Transcranial magnetic stimulator

John E Anderson jander at
Wed Feb 2 13:33:58 EST 2000

Marco de Innocentis wrote:
> In article <389819A4.B8947CAC at>,
>   Mark Morin <mmorin at> wrote:
> > distance really isn't the operative factor--it's laws of physics
> > (current passing through an electric field at a vector perpendicular
> to
> > that field......).  I need to pull out my physics book for the exact
> > details.
> I'm a mathematical physicist, but I don't really know much about
> the structure of the brain. Do you think it would be possible to
> stimulate the temporal lobes by means of such a device?

Here is an abstract (from PubMed
of a paper by Michael Persinger, who is probably the Canadian researcher
Ramachandran alluded to in his book.  This would probably be a good
place for you to start.

1: Int J Psychophysiol 1999 Nov;34(2):163-9

Increased emergence of alpha activity over the left but not the right
lobe within a dark acoustic chamber: differential response of the left
but not
the right hemisphere to transcerebral magnetic fields.

Persinger MA

Behavioral Neuroscience Laboratory, Laurentian University, Sudbury,
Canada. mpersinger at

The percentages of alpha activity per minute over the left and right
lobes were measured for the first and second successive 15-min intervals
subjects wore opaque goggles within an acoustic chamber. A weak (5
burst-firing magnetic field was presented during this period for 1 s
every 4 s
primarily over the left or the right cerebral hemisphere. The results
that the left temporal lobe became less vigilant between the first and
second 15
min while the right temporal lobe did not. When standardized scores for
subject's measures over time and across hemispheres were employed,
alpha time over the left temporal lobe relative to the right temporal
lobe was
observed only when the transcerebral magnetic field was applied over the
hemisphere. Stimulation of the right hemisphere did not evoke this
The detection of the effects of this specific complex magnetic field
electroencephalographic activity may be more probable when the subjects
exposed to partial sensory deprivation.

Good luck!

John E Anderson
Department of Natural Sciences
University of North Florida
Jacksonville FL

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