The brain is both neurocomputer and quantum computer

Stuart R. Hameroff

Research output: Contribution to journalArticlepeer-review

77 Scopus citations


In their article, Is the Brain a Quantum Computer,? Litt, Eliasmith, Kroon, Weinstein, and Thagard (2006) criticize the Penrose-Hameroff "Orch OR" quantum computational model of consciousness, arguing instead for neurocomputation as an explanation for mental phenomena. Here I clarify and defend Orch OR, show how Orch OR and neurocomputation are compatible, and question whether neurocomputation alone can physiologically account for coherent gamma synchrony EEG, a candidate for the neural correlate of consciousness. Orch OR is based on quantum computation in microtubules within dendrites in cortex and other regions linked by dendritic-dendritic gap junctions ("dendritic webs") acting as laterally connected input layers of the brain's neurocomputational architecture. Within dendritic webs, consciousness is proposed to occur as gamma EEG-synchronized sequences of discrete quantum computational events acting in integration phases of neurocomputational "integrate-and-fire" cycles. Orch OR is a viable approach toward understanding how the brain produces consciousness.

Original languageEnglish (US)
Pages (from-to)1035-1045
Number of pages11
JournalCognitive science
Issue number6
StatePublished - 2007
Externally publishedYes


  • Anesthesia
  • Consciousness
  • Dendritic webs
  • EEG
  • Gamma synchrony
  • Gap junctions
  • Integrate and fire
  • Microtubules
  • Neurocomputation
  • Orchestrated objective reduction (Orch OR)
  • Quantum computation

ASJC Scopus subject areas

  • Experimental and Cognitive Psychology
  • Cognitive Neuroscience
  • Artificial Intelligence


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