Quantum Entanglement May Help Explain Consciousness in the Brain

A quiet symphony is unfolding in your brain at this very moment, as neural pathways co-ordinate in an electromagnetic chorus believed to produce consciousness.

Yet the way different circuits across the brain bring their firing into step remains a persistent mystery. Some theorists believe the answer could involve quantum entanglement.

Quantum entanglement and consciousness

This is a daring suggestion, particularly as quantum effects usually fade into insignificance beyond the scale of atoms and molecules. However, several recent discoveries are prompting researchers to set aside their scepticism and reassess whether quantum chemistry could, after all, operate within our minds.

In a newly published paper, physicists Zefei Liu and Yong-Cong Chen of Shanghai University, alongside biomedical engineer Ping Ao of Sichuan University in China, describe how entangled photons released by carbon-hydrogen bonds in nerve-cell insulation might synchronise brain activity.

Their work follows only months after the identification of another quantum effect, superradiance, in cellular structures. That finding has renewed attention on a highly speculative theory of consciousness: the Penrose-Hameroff 'orchestrated-objective reduction' model.

Developed by the esteemed physicist Roger Penrose and American anaesthetist Stuart Hameroff, the model proposes that networks of cytoskeletal tubules, which provide cells with structural support, act in our neurons as a form of quantum computer that somehow influences thought.

Why quantum physics is considered for the brain

The attraction of using quantum physics to account for consciousness is easy to understand. Both possess a certain 'weirdness' – an elusive combination of predictability and randomness.

There is also the longstanding question of which crucial observation converts quantum uncertainty into a definite classical measurement. Might a quantum event in the brain be connected to the collapse of a probability wave?

However, weird plus weird does not amount to scientific fact, regardless of how difficult either idea is to comprehend. The brain may not function as a classical computer, but adding quantum magic is unlikely to produce a complete theory.

Scientists have another strong reason to keep their sceptical hats firmly in place regarding quantum theories of consciousness. Biology's messy currents have traditionally been viewed as too chaotic, too noisy and too 'big' for quantum mechanics to arise in any meaningful form.

That assumption may need revisiting, especially if experiments confirm the prediction made by Liu, Chen and Ao.

Myelin and entangled photons in the brain

The researchers suggest that myelin, the fatty coating surrounding a nerve cell's axon 'tail', could potentially act as an appropriate cylindrical cavity. It might amplify infrared photons generated elsewhere in the cell, leading carbon-hydrogen bonds to occasionally emit pairs of photons whose properties are strongly correlated.

As these entangled photons move through the ionic currents of the brain's biochemistry, they could potentially create correlations between processes central to the organ's capacity for synchronisation.

Naturally, the word 'might' is carrying an enormous amount of weight here. Although many empirical findings support elements of the hypothesis, evidence that entangled photons affect large-scale biological processes is currently restricted to photosynthesis.

That said, quantum biology has some animal precedents. Growing evidence indicates that the hazy superposition states of electron spins in proteins known as cryptochromes can be altered by magnetic fields, which may help account for long-distance navigation in certain animals.

We are still far from showing that anything beyond classical chemistry occurs inside our heads, let alone confidently claiming that the brain's symphonies are brought together by a quantum composer.

Even so, it may be time to pause objections to the possibility that quantum phenomena influence at least some of the brain's fundamental functions.

This research was published in Physical Review E.