MERLIN SCIENCE — Nuclear Spin Qubits in Neural Tissue: A Quantum Cognition Model — E8 Intelligence Research

We open with the finding in one clean sentence. Nuclear spin qubits, specifically phosphorus-31, in neural tissue are proposed as a physical substrate for quantum cognition, with constraints on coherence times and molecular structure that are specific enough to test. Here's the field context. For decades, the question of whether the brain performs quantum computation has been dismissed as either metaphor or category error. Fisher's proposal changes the stakes by grounding the idea in concrete chemistry and nuclear physics, not vague entanglement. He identifies a plausible qubit candidate—phosphorus-31—and a plausible carrier, the Posner molecule, with a symmetry that might protect coherence long enough to matter. Now the mechanism. The model runs on spin-1/2 nuclei with a gyromagnetic ratio near 17.2 MHz per tesla. Coherence must survive beyond a tenth of a millisecond, which Fisher calls the quantum window. The Posner molecule, with its six phosphate groups arranged octahedrally, pr Author: Andrew Stewart Caldin, Independent Researcher, UK. Part of the E8 Intelligence Research series. Platform: e8intelligence.com