🚀 go-pugleaf

On 7 Jan 2003 15:58:32 -0800, ukcomplaint@lycos.com (UKComplaint)
wrote:

>Physicist Henry Margenau (quoted by Sir John Eccles) states that the
>components of the brain 'are small enough to be governed by
>probabilistic quantum laws' and are 'always poised for a multitude of
>possible changes, each with a definite probability'.
>
>Is Margenau's view (that actions in the brain might be subject to
>quantum effects) generally accepted withnin science?
>
>N.B. The blurb for the forthcoming Quantum Mind 2003 Conference on
>Consciousness, Quantum Physics and the Brain to be hosted by the
>University of Arizona states "recent experimental evidence suggests
>quantum nonlocality occurring in conscious and subconscious brain
>function, and functional quantum processes in molecular biology are
>becoming more and more apparent."

Physicists do like to theorize quantum events as being responsible for
mysterious neural events.  Certainly quantum theory is necessary to
understand chemical bonding, electron excitation, etc.  However,
membrane proteins are rather massive objects and the energy of binding
of ligand to receptor or to the movement of a single ion across the
membrane are rather large compared with quantal fluctuations.

Planck's constant is 7 x 10 ^^-34 J s.  That corresponds to
about 10^^-13 kcal sec/mol (compare with reactions measured
in kcal/mol) or to 4 x 10^^-15 eV s (compare with one ion moving
across the membrane at 0.1 eV).  Of course you have to account for
event duration or frequency to make the units comparable, but still
most neural activity really does occur at the macroscopic, classical
level.

There is no need to search for quantal activity to understand what we
really do observe in the brain.  Yes, there are still a lot of things
we don't understand about brain activity, but most neurobiologists
seem to think that this does not seem to be a fruitful direction to
look, Penrose and microtubules notwithstanding.