zamanlf at aol.com
Sun Apr 7 14:08:50 EST 1996
G K Gray,
The nonemotional content of this exchange has been, or at least
has been intended to be, (1) the locally-generated intracortical EEG field
(extracellular gross potential, gross response, etc.), (2) the MEG field
in the same intracortical region generated by dendritic current, (3) the
associated flow of multiunit spike activity (MSA) discovered by M Verzeano
in 27 years of research on neural network dynamics, and (4) a consistent,
electromagnetic account of their relationships.
There indeed is a neurophysiological structure that, as I see it,
is involved in the transmission of electromagnetic EEG-MEG waves over the
cortex. It is an equivalent magnetic inductance produced by a neural
gyrator, (the gyrator is an active device which can simulate
inductance) formed by localized feedback through short-range axosynaptic
projections. It is through neuronal gyration that the flow of MSA, treated
as an equivalent magnetic current, produces a curl in in the intracortical
EEG (in the EEG source region).
However, the proposed mechanism of brain wave induction has little
to do with the previous thinking you mentioned. The electromagnetic
structure of the nervous system proposed is not fundamentally related to
myelinated structures, although such structures undoubtedly will be found
to play a significant role in the nervous systems electromagnetic
structure (if such does exist). The proposed mechanism is more
fundamentally related to the cytoarchitecture of the nonmylineated cortex,
which creates within the cortex the equivalent inductance needed for
understanding the EEG, MEG and MSA electromagnetically.
The basic elements of this theory include:
1) The EEG field of a traveling wave of cortical activation.
2) The MEG field of the dendrtitic current of the same wave, whose field
lines encircle the traveling wave.
3) The circulation of MSA also associated with cortical activation waves,
which can be shown (as indicated in Verzeanos research) to circulate
about a moving locus, which is readily deduced to be the EEG wave peak.
4) A neurophysiological structure that enables the MSA to be treated as
the source of the curl (transverse space variation or slope) of the EEG
field vector directed normal to the cortex surface.
5) A demonstration that the MSA which thereby produces the EEG wave flows
around and encircles the wave peak, coordinate with the MEG field lines.
This relationship, between the MSA and MEG, also is needed if the MSA is
to be treated as a magnetic current.
6) A logical analysis of the cause and effect relationships of the simple,
ideal inductor which shows that Faradays law, if it is to provide a
logically consistent account of inductor cause and effect, indeed requires
a new term in Faradays law for magnetic current. This analysis plays an
important role in the understanding of how brain waves can be induced
through neural gyration.
7) Also, concerning the subject of consciousness, this approach includes
the possible working hypothesis that the MEG field--constituting a
macroscopic, emergent (magnetic) order parameter for the flow of MSA
through the cortex--can, for the purpose of consciousness studies in
neuroscience, be treated as an important neurophysiological element of
consciousness. (This is based on the philosophy that consciousness should
somehow be related to the macroscopic order parameters that govern nervous
system dynamics.) This hypothesis does not preclude the possibility that
consciousness can be found in some, but not all, areas of the cortex, or
other brain structures.
A recent informal survey of physicists (conducted by Don Baker) at
Los Alamos and elsewhere that do electromagnetics as a career indicate
that most of these physicists consider cause and effect as a
philosophical issue that they avoid getting involved in. It is not
necessary to their applications of Faradays law. It is important to the
issue of brain wave induction, however, because of the electrostatic
source of curl (the magnetic current needed to explain the flow of MSA
electromagnetically) needed in a causally-consistent account of even the
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