In a slice of brain tissue, two neurons fire and fall silent. Sodium floods in, potassium rushes out, the membrane voltage collapses, and heat dumps into the surrounding fluid. By every measurement a laboratory can make on the two cells, voltage, ion concentration, and temperature, they are now in the same condition.
One of them will be ready to fire again before the other.
Neuroscience has good explanations for that. A channel here, a gradient there, a pump running a little hot. But Onur Pusuluk, a physicist at Kadir Has University in Istanbul, thinks there may be something else going on, something no instrument in the room can detect: something related to the quantum nature of consciousness.
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Understanding the Quantum Brain
An arXiv pre-print paper posted in April 2026 argues that the difference between two apparently identical neurons is stored in a hidden arrangement, a set of relationships among the cell's parts that no single measurement can capture. Pusuluk argues that this arrangement is the residue of quantum mechanics doing its work and then dying. And he argues that chasing it would settle a 30-year fight about the quantum brain by discarding the question that started it.
The claim rests on a piece of thermodynamics that has nothing to do with brains.
Take two containers of water at the same temperature. Same pressure, same dissolved gas, same everything a lab sheet has a line for. By every measurement available, the two are in the same condition. Recent theoretical work, most of it Pusuluk's own, argues they can still freeze at different rates.
This is possible because a thermometer reads one spot. So does a pressure gauge. Every number on that lab sheet comes from a single place, one region at a time, and none of them can capture the way the state of one region is bound up with the state of another. Those relationships live between the parts and inside none of them. They help decide how fast the whole thing settles.
Two systems can be identical at every point of inspection and still be different systems. That is what Pusuluk suspects about the two neurons, and that by digging deeper into these differences, we may reveal something extraordinary.
Quantum Coherence Survives In The Brain
He is not the first physicist to go looking for quantum effects in the brain.
Roger Penrose and Stuart Hameroff proposed in the 1990s that consciousness arises from quantum processes inside neurons, in tiny structural filaments called microtubules. Max Tegmark killed the idea in 2000 with a calculation. A quantum state inside a brain, which is warm, wet, and full of noise, survives for about a ten-trillionth of a second. Neurons work on millisecond timescales, a trillion times slower. Whatever quantum weirdness flickers to life in a skull dies long before it could matter.
Pusuluk does not argue that quantum coherence survives in the brain. He agrees that it dies fast, exactly as Tegmark said. He argues that dying is the interesting part.
A quantum correlation is a relationship between two particles, two protons sharing a hydrogen bond, say. When a warm, noisy cell tears that relationship apart, it leaves nothing behind. It leaves a coarser relationship, an ordinary classical correlation, an arrangement no thermometer can see, still shaping how fast the cell settles.
So the warmth is not only wrecking quantum states. Thermal contact with the surroundings might be the very thing that converts a fragile quantum relationship into a sturdier classical one that outlasts it. Three decades of treating heat as the enemy of the quantum brain, and here is a physicist suggesting it is what puts the arrangement within the cell's reach.
Where in a neuron would this happen? Pusuluk gestures toward ion channels, the protein pores that allow potassium ions to pass single file across a cell membrane. The hydrogen bonds thread the water inside a cell. At the phosphate groups that carry nuclear spins, nobody has bothered to count.
Further Study Is Needed
Nobody has tested any of this. The paper is a preprint, not yet peer-reviewed, containing no data or experiments. It is a single-author work that gathers a decade of his scattered papers into a single framework, and the central result he relies on has not been published either.
Pusuluk said as much himself. He calls the neuron proposal a scenario rather than a mechanism. He concedes that his treatment of ion channels lacks the accounting that would make it rigorous. On what comes next, he believes the field needs sharper theory before it needs better experiments, which is a careful way of saying he cannot yet predict what an experiment would find.
So the two neurons in the tissue slice recover at different rates, as they always have, and the channel, the gradient, and the overworked pump account for it, as they always have.
Somebody could go and measure it. Take a population of neurons, drive them all to the same state, and time how long each one takes to come back. That spread already sits in the literature, filed under “noise.” Pusuluk's bet is that some of it is far more interesting.
Read More: Where Does Conscious Experience Come From? We May Be Getting Closer to an Answer
Article Sources
Our writers at Discovermagazine.com use peer-reviewed studies and high-quality sources for our articles, and our editors review for scientific accuracy and editorial standards. Review the sources used below for this article:
- This article references information from a pre-print study published in arXiv: The physical basis of information flow in neural matter: a thermocoherent perspective on cognitive dynamics
- This article references information from a study published in The Royal Society: Proton tunnelling in hydrogen bonds and its implications in an induced-fit model of enzyme catalysis
- This article references information from a study published in Physics of Life Reviews: Consciousness in the universe: A review of the ‘Orch OR’ theory
- This article references information from a study published in Physical Review E: Importance of quantum decoherence in brain processes
