"Jim Hooley" <j_hooley at yahoo.com> writes:
> does anyone know of any data on the strength/structure of the brain's
> endogenous electrical field? I guess it must be somewhere in the data from
> various scanning techniques e.g. MEG, but where?
The brain's endogenous electrical field is called the
electroencephalogram, or EEG. There is a huge amount of literature on
it, including several medical textbooks devoted to it exclusively;
although the main topic of these is what the fields look like from
outside the skull, where EEG recording is typically done. In any
case, the strength of the internal fields is on the order of 1--2
millivolts at most, and the structure is very complicated, with
regular and irregular oscillations at frequencies from 0.1 Hz or less
to 200 Hz or more, and spatial structure determined by the complex
layering of neurons in the brain.