A Unified Theory for Physical Therapy and the Treatment of Pain

[BB]

I don't want to distract from the purpose at hand here, but this thread has gained a little attention and discussion on RE. I offerred to copy the thread over there as well. I already asked this of the moderators, but does anybody who has posted here have a problem with me copying their posts from this thread to the one I'm copyiing onto RE?

[Diane]

Not a bit.

[BB]

Damasio describes a mechanism to account for changes to the proto self which would account for the inhibitory effect of an explanation. He calls it the "as-if body loop."

from p. 281 of The Feeling of What Happens:

In this alternate mechanism, the representation of body-related changes is created directly in sensory body maps, under the control of other neural sites, for instance, in the prefrontal cortices. It is "as if" the body had really been changed, but it has not. The "as if body loop" mechanism bypasses the body proper, partially or entirely, and I have suggested that bypassing the body saves both time and energy, something that may be helpful in certain circumstances. The "as if" mechanisms are not only important for emotion and feeling, but also for a class of cognitive processes one might designate as "internal simulation."

We are able to bring about the neural map representations for a change that was not externally simulated. As far as the brain is concerned, however, it is "as if" it had. This allows us to percieve changes that we create mentally. Thus we have a mechanism that allows us to percieve the neural representations of our explanations that are based on past experience.

He goes on at p. 283:

First-order neural maps in both subcortical and cortical regions represent changes in body state, regardless of whether they were achieved via "body loop," "as if body loop," or combined mechanisms.

Our neural maps can represent changes that are a combination of mechanisms. All of this will be important info for considering placebo.

[bernard]

but does anybody who has posted here have a problem with me copying their posts from this thread to the one I'm copyiing onto RE?

No problem at all, we are a free and unrestricted board.

[BB]

Quickly, I want to return to the description of the autobiographical self.

From P. 174 of The Feeling of What Happens:

The autobiographical self is based on autobiographical memory which is constituted by implicit memories of multiple instances of individual experience of the past and of the anticipated future.

[BB]

The placebo describes the response when a person is given what they percieve to be a treatment, that is actually a passive treatment, but still elicits a treatment response.

Lets examine some instances of placebo as described by Patrick Wall:

First, he describes the findings of the use of placebo ultrasound after wisdom tooth extraction. It showed a decrease in inflammation and swelling despite whether the machine was on or off. Also, if the treatment was performed by the patient on themselves instead of by the physician, the treatment effect did not occur.

Next, he describes patients with angina undergoing a substernal ligation surgery. Amazingly, a double blinded study was performed on these patients with one group recieving placebo surgery. In other words, the arteries were not ligated. The mojority of patients in both groups of patients showed great improvemenet in the amount of reported pain, in their walking distance, in their consumption of drugs, and in some cases, in the shape of their electrocardiogram. Also, the improvement was maintained over the course of 6 months.

3rd, in a group with headaches severe enough that they were in the emergency room. Two groups were given active drugs, both of which had previously shown to be superior to placebo in calm patients. The third group got a shot of saline. All three groups showed an identical reduction in pain. The patients expectation of recieving a strong treatment since they were in the ER, influenced the treatment effect.

4th, a post-operative group. One group recieved a placebo first, after which the second shot was morphine. The treatment effect was poor for both shots. The other group recieved the active morphine treatment first, which was followed by the placebo treatment. Both had a strong effect. The placebo may be indistinguishable from the drug after the patient has experienced the drugs effect.

What do all of these examples have in common? They are all based upon the patients expectation of a treatment effect. If a positive effect is expected, it happened.

These expectations are based on culture (such as in example one and two, where a doctor and surgery is expected to provide relief), experience (as in examples 3 and 4 where a previous experience with the treatment influenced its outcome.

I want to bring 2 quotes from Wall's Pain: The Science of Suffering;
p. 136:

The placebo response is played out on the stage of expectation, which is created by the patients and their experience and culture, by the reputation of the therapy and by the attitude of the therapists.

and from p. 139:

All of this leaves us with a question, "What precisely is a placebo?" It can not be a stimulus because, by definition, it is completely inactive. if a placebo is given in complete secrecy, nothing happens. We have seen that the placebo response is linked to the patients expectation. Part of the response of a patient to any therapy relates to the patient's expaectation of a benefiecial effect. There is therefore a placebo component in any therapy.

More to come....

[bernard]

Hi Cory,

That is a magnificient work and I made a little link for RE. (Already posted)

The Unified Theory.

It is not more necessary to copy the thread in the other site.
BTW, your choice will be mine.

[BB]

Thank you very much Bernard! You just made my life much easier.

[Diane]

Thanks again for pulling all these things together Cory.
The common feature in all but the fourth intervention, is that the patient was touched one way or another, even if only to be given a shot of saline. In the first case, they were touched with fake ultrasound.. their touch receptors were stimulated, weren't they?

[BB]

You're welcome Diane. Yes their touch receptors were stimulated, and not all of the ultrasound was fake. It didn't matter.

Time for the tie together post for placebo and explanations.

We talked about how expectations depend upon explanations.

Through "as if body loops" as described by Damasio, we have discussed a mechanism through which ideomotion can be expressed based upon an explanation.

Lastly we discussed Wall's assertion that Placebo is based upon expectation.

I want to bring in another quote from Wall's Pain: The Science of Suffering from p. 151-152:

Finally, we need to reexamine whether pain signals the presence of a stimulus or whether it signals the stage reached in a sequence of possible actions. The placebo phenomenon represents a profound challenge to these alternatives. The placebo, by difinition, is not active and so cannot change the signal produced by the stimulus. it can hardly be categorized as a distraction of attention. Someone who has received placebo treatment for pain does not actively switch attention to some alternative target. On the contrary, they passively await the onset of the beneficial effect of the placebo while continuing the active monitoring of the level of pain. If, however, the sensation of pain is associated with a sieries of postential actions, such as remove the stimulus, change posture, and seek safety, then eventually the appropriate action is to apply therapy. If the person's experience has taught him that a particular action is followed by relief, then he responds if he believes the action has occurred. In this scheme of thinkng, the placebo is not a stimulus but an appropriate action. As such, the placebo terminates and cancels the sense experessed in terms of possible action. Pain is then best seen as a need state, like hunger and thirst, which are terminated by a consummatory act.

Placebo, which is based on expectation, is an appropriate action. A pure placebo, cancels pain because it provides an appropriate action sequence. A mechanism that would account for this is the "as if body loop." It provides a neural representation in absence of the peripheral input to generate it.

I think placebo must be considered an expectation in the context of pain. Since attention is needed in pain, and consciousness requires an explanation, an expectation will always be generated. Therfore, as Wall says, there is a placebo component to every therapy.

So, another generality: Those treatments which are consistent with the expectated relieving therapy, will be successful.

One thing we must consider as a large responsibility on our part, is that this will add to future expectations. We can provide explanations that create expectations which dictate future treatment and response. An example to consider in this scenario is the "bone out of place" explanation. "The clinician said they moved my bone in to place. It fixed my pain. If I have pain, I must have a bone out of place. If I have pain, I need a bone put back in place."

[Jon Newman]

Some other, relatively recent, research on this.

[Jon Newman]

One thing we must consider as a large responsibility on our part, is that this will add to future expectations. We can provide explanations that create expectations which dictate future treatment and response. An example to consider in this scenario is the "bone out of place" explanation. "The clinician said they moved my bone in to place. It fixed my pain. If I have pain, I must have a bone out of place. If I have pain, I need a bone put back in place."

There is at least one other element at play in this scenario and that is perceived controllability (and I suppose if the patient can control their pain then it is veridical controllability.) I try, as much as seems reasonable, to leave the locus of control where it does the most good and in my opinion, where it belongs whether it has a measurable impact on the acute pain rating or not.

[Diane]

Jon, slam in post 86, then dunk in post 87.
Exactly.

[Diane]

This recent blog of Deric Bowds might be of interest.. it points out how the physical sense of 'self' can easily be taken awry. It's very informative to look at the graphics and links within the blog.

[BB]

Jon,
Great articles. Thanks.

I want to come back to my last post to reiterate a point.

The "as if body loop" provides a way in which the neural representations are present "as if" a body change has happened. The placebo, must be considered an appropriate action, because it creates a neural representation that is "as if" that action did in fact take place. As far as the neural representations are concerned, it did. This is why it "cancels and terminates" pain.

Jon,
The percieved controllability article is a great transition to explanatory style, and learned helplessness. I'm hoping to wrap up this section with a discussion of these. Thanks again.