> What are the prospects for being able to point to pain in a brain
> and state its intensity? If someone says "a dog doesn't feel a
> kick the way a child would," what does one reply?
Chris.heapy at gbapr.zeneca.com (Chris Heapy) writes:
> Presumably you mean within the sensory cortex? So many other
> factors influence the way pain is interpreted at higher centres
> (factors such as mood, physical activity etc.,) that measurable
> neuronal activity at any particular point becomes a poor measure
> of perception. Perhaps the best way of measuring pain perception
> at higher levels is to assess behaviour - to what extent the
> subject will go to avoid suffering the pain. Seems to me both
> child and dog would strongly avoid getting kicked if at all
Well, presumably the behavior is controlled by the brain, so whatever
we learn by assessing the behavior could also in principle be learned
by assessing the brain.
The neural systems involved in pain are still quite poorly understood,
but there is some reason to think that the anterior cingulate cortex
is involved in the highest level perception of pain. It consistently
lights up in imaging studies involving unpleasant stimuli. In a few
cases, cancer patients with intractable pain have been given
cingulotomies (removal of the cingulate area) as an experimental
treatment. They tend to report that the physical sensation is
unchanged but they no longer perceive it as unpleasant.