A quantum microtubule substrate of consciousness is experimentally supported and solves the binding and epiphenomenalism problems.
Neuroscience of Consciousness 2025 DOI: 10.1093/nc/niaf011 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Review Peer reviewed |
|---|---|
| Topics | Philosophy of mind |
| Keywords | Orch or Anesthesia Binding problem Epiphenomenalism Microtubules Orchestrated objective reduction Panpsychism Quantum consciousness Consciousness theory Quantum biology Neuroscience research Brain structure |
| Citations | 22 |
| Post-publication review | 25 comments on PubPeer (opens in new tab) · last active January 2026 |
| Key findings | Intraneuronal microtubules are a functional target of inhalational anesthetics, supporting the quantum microtubule model of consciousness. |
Abstract
Recent experimental evidence, briefly reviewed here, points to intraneuronal microtubules as a functional target of inhalational anesthetics. This finding is consistent with the general hypothesis that the biophysical substrate of consciousness is a collective quantum state of microtubules and is specifically predicted by the Orchestrated Objective Reduction theory of Penrose and Hameroff. I also review experimental evidence that functionally relevant quantum effects occur in microtubules at room temperature, and direct physical evidence of a macroscopic quantum entangled state in the living human brain that is correlated with the conscious state and working memory performance. Having established the physical and biological plausibility of quantum microtubule states related to consciousness, I turn to consider potential practical advantages of a quantum brain and enormous theoretical advantages of a quantum consciousness model. In particular, I explain how the quantum model makes panprotopsychism a viable solution to physicalism's hard problem by solving the phenomenal binding or combination problem. Postulating a quantum physical substrate of consciousness solves the binding problem in principle but appears to leave us with an epiphenomenalism problem, meaning that consciousness seems to have no causal power to confer a fitness advantage, so its evolution remains as an inexplicable mystery. I propose that, contrary to a certain (zombie) intuition, the quantum approach can also solve this problem in a nontrivial way. The Orchestrated Objective Reduction (Orch OR) theory of Penrose and Hameroff embodies these advantages of a quantum model and also accounts for nonalgorithmic human understanding and the psychological arrow of time.
Comparable studies
Other narrative reviews on philosophy of mind, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| Body Consciousness: A Philosophy of Mindfulness and Somaesthetics | 2008 | Review article | |
| Phenomenology, Structure, and Dynamic of Psychedelic States | 2016 | Review | |
| Classic Hallucinogens and Mystical Experiences: Phenomenology and Neural Correlates. | 2018 | Review | |
| The lived experience of psychosis: a bottom-up review co-written by experts by experience and academics. Individuals with lived experience of psychosis, family members, and carers | 2022 | Co-written bottom-up review | |
| From autopoiesis to neurophenomenology: Francisco Varela's exploration of the biophysics of being. | 2003 | Review |
Citations in the library
Cited by 15
- Brain-penetrant microtubule-stabilizer epothilone B delays isoflurane-induced unconsciousness in mice. Neuropharmacology April 1, 2026
- Editorial: Quantum and quantum-like effects across neuroscience Frontiers in Human Neuroscience April 8, 2026
- What is consciousness and what it is for. An introduction to extended information theory. Frontiers in Psychology 2025
- Transient entanglement in minimal open XXZ spin chains: a toy-model analogy for microtubule-inspired quantum biology Frontiers in Psychiatry August 11, 2026
- A Philosophical Reassessment of Consciousness-Matter Relations Philosophy Study April 14, 2026
and 10 more in the library
Cites 21
- No-Report Paradigms: Extracting the True Neural Correlates of Consciousness Trends in Cognitive Sciences November 13, 2015
- Realistic Monism: Why Physicalism Entails Panpsychism Oxford University Press eBooks May 29, 2008
- Consciousness in the universe: a review of the 'Orch OR' theory. March 1, 2014
- Why Panpsychism Doesn't Help us Explain Consciousness Dialectica 2009
- Weak, strong, and coherent regimes of Fröhlich condensation and their applications to terahertz medicine and quantum consciousness Proceedings of the National Academy of Sciences February 26, 2009
and 16 more in the library