Brain Uses Quantum Effects, New Study Finds [video]
A new paper claiming that neurons may exploit quantum effects in microtubules has revived long‑running debates over whether the brain uses quantum phenomena in a functionally meaningful way, beyond the ordinary quantum chemistry underlying all biology. Commenters contrast modest, well‑evidenced examples of “quantum biology” (such as photosynthesis and enzyme catalysis) with far more speculative claims that quantum processes could explain consciousness or free will, noting the lack of experimental support for long‑lived coherent states in the warm, wet brain. The thread broadens into arguments over determinism, the interpretation of quantum randomness, and whether any of this would actually change how we think about responsibility, computability, or the nature of mind.
Scope of the “quantum brain” claim
- Several comments stress that the interesting claim is not “the brain uses quantum mechanics” (trivially true for all chemistry) but that neural systems may use light-based internal signaling and microtubules as photonic/quantum structures for ultrafast information processing.
- One reader notes the paper is mostly theoretical/simulation-based, with very limited experimental data (a few bulk fluorescence measurements) that might have simpler explanations.
Skepticism and “woo” concerns
- Multiple commenters expect this to trigger a wave of speculative consciousness/“quantum soul” narratives and are wary.
- Biophysics-minded participants argue that maintaining long-range coherence/entanglement in warm, wet tissue is extremely hard; biology would need to solve problems quantum engineers struggle with in cryogenic vacuum.
- Others note that neural computation already has well-established, classical mechanisms; any extra quantum layer would need strong evidence.
Quantum biology more broadly
- It is widely acknowledged that all biology rests on quantum chemistry.
- Specific putative or accepted cases are mentioned: photosynthesis, enzyme catalysis, tunneling/coherence in biomolecules, possible roles in olfaction, and ultra-weak photon emission from neurons.
- Some argue it would be surprising if evolution didn’t exploit useful quantum effects wherever possible.
Free will, determinism, and quantum randomness
- A large subthread debates whether quantum randomness can underwrite free will.
- One side: randomness vs determinism exhaust the options; adding quantum noise does not produce the kind of agency people care about.
- Others propose that if agents can in some way influence quantum outcomes, that might ground an intuitive notion of free will.
- Compatibilist views (free will as acting from one’s motives under causal laws) are contrasted with incompatibilist and “illusionist” positions; linked philosophy resources are discussed.
Quantum mechanics, computability, and consciousness
- Penrose-style arguments appear: human mathematical insight or consciousness might be non-computable in the Turing sense, possibly tied to quantum state reduction.
- Counterpoints: if a process is physically realizable, many argue it should in principle be computable by some (perhaps non-Turing) machine; brain dynamics are finite-state and do not literally solve the halting problem.
- Several commenters doubt that tying consciousness to quantum effects yields testable predictions or explanatory payoff at present.
Meta-reactions
- Some applaud the boldness and potential of the research direction; others see it as overinterpreted or premature.
- A recurring theme: enthusiasm for quantum biology as a field, coupled with insistence on clear experimental evidence before revising mainstream views of cognition or consciousness.