"Searles O'Dubhain" wrote in message
news:UJSdnX_RwpoabvjVnZ2dnUVZ_sednZ2d@comcast.com...

From "Looking For Spinoza: Joy, Sorrow, and the Feeling Brain" by
neurologist Antonio Damasio:

"At every moment of our lives the brain's body-sensing regions receive
signals with which they can construct maps of the ongoing body state. We
can picture these maps as a set of correspondences from everywhere and
anywhere in the body toward the body-sensing regions. This limpid picture
of engineering clarity, however, is blurred by the fact that other brain
regions can either interfere directly with the signaling toward the
body-sensing regions, or interfere directly with the activity of the
body-sensing regions themselves, The result of these 'interferences' is
most curious. As far as our conscious mind is concerned there is only one
source of knowledge for what is going on in the body: the pattern of
activity present at any given moment in the body-sensing regions.
Consequently, any interference with this mechanism can create a 'false' map
of what is transpiring in the body at a particular moment.

A good example of 'false' body mapping occurs under certan circumstances
when the brain filters out nociceptive body signals. The brain effectively
eliminates from the central body maps the patterns of activity that would
permit the experience of pain. There are good reasons why the mechanisms of
'd=false' representations would have prevailed in evolution. During an
attempt to run away from danger it is helpful not to feel pain that may come
from wounds inflicted by the cause of the danger (e.g. a bite from a
predator) or by the very act of fleeing from danger (running away and being
hurt by obstacles).

We now have detailed evidence about how this interference occurs. Nuclei in
the part of the brain stem tegmentum known as the periaqueductal gray (PAG)
dispatch messages toward nerve pathways that normally would convey signals
of tissue damage and lead to the experience of pain. Those messages prevent
the signals from passing on. Naturally, as a result of the filtering, we
get a 'false' body map. The body-relatedness of the process is not in
question, of course. The dependence of feeling on the 'language' of body
signals still is affirmed. It is just that what we actually feel is not
exactly what we would have felt without the wise interference of the brain.
The effect of this interference is equivalent to taking a higher dose of
aspirin or morphine, or being placed under local anesthesia. Except, of
course, that the brain is doing it for you and it all comes naturally.
Incidentally, the morphine metaphor applies quite closely because one of the
varieties of this interference uses naturally and internally generated
morphine analogues -- opioid peptides, all of them naturally manufactured in
our own body and thus called 'endogenous'. They include the endomorphines,
enkephalin, and dynorphin, in addition to the endorphins. These molecules
bind to specific classes of receptors in certin neurons of certain regions
of the brain. Thus on some occasions of need, nature proides us with the
same analgesic shot that the compassionate physician administers to the
patient suffering pain."

From "A Brief Tour of Human Consciousness" by neurologist V. S.
Ramachandran:

One of the things all medical students learn is that connections in the
brain are laid down in the fetus or in early infancy, and that once they are
laid down, there is nothing much that can be done to change these
connections in an adult. That's why when there's damage to the nervous
system, such as is caused by a stroke, there is so little recovery of
function. It is also why neurological ailments are notoriously difficult to
treat... or at least that's what we were taught. What I have seen flatly
contradicts this view and suggests that there is a tremendous amount of
plasticity or malleability even in the adult brain, and this can be
demonstrated in a five-minute experiment on a patient with a phantom limb.

It isn;t clear how this 'plasticity' of bady maps can be harnessed in the
clininc, but I'll mention another example to show how some of these ideras
can be clinically useful. Some patients can 'move' their phantom limbs, and
will say 'It's waving goodbye,' or, 'It's shaking hands with you.' But in
many other patientsthe phantom arm feels 'paralyzed,' 'frozen stiff,' 'in
cement,' or 'won't budge an inch.' Often the phantom hand goes into
involuntary clenching spasms or is fixed in an awkward painful position
which the patient is unable to change. We have discovered that some of
these patients had pre-existing nerve damage before the amputation, for
example, the arm had been paralyzed and lying in a sling. After amputation
the patient is stuck with a paralyzed phantom... as if the paralysis is
'carried over' into the phantom. Perhaps when the arm was intact but
paralyzed, every time the front of the brain sent a command to the arm
saying 'move,' it was getting visual feedback saying 'no, it won't move.'
Somehow this feedback becomes imprinted on the circuitry in the parietal
lobe or somewhere else in the brain. (We call this 'learned paralysis.')
How could this highly speculative idea be tested? Perpas if a patient were
given visual feedback that the phantom was obeying the brain's commands the
learned paralysis could be 'unlearned.' We propped up a mirror vertically
on a table in front of a prone patient, so that it was at right angles to
his chest, and asked him to position his paralyzed phatom left arm on the
left of the mirror and mimic its posture with his right hand, which was on
the right side of the mirror. We then asked him to look into the right-hand
side of the mirror so that he saw the mirror reflection of his intact hand
optically superimposed on the felt location of the phantom. We then asked
him to try to make symmetrical movements of both hands, such as clapping or
conducting an orchestra, while looking in the mirror. Imagine his amazement
and ours when he suddenly not only saw the phantom move but felt it move as
well. I have repeated this experiment with several patients, and it seems
that the visual feedback animates the phantom so that it begins to move as
never before, often for the first time in years. Many patients have found
that this sudden sense of voluntary control and movement in the phantom
produces relief from the spasm or awkward posture that was causing much of
the agonizing pain in the phantom.

Relief from a phantom pain using a mirror is surprising enough, but can the
same trick be applied to real pain in an intact arm or leg? Even though we
usually think of pain as one thing, there are at least two different types
which may have evloved for different functions. Acute pain evolved to allow
reflexive withdrawal from, for example, fire, and probably also to teach
avoidance of harmful, pain=producing objects, such as thorns. Chronic
pain -- as in a fracture or gangrene -- is a different thing altogether; it
evolved to reflexively immobilize the arm, so letting it rest and remain out
of harm's way until fully healed. Ordinarily pain is a very useful adaptive
mechanism -- a gift, not a curse. But sometimes the mechanism backfires.
We often see patients with a condition called 'complex regional pain type 1'
which includes a bizarre clinical syndrome of 'reflex sympathetic dystrophy'
or RSD. In RSD patients, what begins as a minor injury -- a bruise or
insect sting or fracture of a fingertip -- leads to the entire arm becoming
excruciatingly painful, completely immobilized, inflamed and swollen --
grossly out of proportion to the inciting event. And it lasts forever.

The evolutionary framework helps us understand how this may come about.
Remember, the original purpose of chronic pain is a temporary immobilization
to allow recovery, so when the brain sends a motor command to the arm, there
is intense pain, preventing further movement. This is normally adaptive,
but I suggest that it sometimes malfunctions and leads to what I call
'learned pain': the very act of attempting to move the arm -- the motor
command signal itself -- becomes pathologically associated with excruciating
pain. As a result, even after the inciting effect has long disappeared, the
patient still has a pseudoparalysis caused by learned pain. In 1995, I
suggested that this type of chronic pain may also benefit from mirror visual
feedback... In 1995, this was no more than a far-fetched idea but recently,
McCabe et al. (2003) tried the mirror procedure on nine patients in
placebo-controlled clinical trials. The pain went away completely and
mobility returned in many patients who used the mirrors, whereas the control
group, who used plexiglas, experienced no benefit at all. This result is so
surprising that I would have been skeptical had not Patrick Wall -- arguably
the world's leading expert on both pain and placebos -- been one of the
authors."

So it appears that the placebo effect may work by changing the body-mapping
function of the brain in any of a number of ways. It does not cure all
problems, but it does make us feel better and can promote a return to a
healthy state by changing the way we perceive and react to whatever's wrong
with our bodies.

The figure usually mentioned by researchers is that about one in three
conditions will get better without active treatment.

One could not have a "definitive study" of the placebo effect that is not
highly technical and hence more than a little arid. We're talking brain
chemistry here. It's very, very complicated.

One might take Ramachandran's suggestion and read Patrick Wall's "Pain: The
Science of Suffering". I haven't read it yet myself, but it's on my "to-do"
list.

Any claim for paranormal powers involves some sort of claim for observeable
effects. One can predict the future, see objects at great distances, float
in the air, affect the roll of dice, communicate mind-to-mind, etc. The
problem that claimants have is that they cannot actually demonstrate those
effects and thus are left with an explanation without any actual phenomenon
to explain. That's putting the cart before the horse.

Actually, Dr. Blackmore did not deny the existence of the experiences. She
merely arrived at an explanation for them that did not require the
assumption of the existence of paranormal powers. I find I'm in a similar
position. I do not deny the experiences of magic, but my explanations of
them do not require an assumption of paranormal powers.

The only option for the believer to keep on believing despite a lack of
confirmatory evidence is to hope that someone may find such evidence in the
future. However, the hope of future evidence is not a very good reason to
believe in the first place.

I don't think it's a good idea to consider magic to be "purely
psychological". However, it might not be a bad idea to regard it as "purely
neurological".

Hence Crowley's distinction between "magic" and "magick".