Quantum-Inspired and Non-Classical Approaches to Consciousness: Models, Evidence and Constraints.
Brain Sci March 31, 2026 Oscar Arias-Carrión, Emmanuel Ortega-Robles, Elías Manjarrez
Consciousness poses a puzzle: unified experience arises from distributed brain activity. Classical neuroscience explains synaptic and network mechanisms, but debates continue over whether quantum principles are needed. This review examines quantum ideas in two ways: as mathematical models for context-dependent cognition and as hypotheses about real quantum states in the brain. It surveys evidence from MRI signals, learning models, and proposed neural substrates like microtubules and nuclear spins. No study has yet demonstrated entanglement or long-lived coherence in neural tissue under standard quantum criteria. Replication is limited, and classical dynamics can mimic quantum signatures. The key question is whether brain dynamics exceed classical models. Progress requires precise tests to distinguish quantum correlations from classical complexity.