Century's Top 'Headcanon'? A Genius Theory That Unlocked the Secret of Consciousness?

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What is consciousness? A genius physicist tackles the question of the century

Human consciousness is one of the biggest and most difficult problems facing modern science. As Descartes famously said, “I think, therefore I am.”, We take our own existence and thoughts for granted, yet no one can clearly explain where and how the subjective experience of “I”—that is, consciousness—arises from the physical workings of the brain. Fundamentally, biologists believe that consciousness is created from the connectivity of neurons. How do the electrical signals exchanged between neurons create such a rich variety of emotions, thoughts, and the feeling of "self"?

In response to this question, most neuroscientists explain consciousness as an emergent phenomenon that arises from the brain’s complex information processing. The idea is that consciousness spontaneously appears when a network of countless neurons reaches a certain level of complexity. However, Roger Penrose, a mathematician and the 2020 Nobel laureate in Physics, was not satisfied with this explanation. Originally a physicist specializing in quantum mechanics, he collaborated with an anesthesiologist, sharing diverse literature and experiences to unravel the secret of consciousness, and soon explained its origin through quantum mechanics.

Quantum mechanics meets the brain: birth of the Orch OR theory

In the 1990s, Penrose joined forces with anesthesiologist and consciousness researcher Stuart Hameroff to propose a bold and revolutionary hypothesis: the ‘Orchestrated Objective Reduction (Orch OR)’ theory.

The core claim of this theory is as follows:

“Consciousness is the result of a quantum process occurring in a biomolecule called the 'microtubule' inside brain neurons.”

What on earth does that mean? When we talk about consciousness, we typically think the connections between nerve cells, called synapses, are crucial. As the image below shows, if a synapse is the connection between neurons, a microtubule is the cytoskeleton that exists within a cell. You could think of it as our human “bones.” Wait a minute… the skeleton of a brain cell… creates consciousness?

Microtubules are biomolecules where quantum computation occurs, and this is how consciousness emerges!

Penrose claimed the microtubule as a biomolecule capable of exhibiting quantum phenomena. But what is the microtubule exactly? When a small piece of biomolecule called tubulin stacks up to form a large cylindrical structure, that is a microtubule. It’s a fundamental biological structure found not just in nerve cells but in all cells. Penrose claims that the cylindrical structure it forms is key to quantum interactions.

He said that The cylindrical structure of the microtubule excellently isolates the inside from the outside, creating an optimal environment for quantum phenomena to occur. What’s important in the quantum world are quantum entanglement and superposition. A tricky condition for quantum phenomena to occur is the absence of interaction with other molecules, but the cellular environment is typically fraught with all sorts of interactions. A cell is a meticulously packaged space of constantly colliding water molecules, various proteins, minerals, and small molecules. In such an environment, a quantum state cannot be maintained. Quantum physicists describe such a complex and chaotic system as “hot and noisy.” (In fact, body temperature is far too hot from a quantum mechanics perspective.)

Thus, while it seems unlikely for quantum phenomena to occur inside the “hot” cell, Penrose argues that the interior of the microtubule’s cylindrical structure is so isolated that they can. He posits that quantum information continuously accumulates in this microtubule. When this accumulated quantum information reaches a certain level, it triggers a quantum collapse all at once, and when it resolves into a single phenomenon, consciousness emerges, as if from a calculation performed by a quantum computer.

This process was particularly inspired by the observation that anesthetic drug make a interaction with the microtubule. For this reason, he argues that during synaptic transmission neurotransmitters control microtubule, so that heedful control makes a variety of calculations and is “Orchestrated” according to some regulatory mechanism. This is the meaning of “Orch” in the Orch OR theory.

The moment of consciousness: what does “objective reduction” mean?

What does it mean to be “objectively reduced”? This is called Objective Reduction (OR), and it means that a quantum collapse occurs without any external intervention. It is generally known that a quantum phenomenon collapses when it interacts with another molecule, but Penrose sees it differently. He believes it can collapse spontaneously without any interaction. Thinking about microtubules, as explained earlier, a quantum superposition state accumulates in the microtubule, and he believes that when it reaches a certain level, it naturally leads to a quantum collapse. This is what is meant by being “objectively reduced.” Combined, “Orch OR” stands for “Orchestrated Objective Reduction.”

The frequency of consciousness: quantum build-up and collapse seen in EEG—and anesthesia

EEG (Electroencephalography) is a technology that allows for real-time monitoring of the electrical currents generated by the neurons that make up the brain. Penrose used this to check how signals in the brain operate over time. Seeing this, he thought that the patterns appearing as frequencies were evidence of the moments of quantum accumulation and collapse.

And it’s not just EEG technology. Anesthesiologist Stuart Hameroff had been studying the working principles of anesthetics. He claimed that various types of anesthetics share a common feature: they target a specific location (a hydrophobic pocket) inside the tubulin proteins of microtubules. In other words, he believed that anesthetics wedge into these tubulin proteins and interfere with quantum computation, causing consciousness to momentarily switch off.

Remaining questions: limits and challenges of the theory

It’s a very intriguing and fun theory, and some papers even claim that quantum phenomena have been observed to be transmitted over nanometer distances along microtubules.¹ However, Let just think about some critical limitations as follows.

First, every cell has a cytoskeleton.

Microtubules are something that every single cell in the entire body has. The idea that only neurons can derive information from them is a bit hard to accept. In response, Penrose says that brain nerve cells have a different special arrangement and stability compared to the microtubules of other cells, and that they are different because they form a network through Gap junctions. However, most connective tissues have Gap junctions, and in fact, it is epithelial or endothelial cells that have the most robust Gap junctions. They even have much more complex microtubule structures. If we accept his argument, then the skin could be seen as having even better conditions for consciousness to arise.

Second, too many biomolecules interact with microtubules.

A prime example is the Motor protein. This fellow is well-known as a protein that moves various biomolecules to designated locations, and it’s famous for literally “walking.” The highway this fellow travels on is none other than the tubulin protein. If quantum information accumulates on tubulin proteins, then why isn’t the quantum information collapsed by molecules like this Motor protein that are in direct contact? Quantum states are extremely delicate and easily collapse upon external contact. Yet, giant protein trucks are constantly rumbling along the quantum track that is the microtubule, so how can the microtubule maintain a serene quantum state?

Third, the cylinder was actually an open system, not a closed one.

The claim is that because the target of anesthetics is inside the cylinder, a quantum state can be maintained, unlike the external environment. However, paradoxically, if an anesthetic introduced from the outside targeted the inside of the cylinder and switched off consciousness, then that means that all molecules of a similar size and state to the anesthetic can invade the inside of the cylinder. Ironically, the logic presented as a defense contains a fatal flaw. In other words, it means that all other molecules similar to anesthetics can also invade that pocket and disturb the quantum state.

Conclusion: so what is consciousness, really?

The Orch OR theory is not yet a complete theory. It is still in the stage of verifying and confirming many hypotheses and intermediate logics.

Nevertheless, what makes it remarkable is that it marks a starting point for consciousness. Simply saying that consciousness is created when synapses become complex is just a roundabout way of saying that the causal relationship cannot be explained scientifically. It only describes the phenomenon but fails to explain fundamentally why? or how? it is possible.

The Orch OR theory tries to explain consciousness somehow by mixing microtubules and quantum collapse. Not only is the interdisciplinary knowledge, which seems to be at odds with each other, very excellent, but also talking about the fundamental explanation is the very attitude of science itself.

Whether the answer is right or wrong, this intellectual journey of knocking on the door of the most fundamental questions deserves to be applauded.

References

• Hameroff, Stuart, and Roger Penrose. “Consciousness in the Universe: A Review of the ‘Orch OR’ Theory.” Physics of Life Reviews 11, no. 1 (2014): 39–78. https://doi.org/10.1016/j.plrev.2013.08.002.