IS QUANTUM PROCESSING OPERATIVE IN THE BRAIN?
by Matthew Fisher
Fisher's theory of quantum entanglement in the brain starts with the chemical compound pyrophosphate.
Known to be essential for cellular function, pyrophosphate is made of two bonded phosphates, each made up of phosphorus (which has a nuclear spin of ½) and oxygen (which has a spin of zero).
When pyrophosphate is broken down by enzymes, the bonded pair of phosphate ions separates.
Pairs of spin-½ particles can combine in one of four ways. Three combinations lead to a total spin of one, and these are called triplet states. The fourth leads to a spin of zero, or a "singlet state," which is a special state of entanglement often referred to as the currency of quantum computing.
The enzyme catalysis of pyrophosphate occurs more often, and possibly only, if the bonded phosphate ions are in a singlet state. These entangled ions could then be "taken up" by nanometre-diameter-sized Posner molecules. Made up of six phosphate ions bound to nine calcium ions, Posner molecules have been identified in simulated body fluid and are thought to be present in the body.
The other ingredients in Posner molecules – calcium and oxygen – do not have a nuclear spin, and the small molecules are very spherical, thus are expected to tumble rapidly in water. This means the quantum entanglement of the phosphate ions is expected to be highly protected from its environment, and could remain coherent for a day or much longer.
With Posner molecules serving as a "qubit memory," the end result could lead to non-local quantum correlations – what Einstein called "spooky action at a distance" – in neurotransmitter release and postsynaptic firing across multiple neurons. This is what Fisher calls quantum cognition.
Neural qubits: Quantum cognition based on synaptic nuclear spins
August 27, 2015 by John Hewitt report
Can Quantum Physics Explain Consciousness?
A new approach to a once far fetched theory is making it plausible that the brain functions like a quantum computer.
by JENNIFER OUELLETTE NOV 7, 2016
|From Atlantic, Nov-2016|
Quantum Cognition: The possibility of processing with nuclear spins in the brain
Matthew P. A. Fisher
(Submitted on 19 Aug 2015 (v1), last revised 29 Aug 2015 (this version, v2))
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", Ca9(PO4)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.