Roger Penrose on Consciousness as Non-Computational and Orchestrated Objective Reduction

Roger Penrose argues that consciousness is fundamentally not a computation, but rather a non-computational physical process. This perspective contrasts sharply with the prevailing view in artificial intelligence, which often posits that intelligence and consciousness can arise from complex computational systems. Penrose's skepticism, fueled by early discussions with AI pioneers like Edward Fredkin and Marvin Minsky, led him to explore alternative explanations rooted in fundamental physics, culminating in his book "The Emperor's New Mind" and the subsequent development of the Orchestrated Objective Reduction (Orch OR) model in collaboration with Stuart Hameroff.

The Orch OR model proposes that consciousness originates at the quantum level within neurons, specifically involving structures called microtubules. Penrose initially sought a biological substrate capable of preserving quantum coherence, a state crucial for non-computational processes. Stuart Hameroff introduced him to microtubules, which are symmetrical structures found in nearly all cells, including neurons. Hameroff's research on general anesthetics, which reversibly turn consciousness off, suggests that these gases directly affect microtubules, providing a potential biological link for the Orch OR hypothesis. The symmetrical nature of microtubules is posited to be key for maintaining the delicate quantum states necessary for consciousness.

Penrose emphasizes that his theory goes beyond conventional quantum mechanics, which, when described by the Schrödinger equation, is still computable. He argues that true non-computability arises from the "state reduction" or "collapse of the wavefunction" – the process by which a quantum superposition resolves into a single definite state. He highlights that prominent physicists like Einstein, Schrödinger, and Dirac recognized the incompleteness of quantum mechanics in explaining this phenomenon. Penrose proposes that this state reduction is a non-computational process influenced by gravity, a view that distinguishes his concept of quantum gravity from standard approaches that merely quantize gravity within existing quantum frameworks.

The Orch OR model suggests that these non-computational state reductions give rise to "proto-conscious" elements, which are then "orchestrated" by the brain into genuine conscious experience. While the "objective reduction" (OR) part is grounded in his modified quantum gravity theory, the "orchestration" (Orch) aspect remains more mysterious. Experimental efforts are underway to test aspects of this theory, including Jeremy Stowe's work on demonstrating gravitational effects on quantum mechanics and Hameroff's ongoing research into how anesthetics interact with microtubules. Penrose categorizes current theories of consciousness as not even reaching the "tentative" stage, underscoring the profound challenges and the minority status of non-computational approaches, while also distinguishing between understanding, intelligence, and awareness, with understanding being central to his inquiry.

"whatever consciousness is it's not a computation"

"I thought well know where you're coming from but I just don't believe you there's something missing that's it's not that"

"I'm trying to find out how it is that nerve signals could possibly preserve quantum coherence"

"Stuart Hameroff... said I think you're missing something you don't know about microtubules do you"

"these little tubes which inhabit pretty well ourselves... were much better at preserving a quantum state quantum coherence"

"it's not just quantum mechanics people say oh we know quantum systems and biological structures know we'll use starting to see that some basic biological systems does depend on quantum"

"conventional quantum mechanics if you're just following the Schrodinger equation that's still computable so you've got to go beyond that"

"Einstein at least three of the greatest physicists of 20th century who were very fundamental in developing quantum mechanics Einstein one of them Schrodinger another Dirac another... says quantum mechanics is a provisional theory we need something which explains the collapse of a wavefunction"

"my view is almost the exact opposite of that it's the state reduces itself in some way which some non computational way which we don't understand"

"proto consciousness is roughly speaking the building block out of which actual consciousness is constructed"

"I like to say could you say of an entity that is actually intelligent if it doesn't have the quality of understanding"