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David Christopher Lane, Ph.D, is a Professor of Philosophy at Mt. San Antonio College and Founder of the MSAC Philosophy Group. He is the author of several books, including The Sound Current Tradition (Cambridge University Press, 2022) and the graphic novel, The Cult of the Seven Sages, translated into Tamil (Kannadhasan Pathippagam, 2024). His website is neuralsurfer.com

The Music Inside the Mechanism

Christof Koch, from Crick's neurons to the edge of Mind at Large

David Lane / ChatGPT Pro

I. Mountain View, March 2025

BrainMind in March 2025 was the kind of gathering that would have offended an older, narrower academy simply by existing. It braided Mountain View and Menlo Park into a single cognitive weather system: neurotechnology and contemplative science, psychedelics and AI, music and consciousness, startup fire pits and deep philosophical argument. The program itself sounded like a score written against specialization. On March 21 there was a special deep dive titled “Is Physicalism Adequate to Explain Consciousness?” featuring Heather Berlin and Christof Koch. The same day also held a session on music, brain, and health; the wider conference was threaded with musical interludes, “musical immersion,” and featured artists. Before a word was spoken, the conference had already staged the tension that would define Koch's modern career: mechanism on one side, experience on the other, with music serving as a bridge neither side could fully own.

I was there in that charged atmosphere, and what stayed with me was not merely a thesis but a vibration. Koch had spoken about the extraordinary experiences that had changed the pressure inside his thought. He spoke, as I recall it, not only about ego dissolution and oneness but about a majestic music that accompanied or framed the experience, something transportive rather than decorative, something less like soundtrack than ontology. Then came the smaller scene, the one that matters because it condensed the whole story into a few human gestures. I approached him afterward and told him about my Cambridge Elements book on the Sound Current Tradition, about the long transcultural history of inner mystical sound, of subtle audition as spiritual method, of traditions that treat listening itself as a ladder, current, or corridor through which consciousness can be altered, elevated, widened, even untethered from ordinary selfhood. The volume I mentioned, The Sound Current Tradition, is indeed about the longstanding practice of attending to subtle inner sound in meditation across religions and new religious movements, and about the different ways communities teach and interpret that listening.

What followed, in my memory, was almost comic in its immediacy and therefore all the more arresting. Koch did not retreat into the polite abstraction of a famous scientist. He did not nod in the generic way public intellectuals sometimes nod when they have already moved on. He looked startled, interested, almost personally implicated. Then he took out his phone and searched for the book—Amazon, Cambridge, the practical reflexes of an empiricist who, even when wonderstruck, still reaches first for a device, a page, a trace, a verification. It is difficult to imagine a better emblem of the man he had become. The mystical had not destroyed the investigator. It had intensified him. He still wanted the object in hand, the reference, the artifact, the trail. But now the trail led in two directions: outward toward public evidence, and inward toward forms of experience that his younger self would have treated more warily. The phone in his hand was not the opposite of awe. It was awe refusing to go soft. The old laboratory discipline had survived the visionary turn. It had merely learned to tremble.

What struck me most was not simply that Koch had changed his mind about some philosophical label. It was that his extraordinary experiences seemed to have amplified a much larger reversal. Here was one of the twentieth-century heirs to the great neurobiological hunt for consciousness, a scientist shaped by Francis Crick, somebody who had spent decades trying to locate the neural footprint of awareness in tissue, circuitry, timing, lesion, and report. And yet now he seemed to be speaking from a place where the explanatory primacy had tilted. Not away from brains, exactly. Not toward supernaturalism. But away from the idea that a complete inventory of physical mechanism, by itself, would finish the story. I was hearing a neuroscientist whose metaphysical center of gravity had shifted. Not from science to anti-science, but from certainty that the physical was enough to a willingness to say that consciousness might have to stand at or near the foundations. That is why my book landed with him. The Sound Current was not, in that moment, merely a religious-historical curiosity. It was a missing analogue, a deep archive of disciplined inner audition that suggested that the “majestic music” was not an idiosyncratic hallucination but part of an older, wider human repertoire.

To understand why that brief exchange in Silicon Valley carried such voltage, it helps to reverse the film. Before the phone. Before the beach in Brazil. Before the drumming, the chanting, the argument over physicalism. Before the old scientist learned to speak in public about idealism without embarrassment. Return to the younger Christof Koch: Catholic boy, physics-trained brain scientist, engineer of neural systems, a man whose intellectual life was formed by precisely the kind of explanatory hunger that believed mysteries ought to be dismantled, not revered. Only then does the full arc come into view. Only then does it become clear that the later mystical turn did not come from nowhere. It grew out of a decades-long pressure inside his work—a pressure generated by the very success of neuroscience at explaining everything around consciousness except the fact of consciousness itself.

II. A Catholic boy educated under Descartes

Koch's own retrospective telling begins with a biographical irony. He describes his younger self as an altar boy from a devout Catholic background, raised with a strong sense of soul, immortality, and the church's dualist anthropology. In his later book he sketches his path as a movement from “Catholic altar boy,” confident in an immortal soul, to a physics-trained neuroscientist searching for the footprints of consciousness, and then beyond. He also notes the symbolic neatness that he graduated from Lycée Descartes in Rabat, Morocco—a school named for the philosopher most associated with the modern mind-body split. The imagery is almost too perfect: a child formed by sacrament and dualism, educated under the sign of Descartes, then delivered into the machinery of late twentieth-century neuroscience. It is tempting to write that his whole intellectual life was already latent in that setup: the soul at church, the mechanism in the classroom, and the mind suspended between them waiting to become a problem.

He did not come into science as a mystic in disguise. He came through physics, computation, and neurobiology. Official bios and institutional profiles place his training in physics at the University of Tübingen and nonlinear information processing at the Max Planck Institute for Biological Cybernetics, followed by several years at the MIT Artificial Intelligence Laboratory, and then, in 1986, a faculty career at Caltech that would last roughly a quarter century. By the time he later moved to the Allen Institute in 2011, and eventually to his current role as Meritorious Investigator there while also serving as chief scientist at the Tiny Blue Dot Foundation, he had already become one of the defining scientific voices in consciousness studies. This matters because it means the later metaphysical widening did not happen on the margins of science. It happened to one of the architects of the field from inside the field's most rigorous institutions.

The young Koch did what ambitious scientists often do when confronted with a problem that philosophers had soaked in centuries of argument: he cut into it where it seemed experimentally tractable. In retrospect, this is one of the most admirable features of his career. Rather than hovering over the hard problem and performing cleverness about its insolubility, he entered the machinery. He asked which circuits mattered, which lesions abolished experience, which brain states correlated with wakefulness and perception, what happened in anesthesia, sleep, rivalry, masking, or coma. The wager underlying this style was unmistakable: start with something small and operational, and perhaps the larger mystery will eventually yield. Even his 2012 self-description as a “romantic reductionist” preserves that double impulse—reductionist in method, romantic in the refusal to flatten the subjective into mere behavior.

Yet there was always tension in him. In Consciousness: Confessions of a Romantic Reductionist, he writes that he had long believed there was “a single reality” and that science was getting increasingly better at describing it, even as he slowly lost faith in a personal God and tried to reconcile what physics could say about the world with the stubborn givenness of experience. That is a crucial early clue. Koch's later distance from physicalism was not a sudden betrayal of an earlier settled creed. The seeds were already there: a scientist uneasy with the idea that subjectivity could simply be discounted, a former Catholic who had shed orthodoxy without losing his intuition that interiority was real, and a reductionist who, even at his most mechanistic, did not actually think the mind was expendable. The later transformation did not create this tension. It detonated it.

When Francis Crick entered the story, the problem of consciousness found its unlikely modern pair of conspirators. Crick had already become one of the century's towering molecular biologists; Koch was the younger computational neuroscientist. Together they did something intellectually audacious and socially risky: they helped make consciousness respectable again as a problem for laboratory science. Today that seems obvious. In the late twentieth century it was not. Koch said in 2025 that when he and Crick started, consciousness was effectively a “no-no” topic among scientists. That single recollection reveals a great deal. They were not merely solving a problem. They were reopening a forbidden file.

III. Crick, Koch, and the neuroscientific seizure of a forbidden problem

Their 1990 paper, “Towards a neurobiological theory of consciousness,” now reads like both manifesto and reconnaissance report. It does not solve consciousness. It operationalizes a beachhead. Crick and Koch propose that visual awareness is a particularly favorable form of consciousness to study neurobiologically, precisely because it is experimentally accessible and comparatively simpler than the more reflexive forms of self-awareness. The strategy is elegantly pragmatic. Ignore, for the moment, the entire cathedral of metaphysical confusion. Find an entry point. Study visual awareness, attention, short-term memory, binding, rivalry, the neuronal coalitions sufficient for a percept. The wager is that if one aspect of consciousness can be rendered experimentally intelligible, perhaps the rest can be reached by extension. They even say quite plainly that the issue of qualia is, at least for the moment, best left to one side. That was not a denial of experience. It was tactical postponement.

The picture they drew now feels historically specific to its era, and that is part of its charm. Conscious visual awareness, they suggested, likely required attention, temporary memory, and a transient unity imposed on distributed neuronal activity. There is a distinct late-twentieth-century confidence in the language: winning coalitions, semi-synchrony, oscillations in the 40-70 Hz range, a global activity distributed across cortical areas, and the hope that careful neurophysiology would progressively narrow the explanatory gap. Their conclusion is one of those sentences that, once read, stays with the reader because it compresses an entire scientific temperament into a few words. When we can construct such machines and understand their detailed behavior, they suggest, “much of the mystery” may disappear. That is early Koch in one line: bold, empirical, impatient with fog, convinced that what looks metaphysically ineffable may partly owe its status to the current poverty of our models.

What is easy to forget is how radical this move was even before any theory proved right or wrong. Crick and Koch insisted that there is something here that requires scientific explanation. That sounds innocuous now; it was not then. Their paper assumes, without apology, that consciousness is neither sacred remainder nor merely linguistic confusion. It is a biological fact, or rather a set of facts, waiting to be anatomized. And yet even in that early text there are hints of the problem that would later force Koch beyond simple reduction. The very need to isolate “the exact neural correlate” of seeing red betrays an unease. Correlate is not explanation. Correlate is a necessary prelude, a footprint, a trail in mud. It tells us where the animal stepped, not what the animal is. The field they helped found would spend the next decades learning the difference.

The practical tools of that period tell the same story. Binocular rivalry became an experimental darling because the stimulus could remain constant while the conscious percept alternated. Anesthesia offered a way to compare brain states with and without reportable awareness. Lesion studies, disorders of consciousness, and masking paradigms let researchers separate what is processed unconsciously from what enters the lit chamber of experience. This was consciousness science in its most disciplined, unromantic form: stripping away stories, using perturbation and contrast, refusing to be overawed by the phenomenon. Koch's collaboration with Crick also later culminated in their fascination with the claustrum, the thin sheet-like structure tucked beneath the cortex that receives input from much of cortex and projects widely back. Their final joint article speculated that it might play a key role in binding disparate cortical activities into unified percepts. Allen Institute materials later summarized this with the memorable metaphor of the claustrum as a “conductor of the cortical symphony.” Even here, notice the musical language creeping in through the side door of anatomy.

There is a temptation, in retrospect, to make Crick the hard materialist and later Koch the apostate. That is too neat. Crick and Koch were never crude eliminativists. Their enterprise was more interesting than that. They were trying to make subjectivity scientifically legible without surrendering its reality. The phrase “neural correlates of consciousness” was itself a careful piece of intellectual carpentry. It did not claim to have reduced experience to neurons. It named the minimum neural mechanisms sufficient for a given conscious content. In 2025 Koch said exactly this: the NCC program is neutral with respect to metaphysics. That neutrality mattered. It created a space in which one could do empirical work without pretending that empirical work, by itself, had already settled what consciousness ultimately is. But neutrality is unstable. Once the correlates accumulate, pressure builds. Either they begin to suggest an ontology, or they expose the insufficiency of the frameworks that made them possible. Koch's later work is the history of that pressure becoming unbearable.

Crick died in 2004. The older partnership ended, but the problem did not. In some sense the rest of Koch's career can be read as a long answer to a question Crick helped sharpen and then left unfinished: suppose we can increasingly identify where consciousness is likely happening in the brain. What then? What sort of thing have we found? A correlation? A mechanism? A function? A causal structure? A metaphysical clue? Or a border marker showing where neuroscience stops being comfortably physicalist and begins, despite itself, to trespass into ontology? That question would slowly pull Koch away from the simpler dream that neuroscience alone could finish the job. It would also, eventually, make him unusually open to the authority of extreme first-person states. But before it reached the beach in Brazil, it had to pass through the cortex.

IV. From footprints to fault lines

Koch's mature empirical work is, in one sense, the refinement of the original Crick program. In a 2016 review, "Neural correlates of consciousness: progress and problems", coauthored with Marcello Massimini, Melanie Boly, and Giulio Tononi, he laid out a much more careful taxonomy of the neural correlates of consciousness. There are enabling factors, they argued—brainstem arousal systems, metabolic support, the general conditions that make consciousness possible—but these are not the NCC proper. There are content-specific NCCs, responsible for particular experiences, and perhaps a full NCC, the union of mechanisms sufficient for any conscious scene. That framework may sound technical, but conceptually it mattered. It forced the field to stop confusing prerequisites, reports, and consequences with consciousness itself. Once again, Koch was cutting the problem finer. But every refinement also pushed the mystery into sharper relief.

The most influential empirical consequence of this later phase was the growing emphasis on the back of cortex—the temporo-parietal-occipital regions sometimes described as the “posterior hot zone.” In the 2016 review, Koch and colleagues argued that the best anatomical candidates for the contents of consciousness were concentrated primarily in posterior cortical regions rather than in the prefrontal theater long favored by more workspace-oriented accounts. Prefrontal activity, on this picture, often tracked attention, task demands, decision, introspection, report, or control rather than the raw presence of experience itself. This did not mean frontal cortex did nothing important; it meant the field had been too quick to conflate the machinery for talking about a conscious state with the machinery constituting it. That distinction became one of Koch's signature scientific convictions.

The cerebellum sharpened the point almost brutally. It contains vastly more neurons than the neocortex—Koch often notes roughly four times as many as the rest of the brain combined—yet damage to it can devastate coordination without annihilating ordinary subjective life. In his 2024 book he presses the lesson hard: billions of cerebellar cells can be firing, releasing neurotransmitter, doing their exquisitely organized work, and still not generating experience in the way cortex does. That observation “refute[s] the myth,” he writes, that consciousness simply arises from neurons doing what neurons do. What matters is not neural stuff per se. What matters is structure, connectivity, recurrent architecture, the right kind of causal organization. The line from here to Integrated Information Theory is almost a straight road.

This is where Koch's scientific journey becomes philosophically consequential. The early field had sometimes sounded as if enough neurons, firing in the right synchrony, might dissolve the mystery. The later Koch increasingly argues that mere quantity or activity is not enough. A feedforward or modular architecture may compute beautifully and remain experientially thin. A densely recurrent architecture may matter because it has causal powers upon itself. In other words, the question is no longer merely where activity happens, but what kind of system the activity inhabits. The explanatory unit shifts from local firing to intrinsic organization. Once that happens, the older physicalist picture starts to wobble. Not because physics is false, but because a purely extrinsic description of matter in motion does not tell us why some organized systems feel like something from within. Koch's science itself pushed him into this impasse.

Notice how different this is from a simple renunciation of material explanation. Koch did not stop caring about lesions, anesthesia, sleep, coma, masking, or cortex. He did not retreat into private revelation and declare the laboratory obsolete. He became more exacting, not less. But exactness can be corrosive. The cleaner the empirical distinctions became, the harder it was to pretend that functional description alone had solved the existence of experience. A field built to hunt correlates slowly discovered that correlations are footprints, and footprints can lead to a cliff. Once Koch reached that cliff, he turned toward IIT.

V. The romantic reductionist crosses into ontology

One of the most important corrections to the popular story is chronological. The shift in Koch's metaphysics did not begin with late-life psychedelics. It had already advanced significantly by 2012. In Consciousness: Confessions of a Romantic Reductionist, Chapter 8 is bluntly titled as an argument that consciousness is “a fundamental property of complex things.” There Koch says that experience may “never be fully reduced” to the physical properties of the brain and that consciousness is a fundamental, elementary property of organized living matter. He even goes on to say that any and all systems of interacting parts possess some measure of sentience, with larger and more highly networked systems possessing more. This is not strict physicalism. It is already a decisive widening, and it places Koch well down the road toward what he would later say more openly in public. The later mystical experiences intensified and existentially charged this view, but they did not invent it.

The architect of that widening was Giulio Tononi's Integrated Information Theory, which Koch became one of the most visible defenders of. The simplest public gloss is that consciousness is not fundamentally a function or a computation but a form of intrinsic causal organization—a structure in causal space corresponding to what experience feels like from within. In a 2025 conversation with Sean Carroll, Koch says consciousness is “not a clever hack,” not merely a computation, but “a state of being,” a system's causal power upon itself. The more irreducible the whole is relative to its parts, the higher its integrated information, or phi. The theory is ambitious because it tries to derive the properties of physical substrates from the properties of experience, rather than the other way around. Whether one thinks that project succeeds is another matter. But as an intellectual move it explains why Koch could no longer remain satisfied with a purely correlational neuroscience. IIT did not just localize consciousness. It tried to tell him what kind of thing consciousness is.

This is also where Koch becomes “panpsychist-adjacent,” to borrow Sean Carroll's phrase. IIT implies a graded view of consciousness. There is no magical threshold at which subjectivity suddenly snaps into existence. Systems with sufficiently integrated causal organization have some degree of experience; systems with none do not. Koch explicitly embraces the intuition that many animals likely feel like something, and his 2019 book, The Feeling of Life Itself, presents consciousness as more widespread than previously assumed and not reducible to computation. Tononi and Koch had already framed IIT in public-facing terms as implying that consciousness is graded and common among biological organisms, perhaps extending to some simple systems, while ruling out purely feedforward networks or mere aggregates such as a heap of sand. That is why Koch is willing to entertain a scientifically disciplined form of panpsychism while still resisting the caricature that “everything is richly conscious.” His universe is not cartoon animation. It is a hierarchy of causal interiors.

At the same time, IIT gave Koch a way to resist one of the reigning orthodoxies of Silicon Valley: computational functionalism. On that view, if a system performs the right functions—planning, reporting, memory integration, flexible control—then consciousness follows regardless of substrate. Koch's answer is increasingly hard-edged. In recent interviews and in his 2024 book, he argues that simulation is not constitution. A computer can simulate rain without getting wet, simulate a black hole without bending spacetime around the laptop, and simulate a person without thereby becoming a subject of experience. What matters, on his account, is not externally measured input-output equivalence but intrinsic causal powers. This is why he is skeptical that today's large language models are conscious, however eloquently they speak about feeling. They have swallowed human descriptions of feeling; that is not the same as feeling. A 2024 paper coauthored by Koch on AI and consciousness pushes the same point more formally: functional equivalence need not imply phenomenal equivalence.

Here the resonance with my own “virtual simulator” idea becomes both real and delicate. Koch does not endorse the simulation hypothesis in the usual cosmological sense; he is explicitly skeptical of it. But he does repeatedly argue that the mind constructs what it takes to be reality from priors, expectations, and learned statistical regularities. In Then I Am Myself the World he says the mind is not a passive recipient of sensory data but constructs its reality, and in his work with the Tiny Blue Dot Foundation he even speaks of human beings as living in “mental worlds of their own making,” their “Perception Box.” This is not the claim that the universe is literally a computer simulation. It is closer to a constructive or generative view of consciousness as world-rendering, world-editing, and world-framing from the inside. In that weaker but philosophically potent sense, my simulator metaphor really does dovetail with Koch's later language. Consciousness is not just a passive light. It is a maker of appearances.

And yet, for all this metaphysical expansion, Koch still did not become vague. IIT is attractive to him precisely because it claims measurability. Phi may be difficult to compute in large real systems, but the theory is not supposed to be poetry alone. It makes anatomical and dynamical predictions: cortex over cerebellum, recurrent over feedforward, irreducible wholes over loosely assembled parts, posterior hot zone over unconstrained prefrontal broadcast. This is important for the story because it shows why Koch could move away from physicalism without abandoning scientific seriousness. His route was not: I had a vision, therefore science is broken. His route was: my science already pushed me toward a theory that grants consciousness ontological seriousness, and certain experiences later made that seriousness impossible for me to treat as merely abstract. The order matters. Without IIT, the mystical states might have remained private astonishments. With IIT, they became existential corroborations of a tendency already present in the theory.

VI. Losing the bet, hardening the science

The public symbol of this middle period was the famous wager with David Chalmers. Back in 1998, in a bar after a consciousness meeting, Koch bet Chalmers a case of wine that within twenty-five years researchers would identify a clear neural signature or mechanism of consciousness. Chalmers bet otherwise. In June 2023, Koch lost. Nature summarized it with cheerful cruelty: philosopher 1, neuroscientist 0. Scientific American described the settlement of the case of wine. It is easy to read the lost bet as a humiliation; it is better read as a measure of Koch's seriousness. He had bet on progress because he genuinely believed the field would close on a robust answer. Losing the bet did not make him anti-scientific. It made the incompleteness of the field publicly undeniable. The cliff edge had become theatrical.

What makes Koch interesting is what he did next. He did not declare defeat and drift into pure speculation. He doubled down on adversarial, preregistered, collaborative theory testing. The large COGITATE collaboration that culminated in a 2025 Nature paper was designed precisely to move beyond the bad incentives of consciousness research, where each camp can confirm itself with friendly paradigms and selective interpretation. The consortium brought together proponents of IIT and Global Neuronal Workspace Theory, developed differential predictions in advance, preregistered pass/fail criteria, and then tested them across fMRI, MEG, and intracranial EEG in 256 human participants viewing suprathreshold stimuli of varying durations. Whatever else one says about consciousness science, this was the field trying to grow up in public. Koch was part of that maturation.

The result did not crown a victor. That, too, is central to the story. The Nature paper concluded that the data aligned with some predictions of IIT and GNWT while “substantially challenging key tenets of both theories.” For IIT, the lack of sustained synchronization within posterior cortex counted against one claim about network connectivity specifying consciousness. For GNWT, there was a general lack of the predicted ignition at stimulus offset and only limited representation of certain conscious dimensions in prefrontal cortex. The lesson was not that consciousness science was futile. The lesson was that even its most serious theories remain unfinished. Koch's favored framework took damage. He stayed with it. That combination—public theory testing plus philosophical stubbornness—is part of what gives him credibility even when his metaphysics outruns consensus.

This also clarifies the changing meaning of “physicalism” in his speech. Early on, one might have thought the neuroscientific task was simply to find the right brain pattern, after which the metaphysics would take care of itself. The bet's failure, the adversarial results, and the persistence of the hard problem all changed the atmosphere. By 2025 BrainMind could host an explicit session asking whether physicalism is adequate, with Koch as one of the featured discussants. By April 2026 the Bial Foundation could officially advertise his keynote as an argument that extraordinary experiences such as near-death experiences should lead us to question physicalism, while noting that Koch defends idealism and panpsychism as compatible with naturalism and scientific method. That is not the language of a scientist who thinks a few more electrodes will automatically close the case. It is the language of someone who now believes the science itself has reopened metaphysics.

But here is the crucial subtlety: Koch's science hardened even as his metaphysics widened. He still insists, in his own book, on what he calls the neuroscientist's dictum: “No brain, never mind.” He is skeptical of afterlife claims based on near-death narratives. He does not take mystical states as proofs of supernatural intervention. In the same pages where he describes extraordinary experiences as revelatory, he insists that thoughts, memories, and percepts are consequences of the brain's natural causal powers. This tension—radical first-person seriousness combined with continued insistence on brain substrate—is what makes him so unusual. He has not crossed from science into revelation. He has moved from a flat ontology to a stratified one, where experience is basic enough to demand metaphysics but not exempt enough to escape physiology.

By the time I heard him in March 2025, then, I was not witnessing a sudden conversion. I was seeing the public phase of a long transit: from correlates, to causal architecture, to ontological unease, to open sympathy for metaphysical positions earlier generations of scientists would have dismissed as career-threatening. The reason his response to my Sound Current work felt so electric is that he had already come to suspect that first-person states are not ornamental data. They are part of the phenomenon to be explained. And some of those states seem to arrive, across cultures, with sound.

VII. Brazil, music, and the ontological shock

My memory locates the decisive mystical turn in Brazil, and Koch's published record places the ayahuasca ceremonies most clearly associated with his metaphysical shift in Bahia, Brazil. In this case memory and record converge. South America, jungle medicine, oneness, transportive sound, a scientist coming back with his ontology rattled—that is the kernel. In print, Koch writes of participating in communal Santo Daime ceremonies in Bahia featuring hours of praying, meditating, drumming, chanting, dancing, and drinking ayahuasca in forest and on beach under the southern sky. There, he says, he experienced something “wonderous—Mind at Large,” which led him to question the metaphysical worldview he had grown comfortable with and to ask whether everything might be “a manifestation of the mental.” That is not a rumor or hostile gloss. It is Koch's own account.

But the musical thread in his altered-state writing begins even earlier and in several different keys. The title of his 2024 book, Then I Am Myself the World, is taken from Wagner's Tristan und Isolde. Koch describes encountering the opera on a “scrappy radio” and being transfixed for days. This is not incidental ornament. The title itself turns ecstatic union into the book's governing metaphor. In the introduction he links that Wagnerian aspiration—to transcend the mundane and merge with an ultimate realm of being—to the very states he will later discuss under mystical, psychedelic, and near-death rubrics. Before ayahuasca, before Brazil, music already functioned in his life as a technology of derangement, transport, and ontological longing. To say that he later heard or felt something like majestic music at the edge of a oneness experience is not a bizarre discontinuity. It is entirely consonant with how his imagination had long been organized.

Then there is the 5-MeO-DMT episode, which is distinct from the Santo Daime ceremonies but essential to the full picture. Koch's book opens with this experience of ego death and reentry. He recounts sitting cross-legged as his guide started the music he had chosen—Arvo Pärt's “Spiegel im Spiegel”—before he inhaled the compound and passed into an overwhelming state where self, body, space, and ordinary structure dissolved. When the world began to return, the first sign of the outside intruding into his “marooned mind,” he writes, was the closing notes of Pärt's piece. That scene is almost unbearably precise: consciousness stripped to terror and ecstasy, then the world reassembling itself first as sound. If one wanted a single documentary image for the thesis that music can serve as a threshold medium between ontological regimes, Koch himself has already supplied it.

He is explicit about what these experiences did and did not do to him. In the Sean Carroll conversation, he says his brain was of course the substrate of the experience; he does not doubt that “for one second.” But he also says the experience brought what William James would call a noetic authority, something that “shook the ontological foundation” and made him “much more sympathetic to idealism.” He describes the self as completely gone, Christof gone, body gone, and the universe at large somehow present instead. That is the crucial modern Koch in compressed form: not brain-denial, not supernatural certitude, but an empirically trained mind admitting that a class of experiences has altered what he thinks reality is like. He appeals to James because James offers a vocabulary for this predicament: the experience does not coerce others, but it can reorder the experiencer's metaphysics.

This is exactly why the phrase “pure idealist” goes a step too far. Koch still resists making the mystical state into a trump card. He still wants reconciliation with neuroscience. In the same conversation he says he remains a rational scientist and tries to ask how what he experienced is compatible with everything else he knows, including brain science. In his book he remains skeptical of using near-death experiences as proof of an afterlife, insisting that extraordinary claims require extraordinary evidence and that a silenced brain does not, on present evidence, support consciousness. Even when he reaches for Schopenhauer or speaks of a universal field of consciousness, he does so while explicitly acknowledging how such claims sound. The result is not a conversion narrative in the religious sense. It is closer to an ontological destabilization that the scientific self then tries, painstakingly, to metabolize.

My memory of the “majestic music” belongs here. I cannot certify the exact wording. But I can say this: the public record is already saturated with adjacent material. Koch's altered-state writing includes Wagnerian rapture, Arvo Pärt at the threshold of ego death, Santo Daime's drumming and chanting, and even a report of hearing “a rhythm, the beating heart of the cosmos.” In other words, sound is not a stray embellishment to his mystical turn. It is one of its recurring vehicles. This is why my conversation with him mattered. I was not introducing a random religious curiosity to a neuroscientist. I was offering a cross-cultural archive for a sensory channel that had become existentially charged in his own life. What looked like amazement on his face may have been recognition.

And that is where my Sound Current work enters the story as more than anecdote. Cambridge describes the tradition as the practice of listening to subtle inner sound during meditation to concentrate and elevate the mind, a practice with a long history across multiple religions and new religious movements. That description does not prove any metaphysical thesis. But it does establish a historical fact of enormous relevance: disciplined inner audition has functioned, across cultures, as a repeatable spiritual technology. Once that is on the table, Koch's music-inflected altered states look less like idiosyncratic psychedelic decoration and more like contact with a recurrent human method of consciousness modulation. Whether one explains that method in terms of attention, predictive coding, self-model attenuation, neural quieting in posterior cortex, sacred sound, or all of the above, the archive cannot simply be waved away. My conversation effectively placed that archive in his hand.

VIII. What changed in Koch—and what did not

So what, in the strictest sense, changed? Early Koch, especially in the Crick years, treated consciousness as a tractable biological mystery. The strategy was to localize and characterize the neural coalition sufficient for experience. Later Koch still values that work, but he no longer believes that the physicalist picture in which matter is fundamentally observer-independent mechanism and consciousness is somehow retrofitted afterward can adequately account for what is immediately given in experience. In 2025 he says bluntly that “the mental is clearly not physical,” and that the idea that everything is just physical has long struck him as untenable. In 2026, according to the official Bial symposium materials, he is publicly framing extraordinary experiences and the hard problem as reasons to challenge physicalism and to reconsider idealism and panpsychism. What changed, then, was not his commitment to the brain. It was his willingness to say that the brain does not settle the metaphysical status of experience.

What did not change is equally revealing. He still wants theories that make discriminable predictions. He still participates in preregistered adversarial collaborations. He still distinguishes the real from the simulated by causal power rather than by rhetoric. He still thinks current digital computers and LLMs are probably not conscious. He still believes the cerebellum's architecture teaches us something decisive, that the posterior hot zone matters, that feedforward organization is not enough, that causation internal to a system matters more than mere input-output behavior. And he still returns, again and again, to the demand that whatever metaphysics we entertain must stay answerable to the structure of experience and the structure of brains alike. His turn has been dramatic, but it has not been a retreat into vagueness. It is, rather, a wager that metaphysics need not be the enemy of measurement.

This is also why my notion that consciousness is a “virtual simulator” can be made fruitful in dialogue with Koch, provided the phrase is handled carefully. Koch would reject the stronger thesis that reality itself is a digital simulation; he is explicit about that. But he would endorse, in substance, the claim that each mind constructs a bespoke experienced world from priors and expectations, and that transformations of the self-model can radically transform the apparent world. In his current vocabulary, extraordinary states can expand the “Perception Box.” In my language, consciousness simulates or renders a world from within. These are not identical metaphysics, but they rhyme. And when sound—outer or inner—modulates attention deeply enough, the simulator changes its rendering. The world can become larger, emptier, more luminous, less ego-bound, more musical, more unitary. Whether one calls that Bayesian reweighting, posterior cortical quieting, mystical ascent, or Shabd, the phenomenological family resemblance is hard to ignore.

Koch himself gestures toward this family resemblance in a striking passage. He argues that transformative experiences—religious, mystical, psychedelic, near-death—provide clues about consciousness because they show that self is optional, that even the feeling of having a body is not necessary for subjectivity. He suggests that these classes of experience may share a common neurobiological substrate and speculates that minimal activity in the posterior hot zone could be associated with states of vast, empty expanse, no narrative self, and no distinction between experiencer and experienced. That proposal is scientifically controversial, but narratively it matters because it shows where Koch is headed: altered states are not noise in the data. They are privileged perturbations that reveal which features of ordinary consciousness are contingent and which are fundamental. For someone interested in mystical sound traditions, that is an invitation. It suggests that the history of contemplative audition may belong, not outside consciousness science, but at one of its frontiers.

And so the scene at BrainMind takes on a new shape. I was not simply talking to a celebrated neuroscientist after a conference talk. I was standing at the crossing point of several long rivers: Crick's empirical courage, the NCC program, IIT's causal ontology, the failure of the easy physicalist confidence, the discipline of adversarial testing, the authority of ego-dissolving states, and the ancient conviction found in multiple traditions that sound can be a vehicle of ascent. No wonder he reached for his phone. The moment was not ornamental. It was catalytic. A scientist who had come to suspect that first-person extremes matter had just been handed a historical map of one such extreme. My book, in that instant, was not just a book. It was a missing archive for an experience he now knew from the inside.

IX. The long return: from neuron to note, from note to world

There is a way of telling Koch's story that turns it into a melodrama: first the hard-nosed neuroscientist, then the psychedelic sage. That story is false because it misses the continuity. A better telling is that the neuroscience itself produced the crisis. The more carefully Koch and others tracked the footprints of consciousness, the less convincing it became that consciousness could be explained as mere externally describable function. Correlates were real; they were not enough. Architecture mattered; it did not by itself tell us why there is something it is like to be that architecture. IIT arrived as an attempt to give the inside of a system its due. Mystical experience arrived later as a first-person pressure test on the possibility that consciousness is more fundamental than a late-arriving surface froth on mechanism. Sound—Wagner, Pärt, drumming, chanting, the rhythm of the cosmos, and the Sound Current lineage I trace—kept appearing because sound is one of the oldest ways human beings have learned to reorganize attention and selfhood. This is not a betrayal of Koch's research. It is its widening spiral.

Seen this way, the apparent contradiction in Koch resolves into a paradox productive enough to animate the next generation of work. He is both more empirical and more metaphysical than the stereotype of the reductionist scientist allows. He continues to maintain that the brain remains the substrate. He also argues that physicalism is inadequate. He participates in theory-neutral collaborations that wound his own favored theory. He also says that extraordinary experiences shook the foundations of his worldview and made him more sympathetic to idealism. He rejects the idea that language models become conscious by talking about feelings, yet he argues that subtle changes in causal organization can make the difference between a merely behaving machine and a subject. He continues to insist on posterior cortex, cortical architecture, recurrent circuitry, and the causal powers of organized matter, while simultaneously granting a seriousness to mystical consciousness that earlier generations of laboratory scientists would have treated as contamination. None of this is incoherent. It is the shape of a field coming to terms with its subject matter.

My own intuition about mystical music sharpens the final image. Perhaps consciousness is indeed a kind of virtual simulator—not in the cheap sense that reality is fake, but in the stronger phenomenological sense that what we live in from moment to moment is a rendered world, assembled from priors, memory, embodiment, expectation, and attention. If so, sacred or inner sound traditions matter because they are not peripheral devotions. They are parameter hacks on the simulator. They alter weighting, stabilize attention, weaken self-referential narration, intensify salience, and may open the rendered world into states it does not ordinarily show. Koch's later work offers a neurophilosophical grammar for why such practices might matter. My Sound Current work offers a civilizational archive showing that humans have been exploring that portal for a very long time. Where they meet is not proof. It is possibility. And possibility, in consciousness studies, is often the precondition of discovery.

By April 2026 the public record shows Koch standing ever more openly in this widened terrain. The Bial Foundation's program describes him as using extraordinary experiences and the failure of physicalism to explain consciousness as grounds for looking again at idealism and panpsychism. Yet the same official bio on that page still defines him through biophysics, cortex, circuits, and detecting consciousness in behaviorally unresponsive patients. That is the whole story in miniature. The man did not stop being a neuroscientist when he crossed into metaphysics. He became a neuroscientist who could no longer pretend metaphysics was optional. He did not abandon the mechanism. He started asking what kind of world must exist for mechanism ever to feel like something from within.

And so let the story end where it began: not in a jungle or on a beach, but in Mountain View, with a scientist holding a phone. Around him, a conference designed to braid music and mind, physicalism and its critics, contemplative practice and neurotechnology. In front of him, I carried an older archive of listening—the history of people who believed that sound, especially inner sound, could alter the shape of consciousness itself. In him, the whole arc of late modern consciousness science: Crick's laboratory daring, the hunt for neural correlates, the posterior hot zone, the cerebellum's lesson, the rise of IIT, the loss of the bet, the dignity of failed predictions, the refusal of current AI hype, the beach in Brazil, the noetic aftershock, the widened sympathy for idealism, the search for a book that might help him place his own experiences inside a larger human grammar. It is a beautiful image because it is so modest. No revelation on the spot. No conversion. Just curiosity, recognition, and the old scientific instinct moving toward evidence. But the evidence, now, included music.

Coda

The deepest sentence one can write about Koch's evolution is not that he moved from brain to spirit, or from science to mysticism, or from physicalism to idealism. It is that he moved from thinking consciousness could be understood by locating the right mechanism to thinking that locating the mechanism forces us to rethink what counts as real. The mechanism remained. The world around it changed.

And perhaps that is why the music matters so much. For Koch, as the record now shows, music is not merely accompaniment. It appears at the threshold of dissolution, at the return from ego death, in the ceremonial surround of ayahuasca, in the Wagnerian title of a book about boundlessness, and in the remembered rhythm of the cosmos itself. For me, with The Sound Current tradition in hand, that recognition came all at once. What I heard in Koch was not just a scientist reporting an altered state. I heard the modern laboratory, after a long detour through cortex and causation, rediscovering that consciousness has always had an acoustic edge. The old traditions knew it. Koch seems to have glimpsed it. And that may be one of the most tantalizing developments in consciousness research right now.