Limits of the quantum cognition hypothesis: 31P singlet order lifetimes of pyrophosphate from experiment and simulation

A proposal of quantum cognition advances the hypothesis that quantum entanglement between 31P nuclei could serve as a means of information storage in the brain. Testing this hypothesis requires an understanding of how long-lived these quantum effects may be. We used NMR spectroscopy and molecular dynamics simulations to study the mechanisms that limit these quantum processes in 18O-enriched molecules of pyrophosphate, the simplest biomolecule that can sustain quantum-entangled 31P nuclear spin singlet states. We confirmed that chemical shift anisotropy limits the singlet magnetization order lifetimes in high magnetic fields, and we discovered that rapid rotation of the phosphate groups limits the lifetime in low magnetic fields. These findings represent an important starting point in studying whether quantum cognition can be a true biological phenomenon.