Monte Carlo simulation of quantum Zeno effect in the brain

TL;DR

This study uses Monte Carlo simulations to evaluate the feasibility of the quantum Zeno effect in the brain, finding it unlikely due to environmental decoherence, but suggests potential in decoherence-free subspaces.

Contribution

It models brain quantum dynamics with simulations and proves a theorem showing the limitations of the quantum Zeno effect under decoherence.

Findings

Quantum Zeno effect breaks down beyond brain decoherence time.

Local projections cannot reduce brain von Neumann entropy.

Stapp's model is physically implausible without decoherence-free subspaces.

Abstract

Environmental decoherence appears to be the biggest obstacle for successful construction of quantum mind theories. Nevertheless, the quantum physicist Henry Stapp promoted the view that the mind could utilize quantum Zeno effect to influence brain dynamics and that the efficacy of such mental efforts would not be undermined by environmental decoherence of the brain. To address the physical plausibility of Stapp's claim, we modeled the brain using quantum tunneling of an electron in a multiple-well structure such as the voltage sensor in neuronal ion channels and performed Monte Carlo simulations of quantum Zeno effect exerted by the mind upon the brain in the presence or absence of environmental decoherence. The simulations unambiguously showed that the quantum Zeno effect breaks down for timescales greater than the brain decoherence time. To generalize the Monte Carlo simulation results for any n-level quantum system, we further analyzed the change of brain entropy due to the mind probing actions and proved a theorem according to which local projections cannot decrease the von Neumann entropy of the unconditional brain density matrix. The latter theorem establishes that Stapp's model is physically implausible but leaves a door open for future development of quantum mind theories provided the brain has a decoherence-free subspace.