Neven's Quantum Superposition Formation

Hartmut Neven, the physicist and computational neuroscientist who founded and leads Google Quantum AI, locates the physical substrate of consciousness in a single, precisely specified quantum-mechanical event: the formation of a superposition. The theory, developed with colleagues, proposes that conscious experience is generated not by classical computation and neural information processing alone, nor by the collapse of a quantum state, but by the creation of a quantum superposition itself: “Conscious experience arises whenever a quantum mechanical superposition forms” (Neven et al., 2024). Neven's position is distinguished from the broader family of quantum-mind hypotheses by both his formation conjecture and his claim that it can, in principle, be tested experimentally.

Neven’s theory is founded upon two convictions. First, consciousness is the one datum that cannot be eliminated. He says, “Everything starts from experience; without mind, nothing matters” (Lewton, 2024). Second, classical physical descriptions seem ill-suited to explaining why experience is unified, definite, qualitative, and perhaps agentive. Quantum mechanics, by contrast, already contains superposition, entanglement, branching, basis-selection, and non-classical uncertainty—phenomena that can conceivably map onto central features of phenomenal consciousness.

Following and Revising Penrose

Neven follows Penrose, with a twist. "I'm a disciple of Roger Penrose," he told New Scientist (Lewton, 2024), referring to the 1989 proposal in The Emperor's New Mind that a conscious moment occurs when a gravitationally induced superposition "collapses"—Penrose's "objective reduction" (Penrose, 1989)—and the later Penrose–Hameroff Orch OR theory that posits a real physical collapse, possibly involving gravity, in neuronal microtubules. Neven finds the original idea "beautiful" because, on it, qualia "can naturally be encoded into the state that [the superposition] collapses into" (Lewton, 2024). Yet he argues the proposal "is in need of refinement" on three counts, none of which is trivial (Neven et al., 2024).

First, he removes gravity. Whether gravitational influence induces collapse may be testable, but laboratory searches have so far come up empty (Donadi et al., 2021); Neven prefers classic decoherence, in which an "effective collapse" occurs when a quantum system becomes entangled with an environment of many degrees of freedom (Neven et al., 2024).

Second, and most consequentially, he inverts the temporal locus of experience. Where Penrose tied consciousness to collapse, Neven ties it to the birth of the superposition. The motivation, he claims, is to be consistent with governing law. If a conscious experience were shared across spatially separated entangled qubits at the moment of collapse, one could, by measuring locally, in principle, signal "faster than the speed of light" (Neven et al., 2024)—a violation of special relativity. Moreover, standard quantum mechanics forbids using entanglement for superluminal information transmission. Neven resolves the difficulty by repositioning the conscious moment to formation, which "sidesteps the conceptual problem of having to define when exactly a measurement occurs" (Neven et al., 2024).

Third, Neven’s framework is "firmly rooted in Everett's 'many worlds' formulation" (Neven et al., 2024), the universal wavefunction does not literally collapse; rather, decoherence yields effectively separate classical branches. Here lies his answer to the obvious objection that no one experiences a superposition. On Neven's reading, "a system only ever experiences classical, definite states" (Neven et al., 2024). When a definite state evolves unitarily into a superposition, the experiencing system follows multiple "Feynman paths" simultaneously, each yielding "a distinct sequence of conscious moments," so that a quantum system "may be composed of many experiencing minds, albeit often very simple ones" (Neven et al., 2024). Consciousness, on this picture, is "how we experience the emergence of one unique classical reality from the many the multiverse [quantum] is composed of" (Neven et al., 2024). Thus, each conscious moment is not a mysterious exception to physics, but the first-person aspect of a quantum system’s branching into definite classical experience. [Note: Neven's many-worlds framework is informed by working at the frontier of quantum computing: a calculation Google's Willow processor performed, he notes, would take a classical supercomputer some 10²⁵ years, a result he reads as "tapping into something larger than just our universe" (Lewton, 2024). It is a view not generally supported by most mainstream physicists.]

Qualia, binding, agency

Three implications follow. Neven’s theory makes a direct claim about qualia: the qualitative character of experience is determined by the structure of the superposition (Neven et al., 2024). A system does not experience “superposition” as such; it experiences definite classical basis states along Feynman paths. In this sense, phenomenology is classical from the inside, even though its physical substrate is quantum.

Entanglement, in turn, supplies a natural solution to the binding problem—the unity of phenomenal experience (Treisman, 1996). "Entanglement is the only true binding agent we have in physics," Neven argues, "as it allows for the creation of holistic states where individual components are fundamentally interconnected" (Lewton, 2024). The richness of an experience is bounded by the number of degrees of freedom entangled (Arkhipov, 2022)—on Neven's estimate, the binding of "hundreds of qubits, if not thousands or more" is required to capture the textures of a single subjective moment (Neven & Koch, 2024).

Finally, the formation of a superposition "may go hand-in-hand with a moment of agency" (Neven et al., 2024). Once a quantum system reaches roughly 100 entangled qubits, an external observer cannot, even probabilistically, predict its evolution—a condition the authors liken to "Knightian uncertainty" (Aaronson, 2016; Neven et al., 2021).

Is free will hiding here? The team conjectures that an organism may exercise genuine choice over which classical configuration it experiences next. They ground this in a "homeostatic correlation": pleasure tracks behaviors that sustain the organism, pain those that threaten it, a coupling that, they argue, would be evolutionarily pointless for a deterministic automaton (Neven et al., 2024). It follows that "Turing machines have become intelligent but may never become conscious"; sentience, on this view, requires "a quantum Turing machine" (Neven et al., 2024).

An experimental program

Neven's ambition is to rigorously test the hypothesis that human consciousness is a quantum phenomenon. To do so requires addressing the chronic obstacle—that experience "is not a traditional experimental observable" (Neven et al., 2024). Neven’s proposed experimental framework is an “expansion protocol” that seeks to physically link a human brain to a quantum computer via quantum entanglement. This requires coupling N qubits in a subject's brain to M qubits in a processor to form an N+M superposition.

The proposed test is phenomenological: ask subjects to report their experiences while measuring the quantum state of the coupled system. If the conjecture holds, the subject should report "a richer experience" requiring more bits to describe. In principle, this could allow researchers to correlate specific quantum states with specific qualia—perhaps even to calibrate specific experiences. Neven and collaborators speculate that psychedelic, mystical, and near-death experiences may involve increased numbers of entangled qubits within the brain, though this remains highly conjectural (Neven et al., 2024). Moreover, he claims that the timing of that enrichment would discriminate his formation hypothesis from Penrose's collapse version.

There is a technical complexity. Quantum superposition is basis-dependent. Which basis corresponds to experience? Neven et al. consider several possibilities: Deutsch’s “interpretation basis,” Zurek’s “pointer-state basis,” or a basis selected by maximizing quantum integrated information (Neven et al., 2024). Neven’s theory is not Integrated Information Theory, but it may borrow quantum-IIT Φ-measures to quantify the amount and structure of experience (Zanardi et al., 2018; Albantakis et al., 2023).

Entangling a human brain with a quantum computer, Neven says, could “expand consciousness in space, time and complexity.” Invoking Thomas Kuhn, he holds that consciousness research has reached a "pre-paradigmatic" inflection point (Lewton, 2024).

References

Aaronson, S. (2016). The Ghost in the Quantum Turing Machine. Cambridge University Press.

Albantakis, L., Prentner, R., & Durham, I. (2023). Computing the Integrated Information of a Quantum Mechanism. Entropy, 25(3), 449.

Arkhipov, A. (2022). Non-Separability of Physical Systems as a Foundation of Consciousness. Entropy, 24(11), 1539.

Donadi, S., Piscicchia, K., Curceanu, C., Diósi, L., Laubenstein, M., & Bassi, A. (2021). Underground test of gravity-related wave function collapse. Nature Physics, 17, 74–78.

Lewton, T. (2024, December 30). Can we use quantum computers to test a radical consciousness theory? New Scientist.

Neven, H., & Koch, C. (2024, August 9). Experiments Prepare to Test Whether Consciousness Arises from Quantum Weirdness. Scientific American.

Neven, H., Read, P., & Rees, T. (2021). Do Robots powered by a Quantum Processor have the Freedom to swerve? arXiv:2104.11591.

Neven, H., Zalcman, A., Read, P., Kosik, K. S., van der Molen, T., Bouwmeester, D., Bodnia, E., Turin, L., & Koch, C. (2024). Testing the Conjecture That Quantum Processes Create Conscious Experience. Entropy, 26(6), 460.

Penrose, R. (1989). The Emperor's New Mind. Oxford University Press.

Treisman, A. (1996). The binding problem. Current Opinion in Neurobiology, 6(2), 171–178.

Zanardi, P., Tomka, M., & Venuti, L. C. (2018). Towards quantum integrated information theory. arXiv:1806.01421.