Orchestrated objective reduction

Orchestrated objective reduction (Orch-OR) is a controversial hypothesis in the field of consciousness studies and quantum mechanics. It was proposed by Sir Roger Penrose, a mathematical physicist, and Stuart Hameroff, an anesthesiologist and professor at the University of Arizona. The theory suggests that quantum phenomena are integral to the understanding of consciousness. Specifically, Orch-OR posits that quantum coherence and quantum state reduction within the microtubules of neurons in the brain play a critical role in the emergence of consciousness.

Background

The Orch-OR theory is grounded in Penrose's interpretation of quantum mechanics, which challenges the traditional Copenhagen interpretation. Penrose argues in his books, such as The Emperor's New Mind and Shadows of the Mind, that classical physics cannot fully explain consciousness. He suggests that quantum effects in the brain contribute to the phenomenon of consciousness through a process he terms "objective reduction" (OR).

Theory

Orch-OR proposes that microtubules, which are components of the cell's cytoskeleton within neurons, are the primary site for quantum processing. According to the theory, microtubules can sustain quantum coherence long enough to perform computational operations that are relevant to consciousness. The "orchestrated" part of the theory suggests that these quantum computations are integrated into a coherent experience of consciousness through a process orchestrated by the synaptic inputs and neuronal connections.

The theory also involves Penrose's concept of objective reduction, which posits that quantum superpositions become definite states through an objective threshold related to the gravitational separation between the superposed states, rather than through observation, as suggested by the Copenhagen interpretation. In the context of the brain, this process is thought to give rise to conscious moments.

Criticism

Orch-OR has been met with skepticism from both the neuroscience and physics communities. Critics argue that the brain's warm, wet, and noisy environment is hostile to coherent quantum phenomena, which are typically observed at much lower temperatures and in isolated systems. Additionally, there is currently a lack of empirical evidence directly supporting the Orch-OR model. Critics also question the necessity of quantum mechanics in explaining consciousness, suggesting that classical computational theories of the brain are sufficient.

Implications

Despite the criticism, Orch-OR has sparked interest in the potential role of quantum mechanics in biological processes. It has encouraged interdisciplinary research between neuroscience, physics, and philosophy. If proven, Orch-OR could have profound implications for our understanding of consciousness, the nature of reality, and the potential for quantum computing in biological systems.

See Also

• Quantum mind
• Consciousness
• Microtubules
• Quantum mechanics
• Roger Penrose
• Stuart Hameroff