When it comes to the human brain, its functions are as mysterious as they are essential.
The brain is often referred to as the body’s “computer.” In the Department of Physics and Astronomy, where world-class quantum research is taking place every day, researchers are taking that analogy one step further with a potentially groundbreaking theory about the brain’s communication.
Christoph Simon specializes in quantum physics, an enigmatic field not commonly associated with biology or neuroscience. Together with a team of researchers from the University of Calgary and the University of Alberta, Simon has recently published a paper in Nature’s Scientific Reports proposing that the brain may use elementary particles of light to communicate across the cable-like axons that connect its nerve cells, or neurons; in essence, the theory suggests the existence of a fibre optic network in the brain.
Simon had long been interested in learning about how the brain functions, but was uncertain how to blend that interest with his background in quantum physics. He found an entry point when learning about biophotons through a conversation with University of Alberta researcher and article co-author Jack Tuszynski. “Biophotons are photons that are produced by cells through normal metabolism, particularly in the brain. Photons are the fundamental particles of light,” Simon explains.
Brain’s communication system could mirror fibre optic network structure, researchers say
“It’s clear to everyone that the brain uses electrical signals and this is how messages are sent and received through the body’s nervous system,” he says.
“But we know that there are also photons present in the brain, and photons are really good for sending signals. It would seem natural for evolution to have found that as well.”
Simon says that the brain’s structure is similar to that of a fibre optic network, and has the potential to function as such. Using fibre optic cables, photons can be used for communication purposes across large distances. Messages inside the brain would, of course, be sent over much shorter distances.
“We already know, from our existing technology, what needs to be in place to make cables for photons,” tells Simon, who says that the refractive index of those cable fibres needs to be higher than that of its surrounding environment, like air or water, for the light to stay inside the cable. He compares this to the brain’s structure; the axons in the brain, in this theory, act as the “cables” that transmit light from one cell to another. The myelin sheaths that protect the axons help to keep the photons inside.
Simon and his colleagues developed a sophisticated mathematical model for testing whether axons could indeed, physically conduct light. They concluded that it is a serious possibility. However, their idea still has to be tested experimentally.
If Simon’s team’s theory proves to be true, and the axons and neurons of the brain constitute a light communication system, “it would be a whole new perspective on the brain,” he says.
Quantum laws may unlock mystery of how brain forms consciousness
Earlier this year, UCalgary researcher Wolfgang Tittel used Calgary’s existing fibre optic network to demonstrate that photons excel at transporting not only ordinary information, but also quantum information.
If the brain were also using photons to transport quantum information, it would be imaginable that some of the laws of quantum physics could apply to brain function and processing.
Quantum physics allows information to be sent and manipulated in ways that are not possible using rules based on the classical laws of nature (like teleportation). “My colleagues and I think about how to make quantum computers, which are vastly more powerful than regular computers,” says Simon. “If our theory is true, that means that the brain might also function like a quantum computer. It could be that some of the mysterious features of quantum physics are responsible for some of the mysterious features of the brain.”
If so, Simon speculates it might hold the clue to how the brain produces the state of consciousness, another question whose solution has long evaded researchers.
While other experiments have produced some indirect evidence that supports the theory, Simon points out that many more years of research and experiments are required before it can be confirmed. He is discussing the next steps with other scientists to put together a multidisciplinary team.