fMRI uses [E]M to [with a lot of help from computers] 'read' neural
activation dynamics, so it's easy to see that fields do interact with
the neural tissue. [Where there's dynamic magnetic fields there's
correlated dynamic electric fields.]
The important thing with respect to the ionic conductances that =are=
active within the brain's functioning is that they all occur in a way
that rigorously conforms to the =detailed= neural architecture.
This's not True with respect to typical external fields, which have
group-discipline that doesn't 'know' the neural Topology - so, if
they do, typical external fields can only interact with neural tissue
in relatively gross [overall] ways.
Even if you 'scramble' a low-power E[M] field, it'll still be
oblivious to the detailed neural architecture, so it tends to
pass-through 'unnoticed' [except, perhaps, for some molecular 'level'
resonances [that probably can be of consequence]].
Then there's 'ECT' which is like taking a sledge hammer to the brain,
and which has long been verified to 'scramble' brain function - it
literally makes former function inaccessible by 'jolting' the brain
to an extent that physically 'scrambles' the structure of the brain
at a detailed 'level'.
If you want to alter a brain's functioning in the best possible way,
it's best to just teach it to Think :-]
"yan king yin" <y.k.y at lycos.com> wrote in message
news:72de81ae.0304181926.7b288b7c at posting.google.com...
| Inside the brain there are ubiquitous fluctuations of
| electric fields of magnitude ~100mV, due to nerve impulses.
| Most of the standard connectionist models of the brain
| do not take this effect into account. Is this some noise
| that can be ignored?
|| I think one way to know the extent of the significance
| of this E field is to induce some random ~100mV E fields
| externally from the scalp, and see if they wreck the
| mind =)
|| Can anyone point me to some references or facts...
|| P.S. Personally I know of 2 instances. One is the
| "ephatic coupling" of parallel nerve fibers that tends
| to synchronize nerve impulses. Second is the effect of
| E fields on growth cone dynamics. Both of these theories
| are not very mainstream it seems.