New research on anesthesia and microtubules gives new clues about consciousness
New research on how anesthetic gases interact with microtubules in brain cells has revived interest in quantum-based theories of consciousness, particularly the Penrose–Hameroff “orchestrated objective reduction” model. Commenters dissect the underlying rat study, noting that while it suggests microtubules play some role in anesthesia, it does not uniquely support speculative quantum explanations over more conventional cellular mechanisms. The exchange broadens into debates over free will, the definition and measurability of consciousness, and whether quantum effects are needed at all given advances in classical neural networks and AI.
Role of microtubules in anesthesia and consciousness
- Study: stabilizing microtubules in rats with a drug delayed loss of righting reflex under isoflurane, suggesting microtubules are one mechanism by which this anesthetic induces unconsciousness.
- Commenters note this fits long‑standing ideas that microtubules matter for neuronal function and intracellular transport.
- Others stress this is far from showing microtubules are “the seat of consciousness”; many classical (non‑quantum) pathways could explain the effect and have not been ruled out.
Quantum mechanics and “quantum consciousness”
- Multiple comments argue everything physical is “quantum” at base, so that label alone adds little.
- Decoherence, temperature, and overdamped motion at cellular scales are cited as reasons to doubt long‑lived, brain‑relevant quantum states in microtubules.
- Critics see “quantum” here as vague and under‑specified (no clear mechanism, coherence times, or falsifiable predictions), verging on mysticism.
Penrose/Hameroff microtubule theories (Orch OR)
- Thread links this work to the Orch OR model, which many participants regard as speculative, hard to test, and widely criticized.
- Objections raised: misusing Gödel’s theorem to argue human minds surpass algorithms; lack of detailed, workable physics; prior experimental limits casting doubt on required quantum effects.
- A minority argues it’s a legitimate, if fringe, research direction worth probing experimentally.
Free will, determinism, and quantum randomness
- Long subthreads debate whether quantum indeterminacy could ground free will.
- Many argue randomness does not help: “sub‑nuclear dice rolls” are no freer than deterministic algorithms.
- Compatibilist views appear: behavior can be fully determined yet still count as “your” will. Others insist free will requires some non‑physical or non‑deterministic element; views remain unresolved.
Defining consciousness; relation to AI
- Several note we lack a precise definition that clearly distinguishes humans, animals, and systems like LLMs.
- Competing emphases:
- Consciousness as self‑awareness and theory of mind.
- Consciousness as qualia / “what it’s like” experience.
- Consciousness as possibly illusory yet psychologically compelling.
- LLMs are cited as evidence that sophisticated linguistic and problem‑solving behavior is achievable with purely classical computation, weakening arguments that intelligence requires special quantum mechanisms.
Methodology, interpretation, and media framing
- Concerns about small sample size (n≈8), variability across rats, and lack of systematic exclusion of other anesthetic targets.
- Some see the paper’s cautious claims (“supports,” “consistent with”) as reasonable; others think even that is overstated given alternative explanations.
- Popular write‑ups are widely criticized for overselling the findings and implying “proof” of quantum consciousness rather than a narrow result on microtubule involvement in anesthesia.