it's just another case of not carrying things through thoroughly
enough.
case in point was the subject of a segment on ABC TV news this
evening...
one point made is that "pain" can be turned off "cognitively"...
that such is commonly observable, eliminates the possibility of
"grandmother cells" for pain.
another thing that i found more interesting was with respect to
the "warm-pipes alternating with cold-pipes" "pain"-sensation
generators that are in Museums of Science... no actual
tissue-damaging Physical Reality, but why the sensation of
"pain"?
it's easy... the abnormal juxtaposition of the antagonistic,
sub-noxious stimulations generates relatively random activation
in the sensory pathways... TD E/I(up)... which mimics the
internal effects of the diffuse activation typical of the
spinothalamic and the spinaltrigeminal tracts, via the reticular
formation... those who have AoK can take it from here ("short
paper" & Ap3).
Cheers, ken collins
John wrote:
>> The link contains other articles concerning this ...
>>http://www.academicpress.com/inscight/04221999/graphb.htm>> The link says ..
>> Neuroscientists have homed in on the nerve cells in the seat of our
> consciousness that may tell us to feel the pain of being jabbed with a
> needle or touching a hot stove--or even to wince when someone else is in
> agony. The results, from an extraordinary experiment in patients undergoing
> brain surgery, appear in the May issue of Nature Neuroscience.
> Animal experiments in the '80s found that the anterior cingulate
> cortex (ACC), a region in the frontal cortex, is involved in pain
> perception. Brain imaging techniques in humans confirmed this role in pain
> processing, but cannot provide the kind of resolution to pinpoint how
> individual cells react to sensations.
> Seizing a rare chance to delve deeply into the ACC's inner workings,
> neuroscientist Bill Hutchison of the University of Toronto teamed up with
> neurosurgeons to study patients who undergo a last-resort treatment for very
> severe cases of depression and obsessive-compulsive disorder. The procedure
> involves drilling a tiny hole in the skull and severing a bundle of nerve
> fibers connecting the ACC, involved in these disorders, to other regions.
> Hutchison placed an ultra-thin electrode in the ACC of 11 patients by
> slipping it into their skull boreholes before the nerve fibers were cut. He
> applied various stimuli to the patients' hands, such as heat, cold, or
> sticking a needle in their fingers, and, while measuring the activity of
> individual ACC cells, asked them what they felt. Of 392 nerve cells
> monitored, he found 11--in four patients--that responded exclusively to
> pain. Some of these cells responded to pain from several stimuli, while
> others responded only to specific painful sensations. This high specificity
> suggests that the ACC is a central pain processing unit, says Hutchison.
> He also found three nerve cells that fired when the patients were
> bracing for a pain stimulus, or when they saw the researchers inflict pain
> upon themselves. This could be a cellular explanation for the saying "I feel
> your pain," says Hutchison. "These aren't simply pain signaling cells," he
> says, "they're much more sophisticated than just giving you an 'Ouch!'
> response." The findings are "wonderful," says Catherine Bushnell, a
> neurobiologist at McGill University in Montreal. The ACC, she says, "is
> probably very important in telling us how to respond to pain, whether to
> flight or to fight."
> --Michael Hagmann
>> John
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