Full Idea
I propose that microtubules in nerve cells could give rise to a stable quantum state that would bind the activity of brain cells throughout the cerebrum and in doing so give rise to consciousness.
Clarification
'Microtubules' are tiny structures found in nerve cells
Gist of Idea
Quantum states in microtubules could bind brain activity to produce consciousness
Source
Roger Penrose (Could a computer ever understand? [1998], p.329)
Book Reference
Carter,Rita: 'Mapping the Mind' [Phoenix 2000], p.329
A Reaction
This seems to offer a physical theory to account for the 'unity' of the mind (which so impressed Descartes), but I don't quite see why being aware of things would ensue from some 'quantum binding'. I daresay 'quantum binding' occurs in the Sun.