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Do Quantum Effects Play a Role in Consciousness? Roger Penrose's Theory

Paul graduated from Leicester University, having studied Philosophy of Science. UK born and raised, he now lives in Florida.

To discover how Roger Penrose uses quantum physics to show how human consciousness could be explained, please read on...

To discover how Roger Penrose uses quantum physics to show how human consciousness could be explained, please read on...

Understanding the nature of human consciousness has been a major issue for philosophers and scientists for many centuries. My own fascination with the topic began when I was introduced to the work of Rene Descartes during my Philosophy of Mind class at university.

The dominant contemporary scientific explanation is rooted in classical physics. Essentially, the theory is that consciousness occurs as a consequence of multiple complex brain activities combined with the way that the brain is organized.

However, there are those in recent years who've challenged this view, a prime example being Sir Roger Penrose, who believes that the prevailing explanation, based entirely on classical physics, is inadequate.

Penrose believes that consciousness is not a "computation" and that an alternative scientific theory is needed. Rather than the brain acting purely as a kind of independent, organic computation machine, Penrose argues that it could also be experiencing quantum effects, and this contributes to the phenomenon of consciousness.

In simple terms, it might be illustrative to consider a device such as an iPhone. Although, it may appear to be a contained device that's storing and processing internal data, it also streams information from elsewhere.

What Is Consciousness?

This question sounds like it should be straightforward, but in practice, consciousness has proved itself to be very difficult to define. In fact, there is no universally accepted definition.

Some people argue that consciousness is a composition of various elements, phenomena such as "awareness" and "intelligence", but these constituent concepts can be no easier to define than consciousness itself.

Defining consciousness is therefore a major part of the problem of solving the mystery of what consciousness is, and how it comes about.

Roger Penrose: "Consciousness Is Not a Computation"

Classical Physics Vs. The Penrose-Hameroff Theory of Quantum Consciousness

What follows is a simplified overview of the Penrose-Hammeroff theory of consciousness, as well as and some of criticism it has received.

It should be noted that the theory is controversial and is not generally accepted. While it shows how consciousness may work, it doesn't prove it.

Instead it attempts to demonstrate that an alternative theory, one that incorporates quantum effects and doesn't rely exclusively on classical physics, is possible.

Classical Physics: The Mainstream Scientific View of Consciousness

The dominant modern scientific view is that the human brain operates rather like a sophisticated organic computer and that consciousness occurs as a result of its complex but deterministic workings. In essence, consciousness is the summation of all the chemical and electrical interactions that go on in the human brain.

Consciousness is therefore a consequence of the actions and structure of the physical brain, a form of delusion or hallucination created in accordance with the classical laws of physics. In this explanation, consciousness is explainable, or at least potentially explainable, without any need for the involvement of quantum physics.

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Perhaps a key weakness of this approach is that it relies to a large degree on faith that classical physics will at some point in the future be able to explain exactly how and why consciousness comes about. Right now, it's essentially assumed that it occurs because of brain structure and activity.

The Penrose-Hameroff Theory of Quantum Consciousness

Roger Penrose believes that the prevailing scientific explanation fails to properly account for consciousness and therefore an alternative scientific theory is needed. He believes that quantum effects could contribute to a new way of interpreting consciousness.

Consciousness is not a computation

According to Roger Penrose, both subjective and objective observations demonstrate that consciousness is a quite different phenomenon to the "sophisticated machine" concept offered by classical physics.

Consciousness is "non-computational," according to Penrose: it's not a physical process that can be described by computation. It doesn't arise from the workings of a "Turing machine".

For Roger Penrose, the prevailing theory of consciousness, based purely on classical physics, is essentially too reductionist in its approach.

If consciousness was just matter and energy controlled by the classical laws of physics, then why does consciousness disappear when someone dies? The matter and energy are still there straight after death, but there is something different occurring. If consciousness was solely dependent on the physical matter and energy, it wouldn't vanish in that way.

The role of quantum effects in consciousness

Evolutionary biology has taken advantage of quantum effects and it can be seen in nature. For example: plants use quantum effects to turn sunlight into fuel, migratory birds use it to help with navigation, and even the human sense of smell may well rely on it, according to recent studies. It's reasonable to hypothesize that quantum effects might be involved with consciousness.

Penrose believes that there is a gap between the quantum system and the classical system of physics, and that this gap enables the idea that consciousness is experienced via the quantum mechanical effect.

Orch (Orchestrated objective reduction)

When Roger Penrose first posited his theory of quantum consciousness, he was unable to theorize how quantum effects might interact with the neurological physiology of the brain. It was only when he was contacted by Stephen Hammeroff that he was able to develop his theory more fully.

Hammeroff, who has a background in anesthesiology, was able to point to a potential biological facilitator for quantum consciousness: the fine structures in the brain known as microtubules.

Anesthesiology demonstrates that consciousness can be turned on and off. Through his work in this field, Stephen Hammeroff reached the conclusion that the microtubules are integral to this process and are therefore necessary for consciousness.

The science is complicated, but the essence of this idea is a that each molecule of a tubulin could potential operate as a quantum bit, or qubit. Conscious is the result of of the collapse of the superposed states of tubulin.

Quantum Mind: Is Quantum Physics Responsible for Consciousness and Free Will?

Criticisms of the Penrose-Hammeroff Theory

Penrose's theory has generally received a negative response from the scientific community. Perhaps the most scathing criticism has come from the Swedish-American physicist Max Tegmark: his analysis suggests that the brain is too wet and warm for the quantum effects proposed by Penrose and Hammeroff to occur. Quantum states in the brain would lose coherence too quickly, according to Tegmark.

It's also important to note that there is no experimental evidence that proves the quantum consciousness theory proposed by Penrose and Hammeroff, and even if quantum mechanical effects were to be shown to be involved with brain activity, that wouldn't necessarily mean that they were involved with consciousness.

Who Is Sir Roger Penrose?

Sir Roger Penrose is a British mathematician, mathematical physicist, philosopher of science and Nobel Laureate in Physics. He holds a number of academic positions, including being Emeritus Rouse Ball Professor of Mathematics at the University of Oxford, and an honorary fellow of St John's College, Cambridge.

If you've heard of Penrose before, it's most likely to be in connection with his work in the field of mathematical physics of general relativity and cosmology, particularly the work on black holes that he undertook with Steven Hawking, which won Penrose a Nobel Science Prize in 2020.

He first explored the relationship between quantum theory and consciousness in his seminal book, The Emperor's New Mind (1989). Here, he argued that the classical laws of physics are inadequate when it comes to explaining the phenomenon of consciousness and that it's therefore necessary to consider the role that quantum physics might play.

Who Is Stuart Hammeroff?

Stuart Hammeroff is an American anesthesiologist, a professor at the University of Arizona, and a key figure in the Science of Consciousness. His main contribution to the Penrose-Hammeroff theory is his contention that consciousness originates from quantum states in neural microtubules.

Hammeroff's relationship with Roger Penrose's work on consciousness goes back to the 1980s. One major gap in Penrose's theory was that he provided no appropriate physiological mechanism that could form the conduit between the quantum mechanical effect and the firing of neurons within the brain.

Stuart Hammeroff, with his background in Anesthesiology, was able to posit neural microtubules as the potential solution.

Sources and Further Reading

This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.

© 2022 Paul Goodman

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