Season 17, Episode 9: Is Consciousness Quantum?

Hey StarTalkians! Season 17, Episode 9 saw Neil, Chuck, Gary O’ Reilly and guest Charles Liu sit down to answer a grab-bag of “Cosmic Queries.”

The episode title, and the bulk of the discussion, was about “quantum consciousness”:

The Problem With Uploading Your Consciousness | Cosmic Queries #105

But the discussion was long and a little meandering. I was left wondering: why exactly would you think this anyway? Is it really just what Neil said – that it’d be nice if one extremely complicated thing explained another – or is there more to it than that?

The Multiverse of Theories

The basic idea takes many forms, ranging from “grand unified theories” that also (somehow) explain consciousness to hyper-specific quantum processes going on in the brain.

But Roger Penrose’s idea – mentioned briefly in the podcast – is the most interesting and fleshed-out.

Orch OR Quantum Consciousness

Nobel Prize winner Roger Penrose and Stuart Hameroff’s idea, Orch OR (Consciousness in the universe ), basically imagines the human brain as a quantum computer, of sorts.

It centres on the proposed phenomenon of “objective reduction” (aka OR). This is a take on the “wavefunction collapse” problem, which posits that unlike in the Copenhagen Interpretation (Season 17, Episode 4: The Copenhagen Interpretation Explained | StarTalk | Project Credo ), the process of wavefunction collapse is very real. The superposition is objectively reduced to one possibility.

Wavefunctions would just spontaneously collapse, in the same way a radioactive atom spontaneously decays. In fact, they propose a “half life”-like measure of when this usually happens.

Orchestrated or “Orch” OR brings consciousness into this. They propose that these collapse events take place in your neurons, specifically in microtubules. When quantum entanglement in your neurons decays via OR, this creates a “proto-conscious” event – a fragment of subjective consciousness, like a passing thought or sensation.

It’s orchestrated because in the theory, your brain evolved to do this on purpose, creating a kind of quantum computer to process this data.

The Problem of Decoherence

Max Tegmark (The importance of quantum decoherence in brain processes ) showed a very serious problem with this. Coherent quantum arrangements tend to be short-lived when they interact with the environment. Because they can entangle with ordinary, randomly-encoded matter too, they lose the original “data” in the process.

Tegmark calculated that decoherence happens on timescales over a billion times smaller than any brain process.

Basically, your brain isn’t quick enough to be a quantum computer.