"On the Razor's Edge"

[Diane]

I want to bring a section of the book, Tree of Knowledge (http://www.amazon.com/Tree-Knowledge-Humberto-R-Maturana/dp/0877736421) (by Humberto R Maturana (http://www.oikos.org/maten.htm) and Francisco J Varela (http://en.wikipedia.org/wiki/Francisco_Varela)), here. It is a succinct exploration of the difficulties inherent in discussing the human nervous system while remaining scientifically and philosophically safe from error.
From p. 129:
On the Razor's Edge
The most popular and current view of the nervous system considers it an instrument whereby the organism gets information from the environment which it then uses to build a representation of the world that it uses to compute behavior adequate for its survival in the world. This view requires that the environment imprint in the nervous system the characteristics proper to it and that the nervous system use them to generate behavior, much the same as we use a map to plot a route.

We know, however, that the nervous system as part of an organism operates with structural determination. Therefore, the structure of the environment cannot specify its changes, but can only trigger them. We as observers have access both to the nervous system and to the structure of its environment. We can thus describe the behavior of an organism as though it arose from the operation of its nervous system with representations of the environment or as an expression of some goal-oriented process. These descriptions, however, do not reflect the operation of the nervous system itself. They are good only for the purpose of communication among ourselves as observers. They are inadequate for a scientific explanation.

If we reflect a moment on the examples given earlier we will realize that our first tendency to describe what happens in each case centers, in one way or another, on the use of some form of the metaphor of "getting information" from the environment represented "within". Here, the authors point to a figure depicting the "little man" inside the brain, operating visual mechanisms to see the outer world on a "screen" inside the brain. Who runs the "little man's" "brain"? Our course of reasoning, however, has made it clear that to use this type of metaphor contradicts everything we know about living things. We are faced with a formidable snag because it seems that the only alternative to a view of the nervous system as operating with representations is to deny the surrounding reality. Indeed, if the nervous system does not operate - and cannot operate - with a representation of the surrounding world, what brings about the extraordinary functional effectiveness of man and animal and their enormous capacity to learn and manipulate the world? If we deny the objectivity of a knowable world, are we not in the chaos of total arbitrariness because everything is possible?

This is like walking on the razor's edge. On one side there is a trap: the impossibility of understanding cognitive phenomena if we assume a world of objects that informs us because there is no mechanism that makes that "information" possible. On the other side, there is another trap: the chaos and arbitrariness of nonobjectivity, where everything seems possible. We must learn to take the middle road, right on the razor's edge. At this point the authors direct the reader to a figure showing a version of the sailing of a ship between the monster and the whirlpool, the Scylla monster (http://images.google.com/images?svnum=10&um=1&hl=en&rlz=1B3GGGL_enCA226CA227&q=Scylla&btnG=Search+Images) of representation and the Charybdis (http://images.google.com/images?svnum=10&um=1&hl=en&rlz=1B3GGGL_enCA226CA227&q=Charybdis&btnG=Search+Images) whirlpool of solipsism (http://en.wikipedia.org/wiki/Solipsism).
In fact, on the one hand there is the trap of assuming that the nervous system operates with representations of the world. And it is a trap, because it blinds us to the possibility of realizing how the nervous system functions from moment to moment as a definite system with operational closure. We shall see this in the next chapter.

On the other hand, there is the other trap: denying the surrounding environment on the assumption that the nervous system functions completely in a vacuum, where everything is valid and everything is possible. This is th other extreme: absolute cognitive solitude or solipsism, the classic philosophical tradition which held that only one's interior life exists. And it is a trap because it does not allow us to explain how there is a due proportion or commensurability (http://www.google.com/search?hl=en&rlz=1B3GGGL_enCA226CA227&q=define%3A+commensurability&btnG=Search) between the operation of the organism and its world.

Now, these two extremes or traps have existed from the very first attempts to understand cognition, even in its most classical roots. Today, the representational extreme prevails; at other times the opposing view prevailed.

We wish to propose now a way to cut this apparent Gordian knot (http://en.wikipedia.org/wiki/Gordian_Knot) and find a natural way to avoid the two abysses of the razor's edge. By now the attentive reader has surmised what we are going to say because it is contained in what we said before. The solution is to maintain a clear logical accounting. It means never losing sight of what we stated at the beginning: everything said is said by someone. The solution, like all solutions to apparent contradictions, lies in moving away from the opposition and changing the nature of the question, to embrace a broader context.

The situation is actually simple., As observers we can see a unity in different domains, depending on the distinctions we make. Thus, on the one hand, we can consider a system in that domain where its components operate, in the domain of its internal states and its structural changes. Thus considered, for the internal dynamics of the system, the environment does not exist; it is irrelevant. On the other hand, we can consider a unity that also interacts with its environment and describes its history of interactions with it. From this perspective in which the observer can establish relations between certain features of the environment and the behavior of the unity, the internal dynamics of that unity are irrelevant.

Neither of these two possible descriptions is a problem per se: both are necessary to complete our understanding of a unity. It is the observer who correlates them from his outside perspective. It is he who recognizes that the structure of the system determines its interactions by specifying which configurations of the environment can trigger structural changes in it. It is he who recognizes that the environment does not specify or direct the structural changes of a system. The problem begins when we unknowingly go from one realm to the other and demand that the correspondences we establish between them (because we see these two realms simultaneously) be in fact a part of the operation of the unity - in this case, the organism and nervous system. If wee are able to keep our logical accounting in order, this complication vanishes; we become aware of these two perspectives and relate them in a broader realm that we establish. In this way we do not need to fall back on representations or deny that the system operates in an environment that is familiar owing to its history of structural coupling.

Perhaps an analogy will clarify this. Imagine a person who has always lived in a submarine. He has never left it and has been trained how to handle it. Now, we are standing on the shore and see the submarine gracefully surfacing. We then get on the radio and tell the navigator inside: "Congratulations! You avoided the reefs and surfaced beautifully. You really know how to handle a submarine." The navigator in the submarine, however, is perplexed: "What's this about reefs and surfacing? All I did was push some levers and turn knobs and make certain relationships between indicators as I operated the levers and knobs. It was all done in a prescribed sequence which I'm used to. I didn't do any special maneuver, and on top of that, you talk to me about a submarine. You must be kidding!"

All that exist for the man inside the submarine are indicator readings, their transitions, and ways of obtaining specific relations between them. It is only for us on the outside, who see how relations change between the submarine and its environment, that the submarine's behavior exists and that it appears more or less adequate according to the circumstances involved. If we are to maintain logical accounting, we must not confuse the operation of the submarine itself and its dynamics of different states, with its movements and changing positions in the environment. The dynamics of the submarine's different states, with its navigator who does not know the outside world, never occurs in an operation with representations of the world that the outside observer sees: it involves neither "beaches" nor "reefs" nor "surface" but only correlations between indicators within certain limits. Entities such as beaches, reefs, or surface are valid only for an outside observer, not for the submarine or for the navigator who functions as a component of it.

What is valid for the submarine in this analogy is valid also for all living systems: (...) for each one of us human beings.

There is another section after this which I will also bring, so they stay together, about behavior and its observation.

Behavior and the Nervous System
What we call behavior in observing the changes of state of an organism in its environment corresponds to the description we make of the movements of the organism in an environment that we indicate. Behavior is not something that the living being does in itself (for in it there are only internal structural changes) but something that we point to. Inasmuch as the changes of state of an organism (with or without a nervous system) depend on its structure and this structure depends on its history of structural coupling, changes of state of the organism in its environment will necessarily be suitable and familiar to it, independently of the behavior or environment we are describing. For this reason, if a behavior as a particular configuration of movements is to appear adequate, it will depend on the environment in which we describe it. The success or failure of a behavior is always defined by the expectations that the observer specifies. If the reader were in the desert and did the same movements and postures that he now adopts in reading this book, his behavior would not only be eccentric but pathologic.

Thus, the behavior of living beings is not an invention of the nervous system and it is not exclusively associated with it, for the observer will see behavior when he looks at any living being in its environment. What the nervous system does is expand the realm of possible behaviors by endowing the organism with a tremendously versatile and plastic structure. This is the topic of the next chapter.

After taking the first hundred pages or so to set the parameters of the book and its contents, the reader feels reasonably assured that they not only know what they are talking about, but how.

[Diane]

The next chapter in the book (p. 142) is called the Nervous System and Cognition. The authors begin by examining the concept of "behavior", and point out that "behavior", or "movement", are not confined only to animals with nervous systems.
In this chapter we wish to examine in what way the nervous system expands the realms of interaction of an organism. We have already seen that behavior is not an invention of the nervous system. It is proper to any unity seen in an environment where the unity specifies a realm of perturbations and maintains its organization owing to the changes of state that these perturbations trigger in it.

We must keep this clearly in mind, for we usually regard behavior as something proper to animals with a nervous system. Moreover, the usual associations with the word "behavior" come from actions such as walking, eating, searching and so forth. If we examine closely what is common to all these activities currently associated with the notion of behavior, we find they all have to do with movement. But movement, whether on land or in water, is not universal to living beings. Among the many forms resulting from natural drift, there are many that show no movement.

Let us consider, for example the plant in Figure 37. The plant is Sagittaria sagittufolia (http://en.wikipedia.org/wiki/Sagittaria_sagittifolia). The authors describe how the leaves are found in one form above water and in another below water. If the water level is artificially raised and lowered to submerge and expose the plant, the plant changes its leaves from one form to the other within a few days. The situation is reversible; it occurs with structural transformations that are quite complex and that have to do with a certain form of differentiation in the several parts of the plant. This is a case we could describe as behavior, for there are structural changes that appear as observable changes in the plant's form to compensate for recurrent disturbances of the environment. This situation, however, is normally described as a change in the plant's development and not in its behavior. Why?

Let us compare the case of the sagittaria with the feeding behavior of an amoeba about to ingest a small protozoan by extending its pseudopods. These pseudopods are protoplasm expansions or digitations that can be associated with changes in the local physicochemical makeup of the cell membrane and matrix. The result is that the protoplasm flows at certain points and pushes the animal in one direction or another, which results in its amoeboid movements. In contrast to what happens with the sagittaria, no one hesitates to describe this situation as behavior.

From our standpoint, it is clear that between both cases tere is a continuity. Both are instances of behavior. It is interesting to note that it is easier for us to call one - and not the other - a case of behavior, only because we can detect movement in the amoeba and not in the sagittaria. That is, there is a continuity between this movement in the amoeba and the great diversity of behaviors of higher animals which we always see as forms of movement. By contrast, the changes in differentiation of the sagittaria seem remote from what we know as movement because of their slowness, and we see it only as a change in form. I can think of other examples. The sunflower almost visibly keeps its "face" turned toward the sun as it passes over. Morning glories respond quickly to sun or to its absence. Star fish move all over the place and have complex behaviors as seen on sped-up footage, but move so slowly in real time they appear stationary. Actually, from the standpoint of the nervous system's appearance and transformation, the possibility of movement is essential. This is what makes the history of movement so fascinating. Exactly how and why are what we are going to see throughout this chapter. But first let us look at general cases from a wider perspective. We shall now consider movement as it appears in varied realms of nature. The authors direct the readers' attention to a graph that depicts the relations of size and speed in nature. Size is graphed vertically and speed horizontally. ..it is evident that regarding the extremes of big and small, both the galaxies and the elemental particles are capable of very fast movement in the order of thousands of miles per second. If we consider large molecules as those which constitute living beings, their movement becomes slower as their size becomes bigger and they move in viscous surroundings formed by other molecules. Thus, there are molecules that contain many of the proteins of our organization which are so large that their spontaneous movement is insignificant when compared with the mobility of smaller molecules.

It is under these circumstances that (as we saw in Chapter 2) autopoietic systems appear; this is made possible by the existence of these many large organic molecules. Once the much larger molecules formed, the curve shows a brisk shift in which the history of cell transformations led to the origin of structures such as flagella or pseudopods, which again allow for considerable movement, because they call into play forces much greater than those of viscosity. Moreover, when multicellular organisms originate, some of them develop - through cell differentiation - much more spectacular locomotive capacities. Thus an impala can run at a speed of many miles an hour, even though it is many times bigger in size than a small molecule that moves (on the average) at the same speed. Metazoa and motile single-cell organisms therefore create a range of movement which, for their size, is unique in nature.

Let us not lose sight, however, of the fact that the appearance of this type of movement is neither universal nor necessary for all forms of living beings. Plants are a fundamental case resulting from a natural drift in which movement is essentially absent as a way of being. Presumably this is related to the fact that plants are maintained through photosynthesis under the following conditions: they have a constant local supply of nutrients and water from the ground, and gases and light from the atmosphere. This allows conservation of adaptation with out the need for large or rapid movements during most of the plant's ontogeny.

To an observer, it is evident that movement poses many possibilities. Many of them are embodied in living beings as a result of their natural drift. Thus, motile organisms base not only their reproduction on movement but also their feeding and modes of interaction with the environment. It is in relation to these living beings in whom natural drift has led to the establishing of motility that the nervous system becomes important. This is what we shall look at now in greater detail.

I think this is a clear and important context the authors have drawn.

1. There are a lot of very "alive" self-organized (autopoeitic) forms out there that have no nervous system, yet exhibit complex behaviors that include movement. (Plants, amoebas)

2. Movement systems, with or without nervous systems, evolve when molecules become too big to move by themselves. (Flagellae, limbs)

3. We cannot, therefore, allow movement and behavior to be conflated with presence or absence of a nervous system.

Next, sensorimotor coordination in single cell organisms.

[Jon Newman]

Hi Diane,

You may be interested in this study.

From bit to it: How a complex metabolic network transforms information into living matter (http://www.biomedcentral.com/1752-0509/1/33)

[Diane]

Thanks Jon! :)

[Diane]

Single-cell organisms do not have a nervous system, yet they coordinate their functions, respond to their environment, eat and eliminate, grow, reproduce, move around etc., all things we associate with the nervous system being necessary to do. How do they do it? Single-cell organisms invented everything (all the life processes) we take for granted, and they didn't have nervous systems! Nervous systems came along once multi-cellularity was already established and sheer bodily size and complexity required faster signalling to achieve life enhancing stability of function.

From p. 147, of Tree of Knowledge: Sensorimotor Coordination in Single-Cell Organisms
Let us return for a moment to the amoeba at the point of engulfing a protozoan. What is happening in this sequence? It can be summed up in this way: the presence of the protozoan generates a concentration of substances in the environment. These substances are capable of interacting with the amoeba membrane, triggering changes in the consistency of the protoplasm which result in the formation of a pseudopod. The pseudopod, in turn, causes changes in the position of the moving animal, thus modifying the number of molecules in the environment which interact with its membrane. This cycle is repeated, and the sequence of movements of the amoeba is therefore produced through the maintenance of an internal correlation between the degree of change of its membrane and those protoplasmic changes we see as pseudopods. That is, a recurrent or invariable correlation is established between a perturbed or sensory surface of the organism and an area capable of producing movement (motor surface) which maintains unchanged a set of internal relations in the amoeba.

Another example can help clarify this idea. The authors point to a figure that shows a type of swimming protozoan with a flagellum, bumping into an obstacle and shifting direction as a result. This flagellum beats in such a way that it is capable of moving the protozoan in its fluid medium or environment. In this particular case, the flagellum beats so that it pulls the cell behind it. In this swimming action, at times the protozoan hits an obstacle. What occurs in that situation? There is an interesting behavior in relation to change of orientation: the flagellum bends as it hits the obstacle. This bending triggers changes in the flagellum's base that is embedded in the cell. This cell, in turn, triggers changes in the cytoplasm that slightly rotate it, so that when the beating begins again, it moves the cell in a different direction. As a result, the protozoan touches the obstacle, bends, then avpoids it. Again, as in the case of the amoeba, what is happening here is that a certain internal correlation is being maintained between a structure capable of admitting certain perturbations (sensory surface) and a structure capable of generating movement (motor surface). The interesting thing about this example is that both the sensory surface and the motor surface are the same; therefore, their coupling is immediate.

Let us consider another example of this coupling between sensory surfaces and motor surfaces. There are single-cell bacteria that have flagella similar in appearance to those of some protozoa... however, these flagella function very differently. Instead of beating as in the other case, they simply remain fixed on their base and rotate, so that they are like a propeller for the bacteria. Moreover, both directions are possible in these rotations. But there is one direction in which the coordination of the rotations results in a clear-cut movement of the bacteria, whereas in the opposite direction of rotation the coordination causes the bacteria simply to tumble about in the same place. It is possible to follow the movements of one of these bacteria under the microscope and see its changes, under different controlled conditions. If the bacterium is placed, for instance, in an environment where a grain of sugar has been put in one corner, we note that the bacterium stops its tumbling behavior, changes the direction of rotation of the flagella and heads for the zone of greatest sugar concentration following the path of its gradient concentration. How does this occur? It happens that in the membrane of the bacterium there are special molecules capable of interacting with the sugar, so that as there is a difference of concentration within a small area around the bacterium, changes take place within it; these changes make the flagellum rotate in a different direction. At each moment, therefore, a stable correlation is again established between the sensory surface and the motor surface of the cell, which gives it a clearly discriminatory behavior as it heads for the zones of greater concentration of certain substances. This is known as chemotaxis.
It is an example of behavior on a single-cell level, many of whose molecular details are known.

Unlike these bacteria, the sagittaria which we mentioned, and other plants, do not have a motor surface that endows them with movement. In fact we find among bacteria some cases that are a sort of compromise between capacity to move and incapacity to move. For instance when Caulobacter is in a very humid environment, it remains fixed to the ground by a plant-like pedestal. During a period of dehydration, however, the bacteria reproduce and new cells grow with a flagellum capable of transporting them to a more humid environment.

Next up - how multi-cells do things.

[Diane]

The next section appears p. 150. It explains what the authors mean by "coupling":

Multicellular Sensorimotor Correlation

We have seen in the foregoing examples that movement (behavior) in single-cell organisms is based on a very specific correlation between their sensory surfaces and their motor surfaces responsible for movement. We have also seen that this correlation occurs through processes inside the cell, that is, through metabolic transformations proper to the cell unity. What happens in the case of multi-cellular organisms?

Let us examine through an example. (Hydra) belong to a group of coelenterates, an ancient lineage of animals made up of a double layer of cells in the form of a vase. Tentacles at its edge permit it to move in the water and capture other animals, which it takes in and digests by secreting digestive fluids. If we look at the cell structure of this animal, we see a double layer: one facing inside and the other outside. One of these two surfaces seems to have a certain cell diversity. Thus, there are cells with little darts. On being touched, these cells shoot out their projectiles. Other cells possess vacuoles capable of secreting digestive liquids on the inside. We also find in the hydra some motor cells that possess contractile fibres, positioned longitudinally and radially on the wall of the animal. When these muscle cells contract in various combinations, they cause the animal to move in different ways. This is exactly the same set-up as in the human gut tube, by the way, which can contract either longitudinally (moving food along) or radially (pinching off a chunk of food to work on absorbing), depending which set of smooth muscle cells contract. See? We haven't got much of anything in our bodies that wasn't already invented ages ago by other organisms ;). Our smooth muscle system (driven by the enteric nervous system which is mostly reflexive and self-referential) within the gut tube can't physically "move" the gut tube itself from point A to point B, because it is fastened inside the body cavity to various attachment points, but it can move along the contents thereof. To produce a coordinated action between, say, the muscle cells of the tentacles and the secretory cells on the outside, evidently there must be some type of coupling between these cells. It is not enough for them to be simply arranged in a double layer.

To understand how this coupling takes place, we have to look more carefully at what exists between both cell layers. There we find a peculiar type of cell, with prolongations that extend for a considerable length within the animal. These cells are peculiar in that, through their prolongations, they establish contact with topographically distinct cellular elements of a metozoan. These cells are nervous cells or neurons in their most simple and primitive form. The hydra has one of the simplest forms of nervous system known. It is made up of a network that includes these particular cells, as also receptors and effectors. On the whole, the hydra's nervous system is like a maze of interconnections that extends to all parts of the animal through the space between the cells. In this way, it causes an interaction of the sensory and motor elements that are distant.

Thus we have, complete in all its details, the same situation we had in the case of single-cell behavior: a sensory surface (in this case, sensory cells), a motor surface (in this case, muscle and secretory cells), and a system of coordination between both surfaces (the neuronal network). And the hydra's behavior (feeding, flight, reproduction etc.) results from the different ways in which these two surfaces (sensory and motor) are dynamically related, via the interneuronal network, to constitute the nervous system. The neuronal network in a hydra and the enteric network in our own gut tubes have much similarity, including a non-local, distributed quality, and (in vertebrates) a huge amount of independence from the rest of the nervous system.

Next, neuronal structure.

[Diane]

The authors go on to explain what makes nerve cells different from other cells, why they belong in a separate grouping. From page 153: Neuronal Structure
What distinguishes neurons is their cytoplasmic ramifications in specific forms which extend for enormous distances, reaching tens of millimeters in the largest ones. I don't think they are talking about vertebrates yet. A human neuron can be a meter long. A giraffe neuron, a blue whale neuron... I doubt they are thinking of these animals here. This universal neuronal characteristic, present in all organisms with a nervous system, determines the specific way in which the nervous system participates in the second-order unities that it integrates by placing in contact cellular elements located in different parts of the body. We cannot disregard all the exquisite transformations required for the growth of a cell initially by measuring a few millionths of a millimeter into specific forms with ramifications that can reach tens of millimeters in an expansion of several orders of magnitude. The authors point to a figure showing an image of a neuron whose axon is neatly folded several times and still takes up two pages. It is therefore through their physical presence that neurons couple, in many different ways, cellular groups which otherwise could be coupled only through the general circulation of internal substances of the organism. The physical presence of a neuron enables substances to be transported between two regions through a very specific path that does not affect the surrounding cells and their local delivery. The particular feature of connections and interactions that the neuronal forms make possible is the master key to the operation of the nervous system.

There are many types of reciprocal influences between neurons. Best known of all is an electrical discharge that propagates along the neuronal prolongation called the axon, at a wildfire speed. That is why the nervous system is often said to be an organ that functions on the basis of electrical exchanges. This is only partly true, however, for neurons interact not only through electrical exchanges but also and in a constant way through substances which are transported inside the axon and which, released (or picked up) at the terminals, trigger in the neurons, in the effectors or in the sensors to which they are connected, changes in differentiation and growth.

With what types of cells do neurons connect? Actually they connect with almost all cell types within an organism; however, they connect with their expansions, mostly with other neurons. These nervous expansions are in turn, very specialized; they are known as dendrites and axon terminals. Both in these zones and in the cell bodies, contacts called synapses are established. A synapse is the point where mutual influences are effectively produced between a neuron and that with which it makes contact. Synapses, therefore, are the effective structures that enable the nervous system to carry reciprocal influences between distant cell groups.

Although the overwhelming majority of synaptic contacts in the nervous system are between neurons, these neurons form synapses with many other cell types in the organism. Such is the case of the cells that we have been calling collectively the sensory surface. In the hydra, for instance, this would include all the cells capable of responding to specific perturbations, either of the environment (such as the spearlike cells) or of the organism itself (such as the chemoreceptor cells). Likewise, there are neurons that connect with cells of the motor surface, especially the muscles, in a very precise pattern. In short, the neuronal system is embedded in the organism through many contacts with varied cellular classes operating as a network of precise neuronal interactions together with the cells of the sensory and motor surfaces. I must admit, I never really thought about the nervous system this way - as the surface being either motor or sensory, not the neuron itself. It's a very interesting way to look at it. It turns all neurons into effectors.

[bernard]

Here is a (French) image about transports that occur in axons.

[Diane]

Interesting - the bottom image looks like the mitochondria actually move up and down the axon. I never have seen anything before suggesting that. I thought mitchondria stayed in the soma. This tells me I have a great deal to learn about neurons and what makes them tick.

[bernard]

Nat Methods. (javascript:AL_get(this, 'jour', 'Nat Methods.');) 2007 Jul;4(7):559-61. Epub 2007 Jun 10.
Related Articles (http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed&DbFrom=pubmed&Cmd=Link&LinkName=pubmed_pubmed&LinkReadableName=Related%20Articles&IdsFromResult=17558414&ordinalpos=1&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVAbstract), Links (javascript:PopUpMenu2_Set(Menu17558414);)
http://www.ncbi.nlm.nih.gov/corehtml/query/egifs/http:--www.nature.com-images-lo_npg.gif (http://www.ncbi.nlm.nih.gov/entrez/utils/fref.fcgi?PrId=3094&itool=Abstract-def&uid=17558414&db=pubmed&url=http://dx.doi.org/10.1038/nmeth1055)
Imaging axonal transport of mitochondria in vivo.

Misgeld T (http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed&Cmd=Search&Term=%22Misgeld%20T%22%5BAuthor%5D&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVAbstract), Kerschensteiner M (http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed&Cmd=Search&Term=%22Kerschensteiner%20M%22%5BAuthor%5D&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVAbstract), Bareyre FM (http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed&Cmd=Search&Term=%22Bareyre%20FM%22%5BAuthor%5D&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVAbstract), Burgess RW (http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed&Cmd=Search&Term=%22Burgess%20RW%22%5BAuthor%5D&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVAbstract), Lichtman JW (http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed&Cmd=Search&Term=%22Lichtman%20JW%22%5BAuthor%5D&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVAbstract).

Department of Molecular and Cellular Biology, Harvard University, 7 Divinity Avenue, Cambridge, Massachusetts 02138, USA. thomas.misgeld@lrz.tu-muenchen.de

Neuronal mitochondria regulate synaptic physiology and cellular survival, and disruption of their function or transport causes neurological disease. We present a fluorescence method to selectively image mitochondrial dynamics in the mouse nervous system, in both live mice and acute explants. We show that axon damage and recovery lead to early and sustained changes in anterograde and retrograde transport. In vivo imaging of mitochondria will be a useful tool to analyze this essential organelle.

Publication Types:
Research Support, N.I.H., Extramural (javascript:AL_get(this, 'ptyp', 'Research Support, N.I.H., Extramural');)
Research Support, Non-U.S. Gov't (javascript:AL_get(this, 'ptyp', 'Research Support, Non-U.S. Gov\'t');)
PMID: 17558414 [PubMed - indexed for MEDLINE]

[Diane]

The next section is about the architecture of the nervous system. From p. 157: The interneuronal network
This basic architecture of the nervous system is universal and valid not only for the hydra but also for higher vertebrates including human beings. The sole difference lies not in the fundamental organization of the network that generates sensorimotor correlations but in the form in which this network is embodied through neurons and connections that vary from one animal species to the other. Indeed, a survey of the neuronal types found in the nervous systems of animals shows an enormous diversity. Some of these neuronal varieties are shown in Figure 46. This figure shows the branching pattern of four neurons- a bipolar retinal cell, a motoneuron of the spinal medulla, a pyramidal cell of a mammal's cerebral cortex, and a mitral cell in the olfactory bulb. Moreover, if we keep in mind that the human brain has more than 1010 and perhaps more than 1011 neurons (tens of billions) and that each one of them receives many contacts with other neurons and connects, in turn, with many cells, the combinations of possible interactions are more than astronomical. Butler refers to this astronomical number in his book, Sensitive Nervous System. But we emphasize: the basic organization of this immensely complicated human nervous system follows essentially the same logic as in the humble hydra. In the series of transformations of lineages that go from the hydra to mammals, we meet with designs that are variations on the same theme. In worms for instance, the nervous tissue understood as a network of neurons has been separated like a compartment inside the animal, with nerves along which pass connections that come and goo from the sensory surfaces and motor surfaces.

Each variation in the animal's motor state will become the product of a certain pattern of activity in certain groups of neurons connected to the muscles (motoneurons). This motor activity however, generates many changes in the sensory cells located in the muscles, in other parts of the body, and on the surface of contact with the environment as also in the motoneurons. This occurs in a process brought about by means of changes in the network of interposed neurons, or interneurons, which interconnects them. In this way there is a continuous sensorimotor correlation determined and mediated by the pattern of activity of this interneuronal network. Since there can be a practically unlimited number of possible states within this network the possible behaviors of the organism can also be practically unlimited.

This is the key mechanism whereby the nervous system expands the realm of interactions of an organism: it couples the sensory and motor surfaces through a network of neurons whose pattern can be quite varied. The mechanism is eminently simple. Once established however, it permits many different realms of behavior in the phylogeny of metazoa. In fact, the nervous systems of varied species differ only in the specific patterns of their neuronal networks.

Thus, in humans, some 1011 (one hundred billion) interneurons interconnect some 106 (one million) motoneurons that activate a few thousand muscles with some 107 (ten million) sensory cells distributed as receptor surfaces throughout the body. Between motor and sensory neurons lies the brain, like a gigantic mass of interneurons that interconnects them (at a ratio 10:100,000:1) in an everchanging dynamics.
I've got to say, this clear insight into nervous system functionality, and their way of describing it, is brilliant. Look at that ratio! 10 to 100,000 to 1. There are 10 sensory neurons for every 1 motoneuron, and their relationship is either enhanced or inhibited by 100,000 other neurons in between. That's a lot of potential variation inherent in the system, for what we do as therapists. This is what we treat, regardless of whatever bit of structure we may "think" or "believe" we are treating.

The next part is a bit more technical.

[Jon Newman]

Hi Diane,

I appreciate you posting these. I've put the book on my list. Unfortunately my list is not in dynamic equilibrium but I think this one is going to move to a place closer to the top.

[Diane]

You're welcome Jon. The book is 10 years old by now, but still very fresh - to me anyway.
Here is a link to the paper (http://www.somasimple.com/forums/showthread.php?t=4709) Bernard mentioned.

[Jon Newman]

In my internet travels I discovered that it is on the "recommended reading" list for the neuroscience program at UCSD (University of California San Diego.)

[Diane]

This morning I had my first opportunity to tell a patient about the ratio 10:100,000:1 as part of her "pain education".

She got it instantly as she is a code-writer/computer programmer. She said, "It's exactly the same as what I do for a living. I have to write 100,000 lines of basic code, which I can access through inputting 10 lines of code, and out comes one line." I didn't get what she meant at all, but I'm glad she understood what I was saying.

I also shared my little analogy, how-the-S1M1-representational-map-is-like-photoshop, "...and areas that are well-represented have.." , whereupon she broke in and said, "it's like the well-represented areas like lips and fingers have a thousand pixels per inch whereas the back has 72?"

And I said, "exactly, but more like 4 or 5 ..." but I was pretty sure she could likely have explained it to me better than I ever could to her were our roles reversed, and that she would be able to go back to work and tell a better story to her workmates about her treatment instead of just saying it was "kinda faith-healey but it worked."

[Diane]

Continuing on from post 11 (http://www.somasimple.com/forums/showpost.php?p=42452&postcount=11), p. 160. The authors point the reader's attention to a figure depicting a simple sensory motor reflex arc:
Fig. 47 shows a sketch of a skin sensory neuron capable of responding (electrically) to an increase of pressure at that point. What causes the activity? Well, that neuron connects to the inside of the spinal medulla, where it makes contact with many interneurons. Among them, some make direct contact with a motoneuron capable, by its activity, of triggering the contraction of a muscle. This results in a movement. This movement results in a change of sensory activity by decreasing pressure on the sensory neuron; this reestablishes a certain reciprocal relation between the sensory and motor surfaces. Described from the outside, what happened is that the hand was withdrawn from a painful stimulus. Described from the nervous system, what happened is that a certain sensorimotor correlation was maintained within the nervous system through a neuronal network. Now, since many other neurons that originate in other parts of the nervous system (e.g., at the cortex) may influence the activity of the motoneurons, the behavior of leaving the hand under the excess pressure is now possible. But this would mean establishing a new internal balance, involving other neuronal groups more diverse than in the first case, where the hand was withdrawn.

Let us try to imagine, from particular situations like the previous example of painful pressure, an organism that functions normally. At each moment we shall find that the nervous system is operating according to many internal cycles of neuronal interactions (like that of the motoneurons and sensory fibres of the muscle) in never ending change. Modulating this immense activity are those changes in the sensory surface due to perturbations independent of the organism (such as pressure on the skin). As observers we are used to focusing our attention on what is more apparent to us, that is, external perturbations, and we readily believe that this is the determining factor. These external perturbations, however, as we just said, can only modulate the constant coming and going of internal balances of sensorimotor correlations. Thank you, Maturana and Varela, for saying this so cogently and clearly. Until manual therapists learn to look at manual therapy from the nervous system's perspective, we'll be forever dogged by heroics (i.e., the vanity of supposing that what we do has any other sort of effect whatsoever), and balnibarian-esque science projects that serve to reinforce the heroic perspective, such as, "Let's pretend that when we press here, we are moving bone, then let's try to show that when we push it in x manner, there will always be y response. Then we can merrily divide the whole patient population into subgroups of those who will respond favorably and those who won't", instead of just understanding how the system works from the system's perspective, and trying to help people whose system seems to be at odds with itself.

This is an important notion that we can illustrate by what happens in the visual system. We commonly think that visual perception is a certain operation on the retinal image, whose representation will then be transformed inside the nervous system. This is the representationist approach to the phenomenon. This approach to the visual phenomenon, however, is dispelled once we realize that for each neuron on the retina projected to our visual cortex via the so-called lateral geniculate nucleus (LGN), there are hundreds of neurons from other zones of the nervous system, including other cortical areas that project to the LGN. Thus, the LGN is not simply a relay station for retinal projections to the cerebral cortex since many fibres from other parts of the brain converge upon it and influence whatever comes out of it toward the visual cortex...one of the structures affecting what happens in the LGN is the very same visual cortex to which the cells of the LGN project. That is, both structures are interrelated through reciprocal influences and not in a simple sequential way.

It is enough to contemplate this structure of the nervous system (even though we cannot know much in detail about the relations of activity that occur from moment to moment) to be convinced that the effect of projecting an image on the retina is not like an incoming telephone line. Rather it is like a voice (perturbation) added to many voices during a hectic family discussion (relations of activity among all incoming convergent connections) in which the consensus of actions reached will not depend on what any particular member of the family says.

[Diane]

The next section (p. 163) deals with operational closure. This is a very important concept for manual therapists to get, in the first place, and second of all, to thereafter respect. It has to do with accepting the idea that the nervous system is a closed loop, a functional circularity.

Operational Closure of the Nervous System

We said that behavior is a description an observer makes of the changes of state in a system with respect to an environment with which that system interacts. We said also that the nervous system does not invent behavior, but expands it dramatically. Let us clarify what we mean by this word "expands." It means that the nervous system emerges in the phylogenetic history of living beings like a network of special cells (neurons), which is embedded in the organism in such a way that it couples points in the sensory surfaces with points in the motor surfaces. Thus, with a network of neurons coming between this coupling, the field of possible sensorimotor correlations of the organism is increased and the realm of behavior is expanded.

It is now clear that the sensory surface includes not only those cells that we see externally as receptors capable of being perturbed by the environment, but also those cells capable of being perturbed by the organism itself, including the neuronal network. Thus, for instance, there are chemoreceptor cells in some arteries capable of being specifically modified by changes in the oxygen concentration of a vertebrate's blood. These cells, in turn, modify certain neurons that contribute by their change of activity to changes of state in the entire network leading to changes in the rhythm of activation of respiratory muscles, which thus affect the oxygen level in the blood. Thus the nervous system participates in the operation of a multicellular (organism) as a mechanism that maintains within certain limits the structural changes of the organism. This occurs through multiple circuits of neuronal activity structurally coupled to the medium. In this sense, the nervous system can be characterized as having operational closure. In other words, the nervous system's organization is a network of active components in which every change of relations of activity leads to further changes of relations of activity. Some of these relationships remain invariant through continuous perturbation both due to the nervous system's own dynamics and due to the interactions of the organism it integrates.

In other words, the nervous system functions as a closed network of changes in relations of activity between its components. Time to interrupt and mention yet again the book Rhythms of the Brain (http://www.amazon.com/Rhythms-Brain-Gyorgy-Buzsaki/dp/0195301064) by György Buzsáki (http://www.somasimple.com/forums/showthread.php?t=4227). The entire book is a well written and heavily-footnoted explanation of how the entire system keeps itself going via oscillations that intersect one another. Back to Tree of Knowledge:
Thus, when we experience excessive pressure in any part of the body, as observers we can say: "Aha! The contracting of this muscle will cause me to lift my arm." But from the standpoint of the operation of the nervous system as such (like the case of our friend in the submarine), what occurs is only the constant maintenance of certain relations between sensory and motor elements that were temporarily perturbed by outside pressure. The internal relationship maintained in this case is relatively simple: it is a balance between sensory activity and muscle tone. As to what determines the balance of muscle tone in relation to the rest of the nervous system's activity, it is hard to say in a few words. But, as a rule, all behavior is an outside view of the dance of internal relations of the organism. Finding out in each case the precise mechanisms of those neuronal coherences is the task the researcher faces.

What we said shows that the operation of the nervous system is wholly consistent with its forming part of an autonomous unity in which every state of activity leads to another state of activity in the same unity, because its operation is circular, or in an operational closure. The nervous system, therefore, by its very architecture, does not violate but enriches the operational closure that defines the autonomous nature of the living being. We begin to see clearly the ways in which the very process of cognition is necessarily based on the organism as a unity and on the operational closure of its nervous system; hence it follows that all knowing is doing as sensory-effector correlations in the realms of structural coupling in which the nervous system exists.

As human primate social groomers, we are permanently on the outside of this functional circularity, this operational closure, trapped each in our own circularity and operational closure. The very idea that we can actually affect the body of another person is sheer hubris, and all treatment constructs based on such an "heroic" notion are pure perceptual fantasy/conceptual hallucination. This includes everything from CST to SMT and all that lies in between. If we need to visualize some-thing in order to treat effectively (and I'm the first to admit I still do), I propose that a construct based on peripheral nerves, specifically the cutaneous ones, are less a lie or perceptual fantasy than ones based on deeper-lying non-neural structures are. This is how I get through my treatment day. At least I know it's a lie, a construct, a "let's pretend".. most PTs act as if the constructs they use were the literal truth.

Next up, plasticity.

[Diane]

Before we get to plasticity, I want to bring forward the content in a sidebar on page 169. The authors discuss why caution must be exercised in comparisons of computers and brains. The Brain and the Computer

It is interesting to note that the operational closure of the nervous system tells us that it does not operate according to either of the two extremes: it is neither representational nor solipsistic.

It is not solipsistic, because as part of the nervous system's organism, it participates in the interactions of the nervous system and its environment. These interactions continually trigger in it the structural changes that modulate its dynamics of states. In fact, this is the basis of why, as observers, we see animal behavior in general as being in line with its circumstances and why animals do not behave as though they were following their own leader independently of the environment. This is so despite the fact that, for the operation of the nervous system, there is no inside or outside, but only maintenance of correlations that continuously change (like the indicator instruments in the submarine we used as an example).

Nor is it representational, for in each interaction it is the nervous system's structural state that specifies what perturbation are possible and what changes trigger them. It would therefore be a mistake to define the nervous system as having inputs or outputs in the traditional sense. What? Say again? Forget inputs and outputs? This would mean that such inputs or outputs are part of the definition of the system, as in the case of a computer or other machines that have been engineered. To do this is entirely reasonable when one has designed a machine whose central feature is the manner in which we interact with it. The nervous system (or the organism), however, has not been designed by anyone; it is the result of phylogenetic drift of unities centered on their own dynamics of states. What is necessary, therefore, is to recognize the nervous system as a unity defined by its internal relations in which interactions come into play only by modulating its structural dynamics, i.e., as a unity with operational closure. In other words, the nervous system does not "pick up information" from the environment, as we often hear. On the contrary, it brings forth a world by specifying what patterns of the environment are perturbations and what changes trigger them in the organism. The popular metaphor of calling the brain an "information-processing device" is not only ambiguous but patently wrong. I think this means, the nervous system is completely in charge of what it pays attention to, what it will allow to perturb it/its organism.

[Diane]

From p. 166: Plasticity
Several times we mentioned the fact that the nervous system is a system in continuous structural change, that is, it has plasticity. Indeed, this is a basic dimension in its participating in the makeup of an organism. In effect, as a result of this structural plasticity, the nervous system, through its sensory and effector organs in the interactions of the organism that select its structural change, participates in the structural drift of the organism with conservation of its adaptation.

Now, the structural change of the nervous system does not normally occur as something radical in its broad lines of connectivity. These, on the whole, are invariant and generally they are the same in all individuals of one species. Between the fertilized zygote and the adult, in the process of development and cell differentiation, as the neurons multiply they begin to branch out and connect according to an architecture proper to the species. Exactly how this occurs by processes of exclusive local determination is one of the most interesting puzzles of modern biology.

Where do structural changes occur, therefore, if not in the broad lines of connectivity? The answer is that they occur, not in the connections that unite groups of neurons but in the local characteristics of those connections. That is to say, changes occur in the final ramifications and in the synapses. There molecular changes result in changes in the efficiency of the synaptic interactions that can modify drastically how the entire neuronal network functions.

For instance let us picture the following experiment. We locate one of the big muscles that activate the leg of a mouse, isolating the nerve that descends from the spinal medulla and innervates the muscle. We then cut the nerve and allow the animal to recuperate. After some time, we reopen the animal and examine the muscle. We will find that it is atrophied and shortened. But we did not alter its ali(gn)ment and blood supply. All we did was cut the electric and chemical traffic that normally exists between the muscle and the connecting nerve. If we allow the nerve to grow again and reinnervate the muscle that muscle will recuperate and the atrophy will disappear. Other experiments show that something similar occurs between many (if not all) neuronal elements that make up the nervous system. The level of activity and the chemical traffic between two cells - in this case, a muscle fibre and a neuron - modulate the efficiency and mode of interaction between them during their continuous change. By cutting a nerve we see this dynamic feature in a dramatic way.

The plasticity of the nervous system lies in the fact that the neurons are not connected as though they were cables with their respective plugs. The points of interaction between the cells are zones of delicate dynamic balance modulated by a great number of elements that trigger local structural changes, and that are produced as a result of the activity of those cells and of other cells whose products are released into the blood flow and wash the neurons. It is all part of the dynamics of interactions of the organism in its environment.

There is no known nervous system that does not show some degree of plasticity. But plasticity seems to be much more limited in certain organisms, for example, among insects, in part because they have fewer neurons and are smaller in size. Hence, the phenomenon of structural change manifests itself with vigor among vertebrates and particularly among mammals. Thus, there is no interaction and there is no coupling without consequence for the operation of the nervous system as a result of the structural changes triggered in it. We human beings in particular are modified by every experience, even though at times the changes are not wholly visible.

This we know mostly through observation of behavior. We do not have a clear picture today of structural changes in the nervous system of vertebrates involved in this plasticity. Nor do we have a clear description of how this constant transformation of the mode of neuronal interaction (that occurs in the ontogenic structural drift of the organism) is coupled to ongoing behavior. Again, this is one of the most significant areas of research in neurobiology today.

But whatever may be the precise mechanisms that come into play in this constant microscopic transformation during the interactions of the organism, such changes can never be localized nor seen as anything proper to each experience (e.g., one will never find the record of a dog's name inside its head). This cannot be, first of all because the structural changes triggered in the nervous system are necessarily distributed owing to changes of relative activity in a neuronal network. Second, because the behavior of responding to a name is a description that an observer makes of certain actions that result from certain sensorimotor patterns which, by dint of their internal operations, involve (strictly speaking) the entire nervous system.

The plastic splendor of the nervous system does not lie in its production of "engrams" or representations of things in the world; rather it lies in its continuous transformation in line with transformations of the environment as a result of how each interaction affects it. From the observer's standpoint, this is seen as proportionate learning. What is occurring, however, is that the neurons, the organism they integrate, and the environment in which they interact operate reciprocally as selectors of their corresponding structural changes and are coupled with each other structurally: the functioning organism, including its nervous system, selects the structural changes that permit it to continue operating, or it disintegrates.

To an observer, the organism appears as moving proportionately in a changing environment; and he speaks of learning. To him, the structural changes that occur in the nervous system seem to correspond to the circumstances of the interactions of the organism. In terms of the nervous system's operation, however, there is only an ongoing structural drift that follows the course in which, at each instance, the structural coupling (adaptation) of the organism to its medium of interaction is conserved.

I'm thinking of Ian's post (http://www.dericbownds.net/I_illusion_web/I_illusion_web.html) this morning on the Deric Bownds thread (http://www.somasimple.com/forums/showthread.php?p=42488#post42488), containing a link to his essay, the "I" Illusion (http://www.dericbownds.net/I_illusion_web/I_illusion_web.html). It contains a line image depicting the unconscious brain interacting with itself, sending info forward such that the "conscious" part of the brain the illusion that "it" is acting outward into the environment. A very simple image that encompasses a great deal.

[Jon Newman]

Hi Diane,

I'm going to interject a podcast about the tree of life into your thread exploring the tree of knowledge, perhaps creating a forest for the trees if you will.

Carl Zimmer (http://scienceblogs.com/loom/) was recently featured on NPR's All Things Considered (http://www.npr.org/templates/story/story.php?storyId=16809338)

Back to you.

[Diane]

From p. 171, Tree of Knowledge: Innate Behavior and Learned Behavior
We have said many times - lest we forget - that all behavior is a relational phenomenon that we, as observers, witness between organisms and environment. An organism's range of possible behavior, however, is determined by its structure. This structure specifies its realms of interaction. For this reason, every time in the organisms of one species certain structures develop independently of the peculiarities of their histories of interaction, it is said that those structures are genetically determined and that the behavior they make possible (if any) is instinctive. When an infant shortly after being born suckles its mother's breast, it does so independently of whether it was born by natural delivery or caesarian section, or whether it was born in a highly efficient urban hospital or on a remote island.

But if the structures that make possible a certain behavior in members of one species develop only if there is a particular history of interactions, it is said that the structures are ontogenic and the behavior is learned. The authors mention a previous chapter that described a "wolf girl" who did not interact with humans until after important developmental milestones had been missed. She never learned to run on two feet - instead she preferred to run on all fours. Even in something as elemental as running, we depend on a human context that surrounds us like the air we breathe.

Note well that innate behavior and learned behavior are, as behaviors, indistinguishable in their nature and in their embodiment. The distinction lies in the history of the structures that make them possible. Therefore, our classifying them as one or the other depends on whether or not we have access to the pertinent structural history. We cannot make that distinction by observing the operation of the nervous system in the present.

It is important to realize that we tend to consider learning and memory as phenomena of changing conduct related to "taking in" or receiving something from the environment. This presupposes that the nervous system functions with representations. We have already seen that this supposition obscures and complicates tremendously our understanding of the cognitive processes. Everything we have said points to learning as an expression or structural coupling, which always maintains compatibility between the operation of the organism and its environment. When we as observers look at a sequence of perturbations, for which the nervous system compensates in one of many possible ways, it seems to us that it internalizes something of the environment. But, as we know, to make this description would undermine our logical accounting: as though something useful to us for communication between observers were an operational element of the nervous system. To describe learning as an internalization of the environment confuses things by suggesting that in the structural dynamics of the nervous system there are phenomena that exist only in the descriptive realms of some organisms, like ourselves, capable of language.

Here is the last part of the chapter, p. 173: Knowledge and the Nervous System
In the previous chapter we talked about realms of behavior. In this chapter we have talked about the basic organization of the nervous system. Thus, we have come ever closer to those everyday phenomena that we call acts of knowledge. We are now ready to refine our understanding about what is meant when we say that an act is cognitive.

If we reflect a moment on what criterion we are using to say whether someone has knowledge, we will see that what we are seeking is an effective action in the realm where an answer is expected. That is, we are expecting as effective behavior in a context that we specify with our question. Thus, two observations made about the same subject, under the same conditions, but with different questions, can render different cognitive values about the behavior of the subject.

A story from real life illustrates this clearly. A university student was told during an examination: "Calculate the height of the university tower by using this altimeter." The student took the altimeter and a long string, went to the top of the tower, tied the altimeter to the string, and dropped it very carefully to the foot of the tower. He then measured the length of the cord that extended to the bottom. It measured 30 meters and 40 centimeters. The professor, however, considered his answer wrong. But the student was given another chance. Again the professor told him: "Calculate the height of the university tower with this altimeter." The young student took the altimeter, went to the garden near the tower with a goniometer. Standing at a certain distance from the tower, he used the length of the altimeter to triangulate the tower. He calculated 30 meters and 15 centimeters. The professor again said he was wrong. (...) The student used six different procedures to calculate the tower's height with the altimeter, without ever using the altimeter. Evidently, from a certain standpoint, the pupil revealed much more knowledge than he was asked for. From the standpoint of the professor's question, his knowledge was inadequate.

Note well, therefore, that the evaluation of whether or not there is knowledge is made always in a relational context. In that context, the structural changes which perturbations trigger in an organism appear to the observer as an effect upon the environment. It is in reference to the effect the observer expects that he assesses the structural changes triggered in the organism. From that standpoint, every interaction of an organism, every behavior observed, can be assessed by an observer as a cognitive act. In the same way, the fact of living - of conserving structural coupling uninterruptedly as a living being - is to know in the realm of existence. In a nutshell: to live is to know (living is effective action in existence as a living being).

In principle this is sufficient to explain the nervous system's participation in all cognitive dimensions. But if we wish to understand the nervous system's participation in all the particular forms of human knowledge, of course we would have to describe all the specific and concrete processes involved in generating each human behavior in its different realms of structural coupling. For that, it would be necessary to look closely at the operation of the nervous system in human beings, in full detail; but that is beyond the scope of this book.

To sum up: the nervous system participates in cognitive phenomena in two complementary ways. These have to do with its particular mode of operation as a neuronal network with operational closing as part of a metacellular system.

The first, and most obvious, is through expanding the realm of possible states of the organism that arises from the great diversity of sensorimotor patterns which the nervous system allows for and which is key to its participation in the operation of the organism.

The second is through opening new dimensions of structural coupling for the organism by making possible in the organism the association of many different internal states with the different interactions in which the organism is involved.

The presence or absence of a nervous system determines any discontinuity between organisms that have a cognition relatively restricted and those that are open-ended, as in human beings. To point up its key importance, to the symbol that designates an autopoietic (cellular or multicellular) unity: The authors show a small picture of a circle revolving counterclockwise depicted by an arrow, beneath, a downward arrow and an upward arrow depicting involvement with the environment, in turn depicted by a wavy line below. we must now add the presence of a nervous system, which functions also with operational closure but as an integral part of the organism. We diagram it succinctly as follows: The next diagram shows a horizontal circle inside a vertical circle, both revolving counterclockwise. The interactional arrows and the wavy line are still there. In an organism with a nervous system rich and vast as that of human beings, its realms of interactions open the way to new phenomena by allowing new dimensions of structural coupling. In human beings this makes for language and self-consciousness.

I highlighted the bits that seem to me to have to do with treatment. From our treatment perspective, it only looks like we have an effect on the "environment" or patient. We go to great lengths to measure this as best we can using a variety of methods. But what if we are wrong from the start? We can't have any direct effect on a closed operational system other than via inherent plasticity of the system, over which we have no control. We just carry on and hope for the best, as if we weren't two steps removed from the ultimate chaotic outcome of whatever "we" provide to that nervous system as "environmental perturbation" from its standpoint.

Quite the shell game we are conducting with ourselves in this profession, being forced to perform our little science projects in order to be able to continue to perform ordinary careful human primate social grooming. How ever did we all get sucked into this bad movie of trying to prove what we do has any sort of measurable effect? Wait - I know, our mirror neurons were/are mesmerized by the medical model we have worked hard to copy, and we fear society not wanting to pay for our work via insurance structure. Our own version of a razor's edge except we've got no control of the steering wheel of the ship we're riding in, and we are heading directly toward the whirlpool. Maybe it won't be all bad, getting all wet. Quite a few of us already have had practice swimming underwater.

[Diane]

The next chapter is about "third-order structural coupling" or, what happens when two organisms interact; When this happens, the co-drifting organisms give rise to a new phenomenological domain, which may become particularly complex when there is a nervous system. You don't say!
Whew. :shade: :clap2:

[Diane]

It's time to start a new thread on this book, and the widening circles I'm noticing that include neurophenomenology (http://72.14.253.104/search?q=cache:yjVDMBk_uoEJ:www.janushead.org/9-1/Andrieu.pdf+neurophenomenology&hl=en&ct=clnk&cd=9&gl=ca&lr=lang_en|lang_es), and something else called radical constructivism (http://www.univie.ac.at/constructivism/).