Why don't human beings have a "memory" of pain?

Hello qpet-ga,

Your question is one of those elegant fundamental questions that I
have asked myself and have heard others ponder. It has a simple answer
and a frightfully complex answer rolled into one.


You are asking, I trust, why we can't "refeel" pain.

Painful impulses are carried by peripheral nerves which are the nerves
outside the brain and the spinal cord.  They are the nerves running to
our fingers and toes, to our internal organs, to our muscles. When
these nerves are excited in a painful way, they carry impulses to the 
brain and are  perceived as pain.  Much in the same way, sound waves
hit the ear, are carried by sensory nerves to the brain and are heard
as sound; a cookie melts in the mouth and is tasted; a feather brushes
across the cheek and is perceived as a touch.

Memory, on the other hand, is a neurologically different, highly
complex   function of the brain alone--the human's highly developed
cerebral cortex.  No nerves carry memory to the brain.  You can read
something by seeing the written page, and and you can memorize the
words. But unless you have the book in front of you, you will never
see the words, even though you can recite them.  You can hear a nice
melody played by your favorite group, and might even be able to sing
it or play it on a musical instrument, but you will not be able to
hear the original unless you put it in your DVD or MP3 player. Your
memory is active, but your senses are useless.

By the same token you can suffer pain, remember that you had it, but
can not conjure up the actual, original pain--just as you could not
conjure up an actual printed page, or the actual sound of the original
musical group.

That is the simple story.  Recently researchers are connecting pain
with memory.  They have evidence that when the body is manipulated in
a painful way as for, example when the abdomen is opened during
surgery, certain specific cells in the brain are agitated and release
chemical substances which evoke a memory of the pain.  So while the
patient feels no pain under the anesthesia of the operation, he or she
does feel pain on awaking due to the action of the agitated cells. 
This is a possible explanation for  post-operative pain.  But once
even very painful post-operative pain fades, it cannot be refelt.

Best regards,
Alanna-ga
Google Answers Researcher
answers.google.com
When you're searching for information, Google Answers.


Complexities in the Nervous Pathways Carrying Pain: From "Silent"
C-fibers to Cingulate
Gyrushttp://courses.umassmed.edu/mbb1/Limbic/CentralPain.cfm

Harvard Gazette Archives
Memories of Pain Can Come Back To Hurt
://www.google.com/search?q=memory+pain+site:.edu&hl=en&lr=&ie=UTF-8&oe=utf-8&start=20&sa=N

Search strategies:

CancerWeb Online Medical Dictionary search: pain, memory, peripheral
nerves,
http://cancerweb.ncl.ac.uk/cgi-bin/omd?pain
http://cancerweb.ncl.ac.uk/cgi-bin/omd?memory
http://cancerweb.ncl.ac.uk/cgi-bin/omd?peripheral

Starting Page: pain pathways
http://www.startingpage.com/html/health.html

Google: memory pain site:.edu
://www.google.com/search?q=memory+pain+site:.edu&hl=en&lr=&ie=UTF-8&oe=utf-8&start=20&sa=N

Great,thank you,
qpet

To answer this question completely, one would have to query his or her
creator should they believe in one.  The probable answer is that
humans (and, most likely, all other species) do not have the capacity
to recall exact pain because if they did, they would be just as
incapacitated by the memory as they were by the initial pain.

Take, for instance, the amputation of a limb: If a person was able to
recall the pain of that with 100% clarity, then the recurring memory
would be just as crippling as the act itself.  There would never be
ease for the victim because the memory would conjure up the exact
feeling of pain.

Not being able to recall the feeling of pain seems to be a built-in
survival skill for the species.  There are, however, reports of an
extended pain memory in some patients with fibromyalgia.

Abnormal Pain Memory Helps To Explain Fibromyalgia
http://www.sciencedaily.com/releases/2000/10/001030082926.htm

You've asked a very interesting question.  When I was a child and my
mother told me of her excruciating pain during my birth, I asked her
why anyone would have more than one baby if it hurt so much.  Her
answer was that "God doesn't let us remember pain."  It's also
interesting to note that I am an only child.  ;)

I have seen some support for the idea that people (babies, children,
and adults) do remember pain, at least to some extent:

"Babies Do Remember Pain", by David B. Chamberlain Ph.D.
The Primal Psychotheraphy Page
http://www.primalpage.com/babies.htm

"Abstract - Summer 2000, Volume 5, Number 2: 161-168 - Accuracy of
children's and parents' memory for a novel painful experience - MA
Badali, RR Pillai, KD Craig, K Giesbrecht, CT Chambers"
Pain Research & Management
http://www.pulsus.com/Pain/05_02/bada_ed.htm

"Pain and Memory", by Sun-Ok Song, MD and Daniel B. Carr, MD (Pain:
Clinical Updates, Volume VII, Issue 1, Spring 1999)
International Association for the Study of Pain
http://www.halcyon.com/iasp/PCU99a.html
 
Perhaps another Researcher will find that, in general, people don't
remember pain.  Or perhaps the question can be rephrased to ask why
people don't remember a certain kind of pain (for instance, amputation
of a limb, assuming that journalist-ga is right about that).

On the scientific side:

http://www.iasp-pain.org/pinfopen.html
http://www.iasp-pain.org/TC97MayJune.html

well that kinda leads to the question why we suffer when someone we
loves dies.
you might not be able to measure it but we have all experieced
emotional pain.
why we can carry that emotional baggage for years before we forget is
a bit of a mistery especially considering if darwin is correct then
why would we develop memories of pain if it were not for love then
what reason could it be

i bet darwin felt love but could never explain it

thomo
<><