For decades, the human brain has been compared to a computer. But this metaphor, as practical as it may be, risks underestimating what our organ thinking actually accomplishes. Ultra-effective, flexible, capable of learning, imagining or creating, the brain is much more than a network of mechanical neurons. What if, rather than being inspired by classic computer technology, you had to turn to another area, even more mysterious: quantum physics?
It is the daring idea that a new study from the University of Shanghai brings up to date, based on an almost magical phenomenon: quantum entanglement.
A quantum brain? An old idea always controversial
In the 1990s, the physicist Roger Penrose and the anesthesiologist Stuart Hameroff had already formulated an iconoclastic hypothesis: human consciousness would be the product of quantum phenomena inside neurons. Their model, called Orch-Or (orchestrated objective reduction), attracted the wrath of a large part of the scientific community, for lack of concrete evidence. But he also opened a breach in our understanding of the brain: what if certain mental processes escaped the simple laws of classical physics?
Because despite decades of research in neuroscience, a mystery remains: how does the brain manage to synchronize millions of neurons to produce a unified consciousness? This orchestration remains difficult to explain by known electrochemical mechanisms alone.
Entanglement, or the “magic” of quantum physics
Quantum entanglement designates a strange, but very real phenomenon, in which two particles (like photons) become linked in such a way that the state of one instantly depends on the other, even miles away. Albert Einstein himself found this “too bizarre” to be true, qualifying this invisible link as “strange action at a distance”. However, entanglement is now demonstrated and used in certain secure communication protocols.
The Chinese study, published in
Physical Review Esuggests that the human brain could exploit this phenomenon. The researchers modeled the effect of certain infrared vibrations in myelin – this fatty sheath which envelops the axons of the neurons. According to their calculations, this cylindrical structure could constitute an ideal environment to generate pairs of intrigued photons, capable of moving to different regions of the brain.
A new form of neural communication?
For the authors, this hypothesis could shed light on the mystery of neuronal synchronization. If entanglement allows an almost instantaneous form of communication between distant brain regions, then the brain would have a real natural quantum network, much faster than conventional electrical signals.
They even evoke the idea that these entangled photons could constitute a “quantum communication resource” within the nervous system. In other words: the brain could use certain laws of the subatomic world to optimize its transmission of information, even generate complex phenomena such as consciousness.
A more in -depth examination of myelin cylinders and their location along the neuron axon. Credits: Liu et al., Physical Review E, 2024
Science ou science-fiction
?
Let’s be clear: these results remain purely theoretical. No direct experimental evidence of this mechanism was observed in a living brain. The challenge is enormous: it would be a question of detecting photograms entangled in a warm, humid and chaotic biological environment. In other words, exactly what quantum systems hate.
But that does not prevent researchers from believing it. As one of the co-authors underlines, Yong-Cong Chen, if the evolution was looking for a means of establishing rapid and precise coordination between neurons, quantum entanglement would be a fascinating candidate.
A border between two worlds
Even if this hypothesis remains speculative, it feeds an essential debate: how far can biology meet quantum physics? Other areas – such as photosynthesis or navigation in certain birds – have already shown that quantum mechanisms could intervene in biological processes.
So why not the brain? Perhaps we will one day discover that what we call today “consciousness” is the fruit of a subtle tangle between chemistry, electricity, and unsuspected quantum phenomena. In the meantime, science continues to test the limits of the imaginable – and that is all its power.
