Photon entanglement could explain rapid brain signals that drive consciousness

Understanding the nature of consciousness is one of the most difficult problems in science. Some scientists have suggested that quantum mechanics, and in particular quantum entanglement, is the key to elucidating this phenomenon.

A Chinese research team has shown that many entangled photons can be generated inside the myelin sheath that covers nerve fibers. This could explain the rapid communication between neurons, which was previously thought to occur at a speed below the speed of sound, too slow to explain how neuronal synchronization occurs.

The article is published in the journal Physical examination E.

“If the power of evolution were to seek practical action at a distance, quantum entanglement would be an ideal candidate for this role,” Yong-Cong Chen said in a statement to Phys.org. Chen is a professor at the Shanghai Center for Quantitative Life Sciences and the Department of Physics at Shanghai University.

The brain communicates with itself by sending electrical signals called synapses between neurons, which are the main components of nervous tissue. It is the synchronized activity of millions of neurons that underlies consciousness (among other brain functions). But how this precise synchronization occurs is unknown.

The connections between neurons are called axons (long, wire-like structures) and are covered with a coating (“sheath”) made of myelin, a white tissue made of lipids.

Composed of several hundred layers, myelin insulates axons, shapes them, and provides them with energy. (In reality, a series of such sheaths extend the length of the axon. The myelin sheath is typically about 100 microns long, with spaces of 1 to 2 microns between them.) Recent evidence suggests that myelin also plays an important role in promoting synchronization between neurons.

But the speed at which signals propagate along axons is slower than that of sound, sometimes much slower – too slow to create the millions of neural synchronizations that underlie all the amazing things the brain can do.

To address this problem, Chen and his colleagues investigated whether there might be photons entangled in this axon-myelin system that could, through the magic of quantum entanglement, communicate instantaneously across the distances involved.

A tricarboxylic acid cycle releases the energy stored in nutrients, with a cascade of infrared photons released during the cycling process. These photons couple to the vibrations of carbon-hydrogen (CH) bonds in lipid molecules and excite them to a higher vibrational energy state. When the bond then transitions to a lower vibrational energy state, it releases a cascade of photons.

The Chinese group applied cavity quantum electrohydrodynamics to a perfect cylinder surrounded by myelin, reasonably assuming that the outer wall of the myelin sheath is a perfectly cylindrical conductive wall.

Using quantum mechanical techniques, they quantized the electromagnetic fields and the electric field inside the cavity, as well as the photons – that is, they treated them all as quantum objects – and then, with a few simplifying assumptions, they solved the resulting equations.

They thus obtained the wave function of the system of two photons interacting with matter inside the cavity. They then calculated the degree of entanglement of the photons by determining their quantum entropy, a measure of disorder, using an extension of classical entropy developed by the scientific polymath John von Neumann.

“We showed that two photons can indeed have a higher entanglement rate under certain circumstances,” Chen said in the statement.

The conductive wall limits the modes of electromagnetic waves that can exist inside the cylinder, making it an electromagnetic cavity that retains most of its energy. These modes are different from the continuous electromagnetic waves (“light”) that exist in free space.

It is these discrete modes that result in the frequent production of highly entangled photons in the myelin cavity, the production rate of which can be significantly enhanced compared to two unentangled photons.

Entanglement means that the two-photon state is not a classical combination of two photon states. Instead, measuring or interacting with one of the photons instantly affects the same property of the second photon, regardless of its distance.

Entanglement has been demonstrated for a system whose members are more than 1,000 km apart. Nothing like this exists in classical physics; it is a purely quantum phenomenon. In this case, entanglement would open up the possibility of much faster signaling along the sections of myelin that surround segments of the axon’s length.

According to the authors, it is possible that the photon entanglement turns into entanglement along the neuron’s potassium ion channels. If so, opening and closing one channel could affect the performance of another channel located elsewhere.

Chen told Phys.org that their result is a combination of two phenomena that exist but remain largely mysterious: consciousness (let alone quantum consciousness) and quantum entanglement.

“We won’t say there is a direct link. At this early stage, our main goal is to identify possible mechanisms of neuronal synchronization, which affects many neurobiological processes. Through this work, we hope to gain a better understanding.”

© 2024 Science X Network