Application of Control Mastery Theory to an Understanding of Mammalian Sleep--Part 1

• Psychotherapy is a science by Joe Weiss, 5/15/97
  
  

I couldn't agree more, as the following text indicates.

INTRODUCTION

What follows is a concept of mammalian sleep that indicates the possible applicability of Control Mastery Theory (CMT) to sleep research. This concept is described in several installments relating to: an interpretation of several of the physiological concomitants of normal human sleep and an analysis of Freud's dream of Irma's injection in terms that make much use of the specifics of CMT. The material presented in the first two installments is dated and not adequately verified experimentally, and as such is intended merely to be suggestive of this possibility.

Mammalian sleep presumably serves many functions, each of which adds to the parade of physiological events sleep researchers monitor during sleep, making it problematical to tease apart the various contributions. It is assumed here that because humans are the most adaptable of all animals, one may expect that learning plays a relatively great role in determining the progression of physiological events during human sleep and that, therefore, to the first approximation, it may be possible to understand this progression in terms of a CMT-derived adaptive function alone.

Ideally a concept of sleep should be able to relate cognitive processes to neurological events on a microscopic scale. That is, it should be possible to differentiate the activities of small numbers of neurons. The concept of sleep presented here, however, is not capable of such fine detail. Rather, its interpretations will be restricted, for the most part, to the activities of macroscopic event clusters involving large neuronal masses.

This approach may be defended in terms of an analogous situation in physics. Ideally one should strive to understand the physical and chemical properties of a gas, liquid, or solid in terms of an application of statistical analysis to the properties and interactions of a material's constituent atoms. Before the advent of statistical mechanics, however, physicists and chemists sought such an understanding in terms of macroscopic variables, using the theory of thermodynamics. Thermodynamics was of great utility then and is used to great benefit even today. Therefore, one should not necessarily be quick to dismiss as valueless a concept of sleep derived in terms of macroscopic concepts.

THE RELATIONSHIP BETWEEN LEARNING AND SLEEP

The progression of dreamlike thoughts and dreams that characterize a typical night of human sleep are seen here has facets of a single ongoing process prompted as an adaptive response to the events of the preceding waking interval. CMT has described the nature and intent of human dreams and dreamlike elements as follows (Weiss, J., How Psychotherapy Works, pp. 142-143, 1993):

"...a person, in his dreams as in his conscious waking life, thinks about his reality and attempts to adapt to it. A person's dreams are products of normal (albeit unconscious) thoughts, and they express his attempts at adaptation. He produces dreams in an effort to deal with current concerns that he has not resolved by waking thoughts, either because these concerns are too overwhelming, because he is hampered in his thinking about them by his pathogenic beliefs, or because he has not had time to think about them. A person may sometimes reveal more self-knowledge and may see things more clearly in his dreams than in his waking life.

"In his dreams a person may assess situations and develop plans for dealing with them much as he does in waking life. He may alert himself to a problem that he has overlooked, make a resolution, remind himself of a new insight, console himself for a loss, or reprimand himself for a misdeed. He may prepare for an upcoming task by encouraging himself; or he may bring forth repressed traumatic experiences so as to make himself aware of the traumas and to master the affects connected with them; or he may tell himself more clearly than in waking life how he feels about someone who is close to him; and so forth. In a sense a person, by producing a dream, sends a message to himself."

The present concept of sleep will make full use of this description in the portion devoted to dream analysis. The only needed modification of this description concerns a strengthening of the last sentence. It will be assumed that a person literally sends several related messages to himself in his dreams, messages that underpin his subsequent waking activity, acting much like post-hypnotic suggestions in this respect. The association between REM dreaming and hypnosis is assumed to be not merely analogous. It is conjectured that a person enters a hypnotic trance by reverting to the same physiological state of receptivity found in REM dreaming. That is, while hypnotized, a person is in a state derived from the REM state, with the difference now of course being that the experienced suggestions come from someone else.

One immediately runs into problems when attempting to cast the foregoing description into general mammalian terms, particularly because of the word "thought." No attempt will be made here to construct an anthropomorphic bridge to link the disparate concepts used in describing human and lower-animal learning. It is necessary, however, to say something about lower-animal learning experiments, if nothing else to indicate what types of sleep-related experiments have a bearing on this concept of sleep.

The model of a learned behavior used here is that of a skilled performance. Although a skilled performance may appear automatic and have the character of being rapid, accurate, and smooth, it is inaccurate to think of such a behavior as a single perfected action. Rather, a skilled action is a series of very rapid trial responses and feedback-based corrections. Involved is a process of cue differentiation and continual correction for errors. In a skilled behavior, each separate action occurs at just the right time and with a force that is in correct proportion to the force of the other movements. Expertise is distinguished by the fact that the organism has integrated relatively large sequences of behavior, so as to tie a whole series of acts together.

This brief summary statement is meant to indicate that it is a form of self-deception to characterize the learning of a skill as the "consolidation of a memory trace." A close examination of a skilled performance shows that a behavior is rarely if ever performed exactly the same way twice. A learned behavior is, therefore, not a piece of machinery made by rigidly linking component behaviors in a sequence. The components are linked but rather as an integrated network of possible responses. This is what is placed at the mammal's disposal. For this reason, it is perhaps better to speak of a skill as a behavioral integration.

To see what the term integrated network means, let us consider the example of a fox chasing a mouse. The skills each applies in this situation are based on past experience, so neither can be altogether sure about what the other will do. The fox, for instance, has trained to catch this particular mouse by chasing other mice, mice that tried somewhat different evasive tactics each time. This mouse too will present surprises. The point here is that the fox and mouse both need a flexible mode of response to be successful, because neither can predict moment-to-moment exactly how the other will respond under present circumstances. Each needs a repertoire of expectancies and associated trial responses and feedback-based corrective maneuvers to have the best chance possible of meeting their respective goals.

It is usual to speak of long-term and short-term memory processes, and what is being discussed here is evidently something somewhat different, so perhaps another example is in order. Those who play tennis and who do not belong to a tennis club or live where tennis can be played year-round find themselves "rusty" in the spring. They play better than they did when they first started playing the game, but are somewhat uncoordinated and slow to get a jump on the ball. A week or two of playing, however, brings the old skills back.

It is evident that the components of a tennis player's former skills lie in long-term memory but are initially unavailable to the person as he plays. In other words, the act of playing is not sufficient to evoke all of these behaviors directly from long-term storage. What is required is that the memories be dredged up and integrated together in what may be called the person's current memory. Playing each day helps reestablish the old skills, but the position taken here is that more than the daily practice is involved. Sleep also participates as an aid in reintegration and recall.

The life of a mammal in the wild is considerably more complicated than that of the typical laboratory animal. It is constantly being called upon to adapt its old skills to new requirements as quickly as possible. This is true of humans also, particularly in their social interactions. Here the old skills are generally spoken of habits and beliefs that have their ultimate origin in childhood.

THE STAGES OF NORMAL HUMAN SLEEP

The following description is taken from "The Psychology of Sleep," by David Foulkes, 1966, for the most part.

When a person closes his eyes and attempts to sleep, his EEG grows in amplitude and becomes more regular. Soon a 10 cps waveform dominates the record. A person at this point has not lost voluntary control over his actions. Rapid eye movements (REMs) are present and are probably related to some voluntary imagining or semivoluntary daydreaming under closed lids. Waves 8-10 cps in frequency are called alpha waves. This stage is called the alpha-REM stage of sleep onset.

As sleep processes begin to take hold, the alpha rhythm becomes fragmented and the voluntary REMs are replaced by a slow involuntary rolling of the eyes back and forth in their sockets. Although a subject awakened from this state would likely say that he was "awake but drowsy" or "drifting off to sleep," the probability is that at this point he would be functionally blind. Were his eyes taped open and this point reached, he would probably be unable, when awakened, to report what objects the experimenter had waved before his slowly rolling eyes.

In time, the alpha rhythm disappears completely and is replaced by a low voltage, mixed frequency pattern with the preponderance of activity in the 2-7 cps range. Slow eye movements may persist or the eyes may become quiet. This stage is taken as the point at which actual sleep begins. Accordingly, this EEG pattern is labeled sleep stage 1.

As ˇsleep continues, so does the low voltage pattern. In time, however, this becomes punctuated occasionally with one or the other of two new waveforms. One of these is a short wave of moderate amplitude with frequency 12-14 cps, called a sleep spindle. The other is a sharp, high voltage slow wave with a positive tail, called a K-complex. The appearance of either of these shows that stage 2 has begun.

With the deepening of sleep, high voltage 1-3 cps waves, called delta waves, begin to appear. When these occupy 20-50% of the record, the sleep is said to be stage 3. When these increase to more than 50%, the sleep is taken to be the deepest sleep of all, stage 4.

A person's initial sleep progresses fairly rapidly to stage 4. He is often in this stage within twenty minutes of falling asleep. After about thirty minutes of stage 4, a lightening of sleep takes place. This lightening ends with the appearance of an EEG very similar to that of the initial stage of sleep, stage 1. This is an EEG, however, that bears similarities to that of wakefulness, too. The stage of sleep is the REM state, as is confirmed by the eventual appearance of REMs.

A short 10-minute REM period brings the first sleep cycle to an end and gives way to a second non-REM (NREM) sequence that is much like that of the first cycle, in that both contain a good deal of stages 3 and 4. After this second NREM period, REM dreams become progressively longer and stage 2 becomes the dominant NREM stage that is seen. A night of human sleep may contain 5-6 sleep cycles.

SLEEP STAGE ACTIVITY ASSIGNMENTS

Recall that each of our activities during the day start a process of reintegration wherein we strive to learn from our experiences. The position taken here is that this process is brought to completion in sleep. The following admittedly vague activity assignments attempt to indicate how that happens.

Stage 4: In stage 4 sleep during the first cycle, the process of reintegration involving all of the activities of the previous waking interval is brought to completion to the extent possible without further experiences. The activity contributes to the formation of what will be called the mammal's "basic adaptation."

Stage 3: Stage 3 is a transitional stage wherein work on the basic adaptation continues. Stages 3 and 4 are lumped together by some researchers who point to either as delta sleep.

Stage 2: Stage 2 is less concerned with behavioral analysis and reintegration and more concerned with making final preparations for REM dreaming.

REM sleep: Roffwarg, Muzio, and Dement (1966) have interpreted the REM state as involving a simulation of experience in a literal sense. They postulate that it involves a presentation of sensory material and suggest that this "internal sensory input" is presented in such a way that "higher centers [of the brain] interpret and react to it as if it were a set of true percepts impinging on the central nervous system from without." These interpretations are accepted here without modification.

When work at arriving at the basic adaptation is completed in stage 4 during the first sleep cycle, a process is initiated aimed at experiencing the adaptation in the REM state. In contradiction with virtually every theory of dreaming other than CMT, the aim in experiencing the basic adaptation is assumed to be reality testing. That is, the adaptation is experienced so that it may be tested in the real world of the mammal's memory. The process of reality testing also serves to establish the new behavioral integrations in the mammal's current memory. As the adaptation is experienced, related memories that have not been included are evoked. These memories point up inadequacies in the adaptation and eventually accumulate to the point that the REM period is brought to an end.

The second sleep cycle also generally contains a good deal of delta sleep, which is interpreted as meaning that the "criticisms" of the first REM state must be generally severe, calling for fundamental changes. That delta sleep tends to disappear from the record after the second cycle is taken to mean that the basic adaptation has been essentially completed and that sleep henceforth concerns itself with fine-tuning the adaptation.

SLEEP AS PROBLEM SOLVING

To remove some of the vagueness of the sleep stage activity assignments, an effort will be made to draw comparisons between sleep and a common daytime activity, that of problem solving, since it is obvious that that is what sleep is assumed here to be. This comparison is within the realm of CMT, which stresses that our dreams are attempts to solve problems and are perhaps more rational than our waking thoughts.

We humans are able to generate a variety of inner experiences. Examples of these are mental images, an inner voice, emotions, feelings, neurotic symptoms, and moods. In other words, REM dreaming is only a more engrossing form of a general capability that extends to wakefulness too. Just as hypnosis and REM state receptivity to experience are related, so too are the dream display and the ability to generate inner conscious events while awake.

As preparation for the following discussion, the reader is asked to recall the last time he or she worked to solve a difficult math problem or any other difficult problem that was solved in a single sitting. Initially we don't have a clue as to how to proceed. Our minds are blank at this time. There are no relevant inner images, no insightful thoughts from our inner voice. About the only inner event present is an uncomfortable feeling traceable to an anxiety born of doubt about whether we will be able to find a solution.

Although we don't seem to be working very hard on solving the problem during our blank interval, we evidently are, because eventually out of the blue an idea will pop up that reveals itself to be an organized plan of attack. Now images and thoughts rush pell-mell to mind, as we seek to work out the details of this plan of attack to reach the answer in the back of the textbook. As we work, however, we find that the plan of attack starts running into snags. Various aspects of the plan don't in actuality hang together as well as we supposed. Eventually we give up on the plan, and our minds go blank until a new idea pops up. Generally speaking, this alternation between unconscious and experienced thought is characterized by long unconscious periods and short conscious intervals at first, with the conscious intervals becoming longer as we make continued progress in working out the details of our solution. This alternation between unconscious and experienced thought is assumed here to be the way we humans solve problems whether awake or asleep.

EXPERIMENTAL TESTS OF THE CMT-BASED MODEL OF SLEEP

Dement end Kleitman (1957) offer three somewhat different depictions of representative nights of normal adult human sleep that cannot be reproduced here. It may seem trivial to say that the concept of sleep outlined above is consistent with these diagrams; however, that is not quite the case. The authors do not indicate whether these were taken from the sleep of the same subject, but the fact is that they could have been. Although our sleep cycles generally remain 90 minutes long, there is considerable variation in the distribution of sleep stages within a given cycle. No two nights of sleep are ever exactly the same. The theoretical edifice that has been constructed would have collapsed immediately if they were, because it would have been exceedingly difficult to explain how a cognitive analytical process could be so regular. The uniqueness of each night of sleep does not, of course, prove anything, but it does allow the discussion to continue.

Character of First REM Period

The large amount of stage 4 sleep generally found in the second cycle can only be interpreted as meaning that the first REM period has appeared while a person's basic adaptation is in a relatively immature stage of development, which means that one should expect to find evidence that the critical reaction operating during the first REM period is particularly sharp. One expectation is, therefore, that this REM period should generally be brought to an end much more quickly than subsequent dreams. Table 1, from Dement and Kleitman, is consistent with this expectation.

TABLE 1

Mean Duration of Successive REM Periods

1st 9 Min. 2nd 19 Min. 3rd 24ˇ Min. 4th 28 Min. 5th 34 Min.

In discussing the characteristics of the various REM episodes, Dement and Kleitman make mention of another possible indication of a particularly sharp critical reaction. In a discussion of the persistence of the stage 1 EEG during a REM period, they mention that "rare exceptions to this occurred when the EEG changed briefly to stage 2 in the middle of an eye movement period." They go on to state that "this 'slipping' down to stage 2, when seen, usually happened during the first eye movement period and almost never occurred later in the night." These movements to stage 2 can be interpreted as "quick-fix" attempts to keep the REM dream going despite an ongoing sharp critical reaction.

Shown in Dement end Kleitman's middle sleep diagram is an apparent instance of a REM period attempt that was aborted in stage 2. Implicit in the assumption that stage 2 is primarily concerned with making final preparations for REM dreaming is the contention that this stage is a physiological "place" in which critical evocations to a REM presentation can best be anticipated. Thus, occurrences such as this, occurrences which, incidentally, take place about 20% of the time, can be interpreted as the result of stage 2 judgements regarding the inadequacy of the NREM thought.

If the first REM presentation is actually inhibited by a sharp critical reaction, one would think that the character of this first REM dream should show signs of an inhibited simulation of experience.

This first REM dream is in fact the least vivid of all our dreams of the night. The dreamer's sense of participation is so limited here that there is a strong tendency for him to say that he was merely thinking. About 75% of our dreams from the 2nd through the 5th are in color. As for the first REM periods, 75% of these are in black and white (Herman et al., 1969).

REM Dreaming as a Focal Activity

The concept of sleep offered here actually makes a sweeping statement with regard to the way the progression of sleep stages is to be interpreted, in that the REM state is depicted as ever the focus of sleep's activity, with the NREM portions contributing merely preparatory effort. Implicit in this is the view that every upward swing in the EEG must be interpreted as a movement toward dreaming, even when the effort is abandoned before stage 2 is reached. By the same token, every downward movement toward stage 4 must be seen as a movement away from dreaming and toward a more profound and isolated level of thought.

Some evidence bearing on these conclusions can possibly be had by considering the occurrence of body movements during sleep. Unfortunately, much of the evidence in this regard comes from Dement and Kleitman's diagrams, which were not meant to be interpreted in detail. Shown here is a strong tendency for body movements to occur near the onset and termination of REM periods. Body movements can also be seen within some REM periods as well.

Dement and Wolpert (1958) conducted a study of the body movements that take place during REM dreams. They found that these were correlated with the blank intervals between separate dream scenes. Thus the relationship between body movements and the start and stoppage of a dream display appears to be general.

If general relationship is assumed, then the foregoing interpretations imply that upward swings in the EEG, being swings toward REM dreaming, should often be accompanied by body movements, while downward swings should not. Dement and Kleitman's figures show such a tendency in all three drawings, Shown here also, however, are some body movements coincident with downward shifts and others correlated with no shift in NREM EEG stage.

In pursuing this matter further, it would be of interest to know whether the body movements at the onset of REM periods are generally of a similar type. If such a consistent similarity can be found, then this concept of sleep would predict that most upward swings in the EEG would be accompanied by body movements of this kind.

A second consideration has to do with the fact that lighter and deeper moments exist in each NREM stage. It is possible that at least some of the body movements that take place during a particular NREM stage could be correlated with a temporary lightening of stage that is not long enough to be counted as a stage change.

Auditory Arousal Thresholds

The various NREM stages have been spoken of as physiological "places" with respect to the REM state. Specifically, stage 4 has been interpreted as being most distant from REM dreaming, while stage 2 has been portrayed as being most close. As it happens, there is a way to test these "distance" assignments.

Implicit in everything said so far is a belief in the physiological similarity between REM dreaming and the waking state. If this similarity is in fact real, then a measurement of the proximity of each sleep stage to the waking state should correspond to the relative physiological distance of each NREM stage from REM dreaming. In other words, if stage 2 is relatively close to REM dreaming, then these two should be found to be approximately equidistant from the waking state, whereas stages 3 and 4 should be found farther away as measured by the auditory arousal thresholds of the separate sleep stages. And one way to do this would be to introduce a tone during sleep and count the number of times this intrusion led to an awakening, with fewer awakenings presumably meaning a more distant stage.

Rechtschaffen, Hauri, and Zeitlin (1966) performed such an experiment. They found that subjects awoke 55.7% of the time from REM periods, 62.0% of the time from stage 2, but only 19.4% of the time from delta (stages 3 and 4 combined) sleep. The difference between 55.7% and 62.0% was found not to be significant, whereas delta sleep was found to be significantly deeper than these other two stages.

Another aspect of the data Rechtschaffen et al. present is perhaps pertinent. It has been said that sleep represents a turning away from the waking state for the purpose of making one's self "ready" behaviorally for the following day. It has also been indicated that this readiness perhaps only begins to take shape with the first two cycles of sleep and that afterwards REM refinements to the basic adaptation are made. Assuming that a person's sense of readiness participates in his readiness for arousal in morning, one would suspect that a lack of readiness would contribute to a reluctance to being awakened. Thus, during the first two cycles, one should find that arousal thresholds are greater for each stage than they are for the same stage later in the night.

The first two cycles of sleep usually occupy 2.5 to 3 hours. Rechtschaffen et al. divided their subjects' 7-hour sleep into two 3-1/2-hour intervals and considered the mean arousal threshold of each stage during each portion.

They found that late REM trials produced significantly more frequent awakenings (63.1%) than did early REM trials (45.3%). In addition, they reported that 42.7% of early stage 2 trials produced awakenings as compared with 69.9% of the late stage 2 trials. Early delta trials, however, produced approximately the same frequency of awakenings (21.7%) as late delta trials (22.5%), although the authors add that very little data contributed to this comparison.

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