Quantum Cognition: The possibility of processing with nuclear spins in the brain

By Matthew Fisher. 2015

243 citations recorded by the source corpus.

The possibility that quantum processing with nuclear spins might be operative in the brain is proposed and then explored. Phosphorus is identified as the unique biological element with a nuclear spin that can serve as a qubit for such putative quantum processing - a neural qubit - while the phosphate ion is the only possible qubit-transporter. We identify the "Posner molecule", $\text{Ca}_9 (\text{PO}_4)_6$, as the unique molecule that can protect the neural qubits on very long times and thereby serve as a (working) quantum-memory. A central requirement for quantum-processing is quantum entanglement. It is argued that the enzyme catalyzed chemical reaction which breaks a pyrophosphate ion into two phosphate ions can quantum entangle pairs of qubits. Posner molecules, formed by binding such phosphate pairs with extracellular calcium ions, will inherit the nuclear spin entanglement. A mechanism for transporting Posner molecules into presynaptic neurons during a "kiss and run" exocytosis, which releases neurotransmitters into the synaptic cleft, is proposed. Quantum measurements can occur when a pair of Posner molecules chemically bind and subsequently melt, releasing a shower of intra-cellular calcium ions that can trigger further neurotransmitter release and enhance the probability of post-synaptic neuron firing. Multiple entangled Posner molecules, triggering non-local quantum correlations of neuron firing rates, would provide the key mechanism for neural quantum processing. Implications, both in vitro and in vivo, are briefly mentioned.

Subfields: Artificial Intelligence, Cellular and Molecular Neuroscience, Spectroscopy

View Paper: https://www.semanticscholar.org/paper/96755222c7e2bc29db740061b01bb6a6f230a3af

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Citations in the corpus

Quantum superposition, entanglement, and state teleportation of a microorganism on an electromechanical oscillator (2015, background): “Phys Rev Lett 114:123602 [34] Jacques SL (2013) Optical properties of biological tissues: a review Phys Med Biol 58:R37 [35] Fisher MPA (2015) Quantum cognition: the possibility of processing with nuclear spins in the brain.”
Robust Encoding of a Qubit in a Molecule (2019, background): “Of particular interest are Z3-symmetric molecules (such as monomethoxides [26] or Posner molecules [124,125]), which are invariant under rotations by 120°.”
Measurement-protected quantum phases (2020, unknown): “fects being relevant in the brain [24, 25].”
Hierarchical consciousness: the Nested Observer Windows model (2024, background): “…exist at spatiotemporal scales relevant to cognition at more foundational level, e.g. the cytoskeleton (Pinotsis et al. 2023), the molecular scale (Fisher 2015), or at supervening levels, e.g. whole-brain structure (Pang et al. 2023), the electric field of the body (Klimesch 2013, 2018), or…”
A Quantum–Classical Model of Brain Dynamics (2023, background): “Nonetheless, it has been proposed to interpret brain processes as a form of quantum computing [20, 22, 23, 25, 26].”