In article <3r79sa$cgh at vixen.cso.uiuc.edu>, kspencer at s.psych.uiuc.edu
(Kevin Spencer) wrote:
> >In article <3r2qn7$458 at ixnews5.ix.netcom.com>, cabal at ix.netcom.com> >(Alexander Grijalva ) wrote:
>> >> Also, are there any side-effects attributed to MRI's? Especially in
> >> regards to the brain?
>> Claustrophobia can be a problem. The magnet has the dimensions of a
> coffin. I had never experienced claustrophobia before going into a
> magnet as a research subject, but had it in the magnet, and I have had
> problems afterwards with claustrophobia in places like airplanes and
The presence of ferromagnetic materials (eg magnetite) in organisms has
been reported in diverse species (magnetotactic bacteria and algae,
honeybees, homing pigeons, sockeye salmon, yellowfin tuna, Pacific dolphin
and many terrestrial mammals). More recently, leaders in the field
characterized single domain magnetite crystals in the human brain and
meninges, ubiquitously arranged, but in clusters. Although evidence for
man's *ability* to sense magnetic fields is controversial, the ability is
well established in the 'animal kingdom'.
As far as MRI's effects on humans, I do not know if extensive research
has been done in this area. I have read an article on MRI's effects on
spatial discrimination in rodents, however. Though I do not remember many
of the details off the top of my head, exposure to a 3.0 Tesla (?) field
up to 45 min before testing was shown to disrupt performance in a spatial
discrimination test (t-maze) among rodents (American Harvest?). This
article was published within the past two years, but I do not recall the
It is important to note, too, the epidemiological evidence of human
illnesses (leukemias, etc.) associated with proximity to high voltage
wires; studies have demonstrated in rats that magnetic fields do affect
the endocrine system, notably the pineal gland.
Though much of this sounds rather negative, the truth is, nobody really
knows yet for sure. If anyone is truly interested in pursuing this
subject further, he/she can e-mail me for relevant references.
perrin at uxa.cso.uiuc.edu