] Predictive coding — https://en.wikipedia.org/wiki/Predictive_coding (accessed 2026-10-06) [Reputable]

[7] Free energy principle — https://en.wikipedia.org/wiki/Free_energy_principle (accessed 2026-10-06) [Reputable]

[8] Metacognition — https://en.wikipedia.org/wiki/Metacognition (accessed 2026-10-06) [Reputable]

[9] LSD — https://en.wikipedia.org/wiki/LSD (accessed 2026-10-06) [Reputable]

[10] Psilocybin-induced default mode network hypoconnectivity is blunted in alcohol-dependent rats — https://europepmc.org/article/PMC/10721862 (accessed 2026-10-06) [Academic]

[11] Psychedelic experience — https://en.wikipedia.org/wiki/Psychedelic_experience (accessed 2026-10-06) [Reputable]

[12] Development of the Japanese version of the Ego-Dissolution Inventory (EDI) — https://europepmc.org/article/PMC/10932788 (accessed 2026-10-06) [Academic]

[13] A critical review of brain entropy as a biomarker of the psychedelic state — https://doi.org/10.1016/j.neubiorev.2026.106720 (accessed 2026-10-06) [Academic]

[14] Dimethyltryptamine — https://en.wikipedia.org/wiki/Dimethyltryptamine (accessed 2026-10-06) [Reputable]

[15] Mysticism — https://en.wikipedia.org/wiki/Mysticism (accessed 2026-10-06) [Reputable]

[16] From relaxed beliefs under psychedelics (REBUS) to revised beliefs after psychedelics (REBAS) — https://europepmc.org/article/PMC/11779827 (accessed 2026-10-06) [Academic]

[17] External Source Monitoring and Reality Monitoring: Meta-Analysis of fMRI Studies — https://europepmc.org/article/PMC/13418370 (accessed 2026-10-06) [Academic]

[18] Meister Eckhart — https://en.wikipedia.org/wiki/Meister_Eckhart (accessed 2026-10-06) [Reputable]

[19] Wu wei — https://en.wikipedia.org/wiki/Wu_wei (accessed 2026-10-06) [Reputable]

[20] Anattā — https://en.wikipedia.org/wiki/Anattā (accessed 2026-10-06) [Reputable]

[21] Hallucination — https://en.wikipedia.org/wiki/Hallucination (accessed 2026-10-06) [Reputable]

[22] Accounting for the phenomenology and varieties of auditory verbal hallucination within a predictive processing framework — https://europepmc.org/article/PMC/5901710 (accessed 2026-10-06) [Academic]

[23] Schizophrenia — https://en.wikipedia.org/wiki/Schizophrenia (accessed 2026-10-06) [Reputable]

[24] Confabulation — https://en.wikipedia.org/wiki/Confabulation (accessed 2026-10-06) [Reputable]

[25] Suggestibility — https://en.wikipedia.org/wiki/Suggestibility (accessed 2026-10-06) [Reputable]

[26] Placebo — https://en.wikipedia.org/wiki/Placebo (accessed 2026-10-06) [Reputable]

[27] Confirmation bias — https://en.wikipedia.org/wiki/Confirmation_bias (accessed 2026-10-06) [Reputable]

[28] Operational Closure, Predictive Coding, and Psychosis: An Evolutionary Framework for Delusion, Hallucination, and Social Cognition — https://doi.org/10.31234/osf.io/be53j_v1 (accessed 2026-10-06) [Academic]

[29] Detection theory — https://en.wikipedia.org/wiki/Detection_theory (accessed 2026-10-06) [Reputable]

[30] Solipsism — https://en.wikipedia.org/wiki/Solipsism (accessed 2026-10-06) [Reputable]