Sunday, October 23, 2005

Models or Theories?

I'm interested in trying to understand the difference.

From my dictionary:

Model: (noun)
1. A representation in three dimensions, often different scale;
2. A simplified description of a system, process, etc., put forward as a basis for theoretical or empirical understanding; a conceptual or mental representation of a thing;
3. A figure in clay, wax, etc. to be reproduced in another more durable material;
4. A car etc., of a particular design or produced in a specified year;
5. An exemplary person or thing;
6. A person or thing used, or for use, as an example to copy or imitate;
7. A person employed to pose for an artist, photographer, to display clothes etc.;
8. An actual person, place, etc., on which a fictional character is based;
9. A garment etc., by a well-known designer, or a copy of this.

1. serving as an example; exemplary, ideally perfect;
2. designating a small-scale model of the object or kind of object specified.

Theory: (noun)
1. A supposition or system of ideas explaining something, esp. one based on general principles independent of the particular things to be explained (opp. hypothesis) (atomic theory; theory of evolution);
2. A speculative (esp. fanciful) view (one of my pet theories);
3. (the sphere of) abstract knowlege or speculative thought (this is all very well in theory but how will it work in practice?);
4. the principles on which a subject of study is based (the theory of music, economic theory);
5. Math. a collection of propositions to illustrate the principles of a subject (probability theory; theory of equations). From Greek root meaning 'to look at' or 'spectator.'


I think a model or cluster of models can develop from a theory, but theories don't come from models, or shouldn't ( all cows are animals but not all animals are cows). One difference I see in the common definitions cited above is a tendency for "models" to be three dimensional representations, as opposed to "theories" which remain in the realm of abstract.

Probably use of the term "model" in matters of manual therapy comes from def. #2 above. Seems to me not much exists in treatment-land about what is what or which is which. Blurry. Seems to me everything we do is pretty much based on somebody's 'model' (i.e. 'opinion') as opposed to good theories. Can a model, even a good model, ever supplant a good theory? Or will it default to becoming Cartesian yet again? Most treatment models are incomplete, focus on one system or a few at the expense of all the others, or give one system (or a few) clear precedence as being causal. But of what?

Example: Orthopaedic thinking, chiropractic thinking: Same in that they view bone/joint position as central to the model of dysfunction. The treatment models involve trying to push bones and joints around.

Example: Rolfer thinking, Myofascial Release thinking: Same in that the focus is on connective tissue. The treatment models involve trying to push the fascia around.

Example: Massage thinking, Neuromuscular thinking: Same in that the focus is on muscle and its output function. Treatment models consist of trying to stretch/strengthen/alter muscle function and/or posture somehow.

I submit that all these approaches are Cartesian. To be fair, they helped us all get through the twentieth century before much was being learned about the brain, I'll give them that .. but are they past their due date? ALL of these approaches have to be applied through skin, if hands-on, and/or through the sensory system/cognitive system somehow if they are strictly educative. Therefore I submit that the sensory nervous system must be understood and placed into context first, prior to use of any "model", as a tool with which to understand and account for "theory", in this case "neuromatrix theory."

Further I submit that any claims of efficacy of said models that flow from the assumption that actual tissue has been changed somehow, with no accounting for the simple fact that it is likely the brain that instead has decided to change its outflow, is to not be very adept at using Occam's razor yet. Using Occam's razor, in fact, is something the treatment community knows next to nothing about. I can say this because I am a member of it.

Wednesday, October 19, 2005

Neuromatrix 7: Action Neuromatrix

The Action Neuromatrix: notes from p. 16, Topical Issues in Pain, Volume 3:

The output of the body neuromatrix directed at two systems;
1. the neuromatrix that produces awareness of the output and
2. a neuromatrix involved in overt action patterns. is important to keep in mind that, just as there is a steady stream of awareness there is also a steady output of behavior (including movements during sleep).

Apart from a few reflexes (such as withdrawal of a limb, eye-blink, and so on), behaviour occurs only after inputs have been analysed and synthesised sufficiently to produce meaningful experience. ...When we respond to pain, (by withdrawal or even by phoning for an ambulance), we respond to an experience that has sensory qualities, affect, and meaning as a dangerous (or potentially dangerous) event to the body.

I propose that after inputs from the body undergo transformation in the body-neuromatrix, the appropriate action patterns are activated concurrently (or nearly so) with the neuromatrix for experience. Thus, in the action-neuromatrix, cyclical processing and synthesis produces activation of several possible patterns and their successive elimination until one particular pattern emerges as the most appropriate for the circumstances at the moment. In this way, input and output are synthesized simultaneously, in parallel, not in series. This permits a smooth, continuous stream of action patterns.

The command, which originates in the brain, to perform a pattern such as running activates the neuromodule, which then produces firing in sequences of neurons that send precise messages through ventral horn neuron pools to appropriate sets of muscles. At the same time the output patterns from the body-neuromatrix that engage the neuromodules for particular actions are also projected to the sentient neural hub and produce experience.

In this way, the brain commands may produce the experience and movement of phantom limbs even though there are no limbs to move and no propriocptive feedback. Indeed, reports by paraplegics of terrible fatigue as a result of persistant bicycling movements (like the painful fatigue in a tightly clenched phantom fist in arm amputees) indicate that feelings of effort and fatigue are produced by the signature of a neuromodule rather than any particular input patterns from muscles and joints.

Why is there so much pain in phantom limbs? I believe that the active body-neuromatrix, in the absence of modulating inputs from the limbs or body, produces a neurosignature pattern, including the high-frequency bursting pattern that typically follows deafferentation, which is transduced in the sentient neural hub into a hot or burning quality. The cramping pain, however, may be due to messages from the action-neuromodule to move muscles in order to produce movement. In the absence of the limbs, the messages to move the muscles become more frequent and ‘stronger’ in the attempt to move the limb. The end result of the output message may be felt as a cramping muscle pain. Shooting pains may have a similar origin, in which action-neuromodules attempt to move the body and send out abnormal patterns that are felt as shooting pain. The origins of these pains then, lie in the brain.

Surgical removal of the somatosensory aeas of the cortex or thalamus fails to relieve phantom limb pain...the new theory conceives of a neuromatrix that extends throughout selective areas of the whole brain. Thus to destroy the neuromatrix for the body-self, which generates the neurosignature pattern for pain, is impossible.

(There follows rather long discussion of data collected that involved injections of anathesthetics into various parts of the brain and the results in rats, the gathering of direct evidence that the brain, neuromatrix can generate sensation on its own)...

The existance of phantoms in people born without a limb or who have lost a limb at an early age suggests that the neural networks for perceiving the body and its parts are built into the brain. The absence of inputs does not stop the networks from generating messages through out life.

In short, phantom limbs are a mystery only if we assume the body sends sensory messages to a passively receiving brain. Phantoms become comprehensible once we recognize that the brain generates the experience of the body. Sensory inputs merely modulate that experience; they do not directly cause it.


I think the implications for us as professional treaters of people are huge. We aren’t working with human bodies, we are working with human brains, every time. We are “inputting” a novel “neuromodule” which can produce a “subsignature” which can inform and alter the neurosignature of the neuromatrix. With our presence, voice, contact both psychological and physical, we use our capacity to reflect back (at least to intact nervous systems) the changes that they are making under our hands. We are literally joining nervous systems with our patients for a time.

It seems to me that this provides huge new multi-dimensional space in which to grow as professionals. Formal PT organizations should work to consolidate, reflect and support this new growth space, especially now that they can remain congruent with emergent science based thinking such as this updated pain model.

Physiotherapists/physical therapists can work with a new awareness of being 'neuromodulators', not just mobilizers or manipulators (a very Cartesian idea) or exercise suggestors/enforcers. With this new awareness, we can assist each individual to find the movement that is somewhere inside them, that needs to be expressed for the neuromatrix to reestablish correct function ( i.e., the "consummatory act" alluded to by Patrick Wall, Melzack's fellow pain researcher). Each patient can be helped to become his or her own neuromodulatory specialist, able to influence their own neuromatrix anytime they like, by enacting "neuromodulatory action."

Hands-on techniques help a neurosignature change its action output.

Let's put an end to all our perceptual fantasies we entertain about how we think we are affecting "tissue"; let's use instead this new set of concepts, this new theory that explains and universally translates all the carefully preserved and passed on traditional means by which people have always 'laid hands' on each other. Let's keep hands-on techniques and dissect away all incomplete and misleading explanations.

Neuromatrix 6: The Term "Neuromatrix"

More from Melzack, p 14. TIP3: Notes and Quotes re: Neuromatrix

Meanings of “matrix”:

1. "Something within which something else originates, takes form, or develops."

This is exactly what I wish to imply: the neuromatrix, (not the stimulous, peripheral nerves, or ‘brain center’) is the origin of the neurosignature; the neurosignature originates and takes form in the neuromatrix.

Though the neurosignature may be triggered or modulated by input, the input is only a ‘trigger’ and does not produce the neurosignature itself.

2. "'Mold’ or ‘die’ that leaves an imprint on something else."

In this sense the neuromatrix ‘casts’ its distinctive signature on all inputs (nerve impulse patterns) that flow through it.

3. "An array of circuit elements...for performing a specific function as interconnected"
The array of neurons in a neuromatrix I propose, is genetically programmed to perform the specific function of producing the signature pattern. The final integrated neurosignature pattern for the body self ultimately produces awareness and action.

For these reasons, the term neuromatrix seems to be appropriate.

The neuromatrix, distributed throughout many areas of the brain, comprises a widespread network of neurons that generates patterns, processes information that flows through it, and ultimately produces the pattern that is felt as a whole body. The stream of neurosignature output with constantly varying patterns riding on the main signature pattern produces the feelings of the whole body with constantly changing qualities.

The neuromatrix, as I conceive of it, produces a continuous message that represents the whole body in which details are differentiated within the whole as inputs come into it. We start from the top, with the experience of a unity of the body, and look for differentiation of detail within the whole.

The neuromatrix is then, the template of the whole, which provides the characteristic neural pattern for the whole body (the body’s neurosignature), as well as subsets of signature patterns (from neuromodules) that relate to events at (or in) different parts of the body.

These views are in sharp contrast to the classical specificity theory, in which the qualities of experience are presumed to be inherent in peripheral nerve fibers. Pain is not an injury; the quality of pain experiences must not be confused with the physical event of breaking skin or bone. Warmth and cold are not ‘out there’; temperature changes occur ‘out there’ but the qualities of experience must be generated by structures in the brain. There are no external equivalents to stinging, smarting, tickling, itch; the qualities are produced by built-in neuromodules whose neurosignatures innately produce the qualities.

Monday, October 17, 2005

Neuromatrix 5: The Gate Control Theory

To continue: the gate control theory (p.7, TIP 3):

Melzack discusses how in the 50s he had Donald O. Hebb as a research advisor. Hebb was corresponding with George H. Bishop. Both were fascinated with the nervous system. Bishop was researching sizes of fibers and what that had to do with pain. Hebb had written a book, “The Organization of the Brain” which ascribed pain to abnormal patterns of firing in the brain, and was studying Scottish terriers to research the role of early sensory experience on adult behavior.

Out of this context Melzack suddenly saw a possible PhD thesis, and decided to study the dogs, which were already being raised in sensory-social isolation, to see if this restriction also had an effect on pain perception. When the restricted dogs were let out they got very excited and ran around wildly. The control dogs moved slowly, cautiously exploring. He lit matches. The restricted dogs repetitively sniffed the match. For control dogs one sniff was quite enough and they ran away from the match, requiring Melzack to pursue them.. The behavior was similar for needle pricks. After several years of exposing the restricted dogs and control dogs to flaming matches and sharp needles, he concluded,

..the restricted dogs had difficulty in discriminating among stimuli, largely because of their high level of arousal. I developed the hypothesis that part of the input from an object such as a flaming match must travel rapidly up the largest fibers and fastest pathways to the brain and activate neural processes that act down on the more slowly conducted input.

The information descending from the brain, I proposed, acted at levels that had to be below the brainstem reticular formation. The brains of restricted dogs, without the advantage of prior learning, allowed all information to ascend to the brain. Flaming matches and dissecting needles were no more important than anything else in the environment, and the massive, unfiltered sensory input produced high levels of reticular arousal.

The restricted dogs, I believed, could feel pain, but the irrelevant messages were not being inhibited below the level of the reticular formation, and the relevant injury signals failed to rise above the background noise.

In 1959, while assistant professor of psychology at MIT, Melzack met Patrick Wall who was a biology professor, and they discussed pain:

We both had ideas that we shared: pain is due to patterns of nerve impulses rather than straight-line transmission of modality-specific impulses to a pain center; information that arrives at the spinal cord is filtered and selected on the basis of the total pattern of activity in stimulated fibers as well as by descending information by the brain.

The paper that resulted from their collaboration was published in Science in ‘65. It was the first theory of pain that incorporated the central control processes of the brain. Gate control theory was received with “vigorous (sometimes vicious) debate” and a lot of followup research. By the mid-70s all the textbooks included it. Physiology and pharmacology exploration of the dorsal horns was underway and clinicians were being impacted. Psychological factors in pain began to be seen as integral and not reactive. Surgical efforts were being slowly replaced by ways of moderating input. TENS entered the picture.

Physical therapists and other health care professionals who use a multitude of modulation techniques were brought into the picture, and transcutaneous electrical nerve stimulation became an important modality for the treatment of chronic and acute pain.

The current status of pain research and therapy has been evaluated and indicates that, despite the addition of a massive amount of detail, the conceptual components of the theory remain basically intact after more than 30 years.

Meanwhile Melzack moved on. He and a colleague, Kenneth Casey, coined names such as the sensory-discriminative, motivational-affective, evaluative dimensions of pain. “ These phrases seemed strange when we coined them, but they are now used so frequently and seem so ‘logical’ that they have become part of our language.”

The McGill Pain Questionnaire was developed, analgesic effects of morphine became better understood, spinal and cerebral systems underlying acute and chronic pain continued to be studied. Acupuncture began to be explained by Chinese scientists using the gate control theory and the West started taking a closer look.

Melzack collaborated with W.K. Livingston to discover “the area surrounding the aqueduct in the midbrain exerted a tonic inhibitory effect on pain. This experiment was. in part, the basis for postulating inhibitory control in the gate theory. It also led directly to Reynold’s demonstration that electrical stimulation of the periaqueductal gray produced analgesia. This study was followed by Liebeskind and Paul’s research on the mechanisms of the descending inhibition and by the discovery of pharmacological substances such as endorphins” (Candace Pert) “that contribute to it.” Melzack observed that ‘pain takes away pain’, postulated that descending inhibition tended to be activated by intense inputs, and developed studies with intense TENS. (our PT legacy...)

Then in 1978 Melzack turned his attention to paraplegics in pain. He and John Loeser proposed a central ‘pattern generating mechanism’ above the level of the section, a major advance at the time.

It did not merely extend the gate, it said that pain could be generated by brain mechanisms in paraplegics in the absence of a spinal gate because the brain is completely disconnected from the cord. Psychophysical specificity, in such a concept, makes no sense and we must explore how patterns of nerve impulses generated in the brain can give rise to somaesthetic experience.

This concept does not diminish the role of sensory inputs and spinal processing in pain due to injury, inflammation, and other pathology. It simply provides a new perspective in which the brain synthesizes raw sensory inputs and generates perceptual experience. This approach seems radical and difficult to comprehend, but I am convinced that it is the logical extension of concepts that began with the gate control theory’s incorporation of the brain in the attempt to understand pain.

Still more to come.

Sunday, October 16, 2005

Neuromatrix 4: The Evolution of New Concepts

More from Melzack:

Progress in science, according to historians of science such as Thomas Kuhn, occurs in two ways: by the gradual accumulation of information that we call ‘facts’ and by the rapid jumps in the integration of facts that occur when a new theory, concept, or ‘paradigm’ is proposed..... The power of theory was summarized briefly by Donald O. Hebb: ‘The “realworld” is a construct, and some of the peculiarities of scientific thought become more intelligible when this fact is recognized... Einstein himself in 1926 told Heisenberg it was nonsense to found a theory on observable facts alone: ‘In reality the very opposite happens. It is theory which decides what we can observe.’ ...

In the case of pain, theory not only determines what we observe in physiology, but it determines how we treat people in pain. We now know that neurosurgical lesions to abolish chronic pain usually fail and the pain tends to return. Yet theory and so-called facts about pain fibres and pathways said they should work..

(Just like the gate control theory Melzack and Patrick Wall determined 40 years ago (1962) has been PT paradigm ever since, I guess... so-called gate theory says that electrotherapy should work, yet there is a lot of 'anomalous data' i.e. a lot of people we treat that it doesn't work for beyond some temporary novelty experience... according to Kuhn in a subtext on page 6, it is the accumulation of anomalous data that forces the formation of a new paradigm/theory.)

Descartes’ views have so thoroughly permeated our concepts about physiology and anatomy that we stilll cannot escape them. In addition to the concept of a specific pain projection system, Descartes left us another legacy that has perverted our understanding of how the nervous system works....suggesting mechanical, immutable laws... In the normal world, perception and behavior are highly variable... Behaviorism, which ignored the brain and its functions, is vanishing; cognitive psychology, which recognizes the variability of perception, the malleability of memory, thought, and imagery, has now become the dominant concept.

This new approach in psychology is, happily, being paralleled by major changes in our views of brain function. We now know that the brain possesses widely distributed, parallel processing networks and that it produces an excess of neurons and synapses, so that we can conceive of memory as a sculpting process rather than a slow ‘cementing’ of synapses. This new, dynamic picture of the brain is gradually having an impact on our understanding of pain.

More to come.

Saturday, October 15, 2005

Neuromatrix 3: A Brief History of Pain

In this section, Melzack provides an overview of where pain theory came from and how it has evolved.

Quotes and notes from “A brief History of pain”, Ron Melzack, page 3, Topical Issues in Pain V. 3:
The theory of pain we inherited in the 20th century was proposed by Descartes three centuries earlier.. although humans, Descartes proposed, have a soul (or mind), the human body is nevertheless, a machine, like an animal’s body.

The impact of Descartes’ theory was enormous. The history of experiments on the anatomy and physiology of pain during the first half of this marked by a search for specific pain fibers and pathways and a pain center in the brain. The result was a concept of pain as a specific, straight-through sensory projection system. This rigid anatomy of pain in the 1950s led to attempts to treat severe chronic pain by a variety of neurosurgical lesions.

Decartes’ specificity theory, then, determined the ‘facts’ as they were known up to the middle of (the 20th) century, and even determined therapy.
I made notes from the next few pages:

Specificity theory:
1. injury activates specific pain receptors and fibers
2. these in turn project pain impulses through a spinal pathway to a pain center in the brain
3. felt pain was due to peripheral injury.
4. no room in this theory for psychological contributions to pain (i.e. attention, past experience, the meaning of the situation)
5. pain experience was held to be proportional to peripheral injury
6. back pain in absence of signs of organic disease were labelled and referred to psychiatrists
7. this concept generally failed to help those with severe chronic pain.
8. “To thoughtful observers, specificity theory was clearly wrong.”

Attempts to find a new theory:
1. “Pattern theory”: several different ones, were generally vague and inadequate.
2. “Gate Control Theory”: Came about as the pattern theories evolved.
3. “Goldscheider proposed that central summation in dorsal horns in one of the critical determinants of pain.
4. “Livingston’s theory postulated a reverberatory circuit in the dorsal horns to explain summation, referred pain, and pain that persisted long after healing was completed.”
5. “Noordenbos’s theory proposed that large-diameter fibres inhibited small-diametre fibres.. (also) he suggested that the substantia gelatinosa in the dorsal horn plays a major role in the summation and other dynamic processes described by Livingston.”
6. no explicit role for the brain other than passive receiver of messages, in any of these theories.
7. at least the theories were headed into the spinal cord away from the periphery.

It bothers me no end that my profession continues to exist and operate mostly according to outdated (since the 1950's !) Cartesian theories on pain, especially in the orthopaedic side of it. The orthopaedic branch of the extensive PT profession has generally followed closely behind traditional medical orthopaedic thinking, which is very Cartesian in outlook and practice: In a nutshell, it sounds something like this: If there's pain in the leg, there must be something in the leg that we should cut out, or a joint we should replace, so that it won't hurt the patient anymore. If there's nothing we can see that should be cut out, and the patient still hurts, it must be arthritis, or else the patient must be crazy. Send them to physio.

The physio mentality has been, If there's pain in the leg, something must be weak. If we strengthen it, it will become strong and the pain might go away/ we can wiggle waggle joints, get better movement from them and the pain might go away. If the pain doesn't go away, it wasn't coming from the joints (the patient is crazy) or else I'm not skilled enough (yet) to overcome this person's arthritic pain. Send them back to the doctor.

The orthopaedic theory of pain seems accurate some of the time, and those with their hips replaced or knees replaced are usually pretty happy with the results. But the power of the successes have eclipsed the failures of this way of thinking, this memeplex of ideas. No other sources or mechanisms for pain generation seem to be considered legitimate by this cultural force within healthcare. Lots of middle aged and older people have audibly creaking and clunking joints and are in no particular distress or pain about it. "Arthritis" in the form of joint change shows up on everyone's x-ray sooner or later.. not everyone gets pain. Conversely, lots of young adults have lots of distressing and persistant pain without any x-ray changes. What's wrong with this picture?

Long ago I began exploring soft tissue work. I knew the orthopaedic premise was outright wrong for most peoples' pain, and much too narrow to accommodate either them or me. After having delved into the pain sciences I am beginning to feel vindicated.

Friday, October 14, 2005

Neuromatrix 2: Outline of the Theory

(R. Melzack in Topical Issues in Pain Vol.3, page 13):

Outline of the (neuromatrix) theory
The anatomical substrate of the body-self, I propose, is a large, widespread network of neurons that consists of loops between the thalamus and cortex as well as between the cortex and limbic system. I've labelled the entire network, whose spatial distribution and synaptic links are initially determined genetically and are later sculpted by sensory inputs, as a 'neuromatrix'.

The loops diverge to permit parallel processing in different components of the neuromatrix and converge repeatedly to permit interactions between the output products of processing. The repeated cyclical processing and synthesis of nerve impulses through the neuromatrix imparts a characteristic pattern: the 'neurosignature'.

The neurosignature of the neuromatrix is imparted on all nerve impulse patterns that flow through it; the neurosignature is produced by the patterns of synaptic connections in the entire neuromatrix.

All inputs from the body undergo cyclical processing and synthesis so that characteristic patterns are impressed on them in the neuromatrix. Portions of the neuromatrix are specialized to process information related to major sensory events (such as injury, temperature change, and stimulation of erogenous tissue) and may be labelled as neuromodules, which impress subsignatures on the larger neurosignature.

The neurosignature, which is a continuous outflow from the body-self neuromatrix, is projected to areas in the brain - the 'sentient neural hub' - in which the stream of nerve impulses (the neurosignature modulated by ongoing inputs) is converted into a continually changing stream of awareness.

Furthermore, the neurosignature patterns may also activate a neuromatrix to produce movement. That is, the signature patterns bifurcate so that a pattern proceeds to the sentient neural hub (where pattern is converted into the experience of movement), and a similar pattern proceeds through a neuromatrix that eventually activates spinal cord neurons to produce muscle patterns for complex actions.

The four components of the new conceptual nervous system, then, are
1. the body-self matrix;
2. cyclical processing and synthesis, in which the neurosignature is produced;
3. the sentient neural hub, which converts (transduces) the flow of neurosignatures into the flow of awareness; and
4. the activation of an action neuromatrix to provide the pattern of movements to bring about the desired goal.

I find this information very intriguing. I'm so glad that Melzack has moved beyond TENS (Transcutaneous Electrical Nerve Stimulation).

It seems to me that by moving up into the brain he is making room in theory, in science, for what WE do, PTs... particularly those of us who treat hands-on (!) ..a fourth category he neglected to mention, that should be right in there with injury, temperature change and erogenous stimulation. WE modulate inputs etc. but with our HANDS, voices, ideas, presence, not with TENS, meaning that the brain will never adapt because the input will always vary according to what the output (inherent tissue motion or body movement) is, and will never be the same twice, unlike TENS. Take pain for example. Another nervous system (the therapist’s) functioning at a more ‘coherent’ (less painful) level will out-modulate inputs better than any TENS unit. Any day. I’ll lay odds on that.

So maybe what we are actually doing at the finer levels of brain function, is creating "a major sensory event", producing new "neuromodules, which impress subsignatures on the larger neurosignature." I quite like the idea that with treatment, my hands on someone's body creates a major sensory event that can in turn produce a neuromodule which can impress a subsignature on a neuromatrix. Hmmnn... really like that idea. (How can you tell I've rolled this over and over in my mind?)

Wednesday, October 12, 2005

Neuromatrix 1: First Contact

I'd read about Melzack’s gate control theory ages ago before picking up Topical Issues in Pain, Volume 3 (edited by Louis Gifford of the UK. published in 2002. available from ). This book is a third in a series dealing with pain and is subtitled, "Sympathetic Nervous System and Pain." Ron Melzack, from McGill University in Canada, worked for decades with Patrick Wall in Britain on uncovering the mysteries of pain.

My interest perked up right away when I read this on page 12, by Ron Melzack, on his updated concept of "neuromatrix":

It is evident that the gate control theory has taken us a long way. Yet, as historians of science have pointed out, good theories are instrumental in producing facts that eventually require a new theory to incorporate them. And this is what has happened. It is possible to make adjustments to the gate theory...But there is a set of observations on pain in paraplegics that just does not fit the theory. This does not negate the gate theory, of course. Peripheral and spinal processes are obviously an important part of pain, and we need to know more about the mechanisms of peripheral inflammation, spinal modulation, midbrain descending control, and so forth. But the data on painful phantoms below the level of total spinal section indicate that we need to go beyond the foramen magnum and into the brain.

My analysis of phantom limb phenomena has led to four conclusions that point toward a new conceptual nervous system.

First, because the phantom limb (or other body part) feels so real, it is reasonable to conclude that the body we normally feel is subserved by the same neural processes in the brain; these brain processs are normally activated and modulated by inputs from the body, but they can act in the absence of any inputs.

Second, all the qualities we normally feel from the body, including pain, are also felt in the absence of inputs from the body; from this we may conclude that the origins of the patterns that underlie the qualities of experience lie in the neural networks in the brain; stimilui may trigger the patterns but do not produce them.

Third, the body is perceived as a unity and is identified as the 'self' distinct from other people and the surrounding world. The experience of a unity of such diverse feelings, including the self as the point of orientation in the surrounding environment, is produced by central neural processes and cannot derive from the peripheral nervous system or spinal cord.

Fourth, the brain processes that underlie the body self are, to an important extent that no longer can be ignored, 'built-in' by genetic specification, although this built-in substrate must, of course, be modified by experience.

After reading Melzack’s perception of what he calls a neuromatrix, I felt my mind do one of those brain avalanches we all get sometimes when a lot of disparate ideas suddenly collapse into each other and begin to make clearer sense. Something called a "body-self neuromatrix" puts out a "neurosignature" that is projected to areas in the brain called "the sentient neural hub"... "in which the stream of nerve impulses (the neurosignature modulated by ongoing inputs) is converted into a continually changing stream of awareness."

Long ago I learned a D.O.’s theory about embryologic connections that don’t fade, regardless of what happens downstream; all the bits that develop together or come from the same "family tree" germ layer will remain in communication, and that pain can spread along this "family tree": Even though the ‘family members’ (embryologic cellular relatives) may be spread far apart in the adult body, they don't ever lose track of each other.

The D.O. theory and the neuromatrix theory didn’t quite collapse into one another successfully, and still haven’t… I hopped over to neuromatrix theory and am still there at present. (However, I look for connections; this blog is an active search for connections. There will be plenty of embryology placed here, therefore.)

As for a "neuromatrix" and a "sentient neural hub" I remember reading (V.S. Ramachandran I think) about people with agenesis of an arm or what have you, who nevertheless could "feel" they had a phantom arm. The sense of an arm, a real arm doing real things, with no prior peripheral input experience. Nothing for the brain to have worked with, except itself.

This is just page 13 of this book of 223 pages. Melzack supplies only the introductory essay, up to page 19. Already I can see that he is talking about something at least one order of magnitude beyond where my mind usually goes when I think about brain function. And I'm thinking this is where David Butler has taken off with his idea of "virtual bodies" and "virtual body parts."

Monday, October 10, 2005

Mourning yoga

I wonder whatever happened to yoga? Thirty years ago the approach to yoga was NOT stretching. It was to go slowly in the direction of a pose until the first tiny resistance was felt, and no further. It is so easy to override that first tiny signal that going very slow, just drifting in a direction really, was the only way to pick up on it. Sensitivity to 'The Signal' was the important thing, not how far you could go.

One was to stop right there and go no further, just hang out with the first tiny non-nocioceptive tug and abdominally breathe, and wait. Hang out with the signal and get to know it, find out as much about it as possible; stretch only applied to the time factor, never the tissue.

Once in awhile the tug went away but usually it didn't, so after a minute or so one moved to the next pose, usually in an opposite direction or a different segment of body.

Each pose was to be attempted no more than 3 times in one day. Usually the second attempt took one quite a bit further than the first, but still the 'Goal' was to find that first tiny tug and go no further. The third one usually took one no further forward than the second, but the third one seemed to "lock in" the increased range gained at the second go, and sort of mark or attentuate one's ability to note The Signal.

NONE of this was forceful. That is against the whole point of yoga, the way I learned it anyway, which is to introduce mind, brain and body to each other, every time as if for the very first time, and let them get to know each other, promote intimate inter/(intra) awareness.

This was not stretching. It was peaceful and soft and yielding and relaxing and accepting and embracing of obstacle, until such time as the obstacle to one's movement plan disappeared/decided to go away all by itself. Literally, one sought out these obstacles to easy slow drift, to hang out with them and get to 'know' them, at sub-nocioceptive threshold. The point was to sensorially amplify even the tiniest obstacle and miss nothing. Wear a mental microscope and get in close.

Just doing that, noting obstacles and observing their changes, led to their eventual and predictable disappearance over a few weeks time and practice. I ended up effortlessly being able to do things I'd never in a million years thought I could do with this body. I loved yoga, practiced every day for two years.

Now I can look back and see that it was a system for self-neuromodulation, for building a more solid relationship among all the different sensorymotor modules of brain/cortex, but back then the only cognition available was to cultivate the right attitude.

At that point, I felt I'd gone as far as I wanted to, my mind had a good system built for tuning into whatever my body was saying kinesthetically, and I was done with actually putting in the time to practice yoga. I can just 'go there' now, anytime, and I'm still pretty flexible physically as well 30 years later. I still hang out with the obstacles, only they are the ones in other peoples' bodies these days, less frequently the ones in my own.

This is a longwinded way of saying that yoga shouldn't be synonymous with stretching. That is absolutely backwards. It should be synonymous with kinesthetic sensitization instead. The point of it has been lost under a tsunami of stretching; I hate what yoga seems to have turned into, and all the injuries it causes. I treat my share of yoga teachers/students, unfortunately. I try, I really try to get them to understand that yoga is all about taking forever, being lazy, not trying.. just being. Just being sensitive to one's own human antigravity suit for awhile. Just the way it is. Not trying to change it at all. (The lazy part is, it will change all by itself. No effort is required except to show up for a half hour or hour of exploring and hanging out.)

"If the cell body of a motor neuron were the size of a tennis ball, its dendrites would fill a room and its axon would extend, like a 0.5-in. garden hose, nearly half a mile." (Jack Nolte, neuroanatomist)


I have worked for over three decades with people and their aches and pains, as a lisenced physiotherapist. I read extensively outside my own field, mostly science-related topics, for enjoyment, enrichment, and education. A few of the many mindscapes out there that especially intrigue me, and that I feel pertain directly to and help influence cognitive choices I make in the midst of my career, are embryology, evolution, and neuro/pain sciences.

My hope is that this blog will provide space for development of my perceptions and theories, which, being mostly kinesthetic ones, have up to now been invisible to the outside world. These perceptions exist; how could they not? Treatment of what I like to call "the human antigravity suit" is a neurologically interactive process. What I learn and glean from these "outer" worldviews helps me make sense of kinesthetic perception, which is real to me but invisible to everyone else (everyone else, that is, except in the moment, and to the individual I'm working with at the time). What I do, what I see in peoples' responses, with concepts from these broad outside (of physiotherapy) sources I construct my own worldview, and may (who knows) be able to in some small way help others who work with peoples' bodies/minds/nervous systems.