HongLi asked:

A couple of questions on physical pain:

Do you feel pain when you are unconscious? A common situation would be in surgery. I admit I am
not speaking from medical experience, but I hypothesise (perhaps foolishly) that people do feel pain
whilst unconscious. Except when they wake up from their anaesthesia, they forget the pain they
endured, and move on. Am I somewhat correct? Or is there proof that surgical patients don't feel pain
whilst in surgery? I would imagine they have conducted many brainwave tests and concluded from
that, that no pain is felt, but I don't believe our knowledge of the brain is complete enough to make
such a conclusion.

This thought leads to other questions, such as the nature of pain itself. Most of it is a remembrance,
and only during an infinitely small slice of time do we actually 'feel' pain. So consider being sliced by a
scalpel. As it glides through skin and flesh, no doubt it would naturally "hurt". But I argue that the pain
arises mostly from your thoughts; as you are remembering the pain before, and anticipating the pain
after... and wherever the scalpel is up to, its actual cutting of that part only contributes to a minute
amount of the pain you experience. E.g. some of you may have been unexpectedly struck with
something, perhaps sharp, very fast. It surely would not have significantly hurt at that instant. Even if,
after that instant, pain is felt, say from the resultant wound, I would still imagine most of the pain is a
combination of memory and anticipation of other instances of pain. Just a thought.

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These are good questions, and haven't been answered to everyone's satisfaction. As far as surgery
goes, there are three kinds of anesthetics. One makes you unconscious, one is an analgesic, and
one wipes your memory. The first is dangerous; unconsciousness can kill you, because it puts you
near risk for heart failure and other system failures. So anesthesiologists don't go all the way with it,
usually. The second dulls pain, yes, but doesn't usually make you unconscious without doses high
enough to be veryrisky. The third is really nasty... you seem pretty much totally conscious, you feel
pain, whatever, but you have zero long-term memory. So, I don't know... 30 seconds later or whatever
after you're screaming in agony you've completely, totally, utterly forgotten it. No memory at all. So
that'sused, much more than I'd like to contemplate, in conjunction with the others, in a very delicate
balance, which is why we pay anesthesiologists so much money. So do you feel pain during surgery?
Haha... as you can see it depends on what they use on you. What you don'tdo is rememberwhatever
you felt (in surgery) afterthe surgery. But you could be feeling it during the cutting as far as all
behavioral and physiological and EEG measures are concerned, depending on the ratios of what
they're dosing you with. That's why the otherdrugs are also used, to cut that down.

What if you're to all intents and purposes totally out on the firsttype of anesthetic above. Well, we can
check that with EEGs, and if you're down far enough, and still alive, there are virtually nobrain
responses to stimuli that would normally cause them, and cause pain, andthere are no other
behavioral responses. Do you feel pain in those circumstances? No. I mean, what do you want?
That's about as good criteria as you're going to get. Besides, we knowwhere the areas of the brain
are that cause pain. But what about lighter anesthesia, where there are no behavioral responses, but
some EEG? Now here's the grey area... and no one knows. You wake up with no memory of pain,
you've made no response... but. Let me put it this way... I'm of the school which thinks that to feel
pain you have to be conscious, to some extent; that you can't feel pain (or anything else, or have any
phenomenological experiences at all) if you're not conscious. Can there be "unconscious" feelings,
pains, etc.? Yes... given that "unconscious" means something like "partially conscious" or
"participating in processes which are also involved with conscious processes" or something like that.
But again the kicker here is just howconscious do you have to be? Haha, don't ask me... no one, and
I mean no one, including anesthesiologists, knows... because one can argue that in case where there
is somebrain activity, we've felt some pain but don't remember. Well... how do you either support or
refute that? Even waking the patient up at that point won't do it, because it turns out that we seem to
need someconsciousness in order to remember. So if they say they didn't feel pain, one can object,
again, that they had enough consciousness to feel but not enough to remember.

Now, you claim that the "nature" of pain is that it's a "remembrance" and an "anticipating". You are
not supported by the neurological evidence. The appropriate areas light upwith activation when we
feel pain. Think about it. An argument of this sort, that we really don't feel some sensation, is
applicable to anysensation. So we don't really see, hear, feel... etc.? But that begs the question of
what we're having a memory of. If we never feel much, where do our memories, which seem so
intense, come from? No, I think that both logic and data weigh against your claim... which is not to
say that both memory and anticipation don't play a part, just as they do in allsensation. It's certainly
not a black-and-white situation.

I don't know the medical literature on pain, so I can't give you references there. Some of the
philosophical literature is:

Baars, B. J. 2001. "The Brain Basis of a 'Consciousness Monitor': Scientific and Medical
Significance". Consciousness and Cognition10:159-164.

Benedetti, F., A. Pollo, L. Lopiano, M. Lanotte, S. Vighetti, and I. Rainero. 2003. "Conscious
Expectation and Unconscious Conditioning in Analgesic, Motor, and Hormonal Placebo/Nocebo
Responses". The Journal of Neuroscience23 (10):4315-4323.

Darwin, C. 1998. The expression of the emotions in man and animals.3rd ed. New York, NY: Oxford
University Press. Original edition, 1872.

Herz, R.S. 1998. "An examination of objective and subjective measures of experience associated to
odors, music, and paintings". Empirical Studies of the Arts16 (2):137-152.

Nikolinakos, D.D. 2000. "Dennett on qualia: the case of pain, smell and taste'. Philosophical
Psychology13 (4):505-522.

You could start there.

Steven Ravett Brown

That's a pretty sophisticated bundle of questions, Hong Li! But first things first: It is extremely unlikely
that anyone feels pain while they're unconscious. I am assuming (since you refer to an operative
scenario) that you have general anaesthesia in mind, and now it is (if you like) an instrumental fact of
the body's life that the gases used in anaesthesia "knock out" the transmitters of pain, i.e. disable
them from performing their normal functions. So non-functioning nerves + partially knocked out brain
translate into a pretty secure non-perceptual condition. Bear in mind, as a supportive argument, that
the brain itself contains no pain sensors, so that brain surgery is often performed with the patient fully
conscious. This argues pretty conclusively that nerves carry pain signals, and when they're gassed,
they cant.

The nature of pain is a very difficult issue to deal with even for experts, but your suggestions in the
second batch of questions are very wide of the mark. Let me ask you how you can remember a pain
when you are suffering injury unexpectedly and while you're not aware of being injured: as when you
step on broken glass in the dark or get bitten by an insect? Further: the delay which sometimes
(indeed often) occurs before we feel pain in instances of severe injury has nothing to do with memory,
but with a manner of localising trauma devised by your body to ensure that you do not pass out until
your brain has at least begun to coordinate suitable defence strategies. In any case, you are really
way off with the notion that pain signals are weak and need bolstering from memory: What memory?
Of severe pain? Then how perceived??

On the contrary, signal strength is directly proportional to the severity and/or danger to the system of
the injury, as well as the sensitivity of the organ being injured, which may differ according to criteria of
which we know very little (if anything). You are in fact, confusing something you may have read about
the way memory functions: For it is the case, very probably, that a great quantity of the stimuli which
bombard us every second of consciousness are referred to memory once your sensorium/brain
cooperative has decided that they are virtually identical to information previously collected. Then it is
more economical for your brain just to replay the memory, instead of using expensive and time
consuming "live" resources to evaluate a run of the mill stimulus. The point here is that the important
exceptions to this manner of dealing with daily experience are novelties, surprisesand emergencies.

In those cases, the stimuli are passed to the brain "naked", as it were, so that your experience is vivid
(and sometimes very confusing) because it is unfiltered. Evidently pain is "emergency" type, often
also "surprise" type, and the pain is therefore a signal to you to do something in a hurry. There is a
further criterion. Nerves usually require a refractory period after being stimulated; and so one of the
other great principles is that they report changesin stimuli, and logically "switch off" when there is no
change to report. This is one reason why pain can often be monotonously intense: but this is not
because the pain is continuously transmitted, but because nothing in its quality has changed to
arouse a nerve bundle to retransmit. Accordingly the "pain switch" (whatever it is) in the brain stays in
the "on" position. But plainly this is not a memory function.

The real problem with pain is "what it is". A signal is evidently a form of electrochemical transmission
that could hardly be pain-like. It also doesn't carry the sensation from the point of injury to the brain,
but only a signal. Maybe this is what lured you down this track. Clearly the signal must be
"understood" as something concretely sensory by the brain, which then produces an appropriate
feeling. But in what Im describing here for you, there is no intrinsic difference between hearing music
or speech, tasting food, smelling a flower or seeing a vase. All these sensation are transmission of
essentially similar kinds. Modality determines the type of stimulus and the cortex being addressed,
which must all have been calibrated over millennia of evolutionary fine tuning. But to what effect and
purpose?

Well, before you conclude, by elongating what I've just written into a scenario of a "black box" type
central command, or a "ghost in the machine" or an "homunculus", which is responsible for your
"feeling" and actually "produces" it (by what kind of trick?), so that in actuality you don't feel pain or
happiness or a nice taste on your tongue, but just imagine or believe or delude yourself into this
feeling, I hold that there is a deep-seated logical error in this theory. It is of a kind with the error that
tries to "locate" the little man in the box who sees for you, since obviously "you" cant see anything,
being the recipient of nothing but electrochemical transmissions . . .!

Well: I think that on the contrary, the ancient, intuitive version of pain etc. was in most of its essentials
correct.

You feel a pain in the foot or in your kidney, because that's where it is. And you feel it there not
because of some prestidigitation within your cortices (i.e. essentially illusory stuff) or because of
magical potions of chemistry sloshing around in your brain, but because the brain constructs for you,
while you are awake and conscious, a body map. It is because of this map that you can find the spot
on your back that itches, so that you can scratch it, even though you cant see it. Thus the injured site
transmits pain signals to that part of the brain to have the information processed wherethe pain is
that you feel, which you could not know unless the brain had first devised this virtual reality inside
you, that is made up of every point in your body which is connected to the brain by a sensor. So the
pain you feel is not because your brain receives pain messages, but because your bodies nervous
system suffers it while the brain is merely called upon to identify and bring to your consciousness the
spotthat hurts. (Again, in most cases you can find that spot in the dark.)

Whatever factual information we have is available in Ian Glynn, The Anatomy of Thought, in which a
discussion of nerves occupies about a third of the length of the book. Mind you, its a totally
materialistic theory, but at least it has the virtue of not trying to push you into a particular "philosophy".
Antonio Damasios The Feeling of what happensis another fine book on sensation, perception,
cognition and especially the role emotions play in this triad. If you really want to knowsomething
about the subject, get those books. They're written with the lay person in mind, and they give you
what must be regarded to this date the "state of the art", including everything you want to find out
about pain and memory.

Jürgen Lawrenz

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