Sleep and Consciousness
This is an invited address on consciousness in sleep given at the Smithsonian Institute, Washington, D.C., for a lecture series entitled "The Brain and Consciousness: Frontier of the 21st Century", May 19, 1994.
Freud helped us focus on consciousness with the idea that there's an unconscious and never the twain shall meet. They're separated because, according to Freud, we're driven by unconsciousness impulses. To the point where it can feel like, "who the heck is driving this boat called 'me'." I've been interested in this question for most of my life. I'm a first generation baby boomer, born 1946. I've done all that baby boomers were supposed to do including living in New Mexico in the 6O's. After doing the prerequisite baby boom agenda of the 7O's, I shaved my legs after finishing my master's thesis on a feminist topic and went on to get my doctorate. In looking for a topic for my dissertation the question of consciousness came up as I watched the death of an elderly friend.
Thus my research, writing, and a lot of my thinking has been involved with dreams and sleep, and in particular the experience of consciousness during sleep or lucid dreaming. During this experience you're sound asleep, which we popularly think of as unconscious. You're whacked out and lying there in bed. If that isn't unconscious, I don't know what is. Yet at the same time some say they know they're dreaming. This seems a paradox. How can you know you're unconscious when you're unconscious? If you're unconscious, you can't be conscious. You get into this sort of wafflely feeling just thinking about it, so ingrained in our society is the idea of consciousness and unconsciousness being mutually exclusive. If you've had the experience of knowing you are dreaming while you're dreaming, then you know what it is like. Typically it's fun and you enjoy it. If you've never had it you may scratch your head and feel confused. In any case for 20 years I've pursued these questions. I'm 48 years old, and I'm still wondering who's driving this boat, while awake and while asleep? I've a little better idea which I will share with you tonight.
I'm going to try to walk that thin line between an intellectually sophisticated member of the audience and the person who's kind of interested but not really informed about contemporary psychological thinking. I shall try as much as possible to broach that gap. I'm going to start by talking in general about some of the biology of sleep and dreams and then move into the notion of consciousness in sleep and the various forms that consciousness can take in sleep as it develops.
Brain/Body Activity During Sleep and Dreams
There are three majors measures of sleep that are used in the sleep laboratory; brain waves, eye movements and muscle tone. In Figure 1 waking is compared to the two basic categories of sleep: NREM and REM sleep. Some of the major markers of these differences which are apparent with this kind of very brief look at a polygraph record is the eye movement activity, which in rapid eye movement (REM) sleep is quite intense. Certainly relative to NREM sleep, and even much more variable and dense than during waking. Muscle tone is also quite interesting. Waking muscle tone is high relative to NREM muscle tone which is moderate, but what's interesting about REM is that there is virtually no muscle tone. For all practical purposes you're paralyzed!
When you go to bed at night, you sort of snuggle into your favorite sleeping position. You may be a side person or a back person or sleeping on your stomach may be the only way for you to settle in. Once you get yourself settled in Figure 2 shows the sequence of events that occur in sleep. You start in light sleep at point "A" while point "B" is deepest sleep. There are several features I'd like to point out on this figure. First you cycle between light and deep sleep throughout the night, about every hour and a half. This hour and a half circadian rhythm we actually experience throughout the twenty four hour day and thus it simply continues into sleep. It's particularly noteworthy in sleep because of the movement into what is called rapid eye movement sleep (REM). It is associated with dreams but this association is not absolute. You can see at "C" that there is mental activity that we might call dreams that occur in non-rapid eye movement sleep (NREM). So although there are some dreams, for the most part, they are clustered in the REM episodes.
Furthermore, the dreams of REM sleep are phenomenologically quite distinct from those in NREM sleep. There's been an argument in the dream research literature about whether or not REM sleep is the biological marker for dreams. That's what it was touted as when first discovered in the early 1950's. Then with subsequent research sleep and dream scientists got disillusioned with that simplistic isomorphism and concluded that dreams go on all night long to one degree or another, they simply cluster in REM.
As is often the case in science, we have gone almost full cycle and realize that there are real phenomenological markers of mental activity during REM that are quite distinct from mentation during NREM sleep. One difference is bizarreness. In a recent article by Harry Hunt in the journal Dreaming, he was able to show that attempts to equate the bizarreness of REM sleep mentation to the bizarreness of NREM sleep mentation doesn't work. In other words, REMing dreams are distinct from NREMing dreams.
Lets return to Figure 2. You can see at "D" that REM episodes get longer as you go through the sleep cycle. Therefore most of your dreaming happens late in the sleeping cycle. Those dreams which last from 30 to 40 minutes have the elaborate story lines and complex shifts and transitions which we call bizarreness. Your mother's got a purple face. Tin cans are growing out of people's heads. That's the kind of stuff you are experiencing during these early morning hours. That's the kind of stuff that "real" dreams are made of!
There you are paralyzed from the neck down, your eye movements are jerky and rapid, your heart rate fluctuates, your breadth rate changes. Sometimes when you wake up from an especially intense REM episode you may be panting, your heart's pounding and you're sweating. And you mutter, "Thank God, that was only a dream!" If that happens you have come out of rapid eye movement sleep. So for instance, if you're an ulcer sufferer there are twenty times the amount of stomach acid secretions during REM than during NREM. If your child has asthma and they wake up with an asthma attack, they're likely waking from REM sleep. If you have angina, these heart problems are going to occur most likely out of REM sleep. In other words, REM doesn't seem to be really good for your health. It stresses the body. It pushes all these different systems more so than while awake. Not while your jogging ten miles, obviously, but this whole system is going to be really revved up in the main more so than while awake. In addition, while all these systems are on over-drive, the brain is increasing its activity. What is going on?
Functions of REM and NREM
During rapid eye movement sleep is the time when new information is processed and stored into our memory banks. Our personal experience of this very important brain function is dreaming. A world is created. When you're in a dream it feels real. Even if you know it's a dream at the time it feels real. If you jump up in a dream and you fall down you feel the thud. Although when you wake up, you realize "oh well, that was a dream" and then tend to minimize and dismiss it, but the feelings of it's reality are there during the dream.
So how come whoever put this system together, God, nature, whatever, made this time when we are hallucinating so much that we think it's real. We're having all these emotions. All this bizarre stuff is going on. Our body is responding like mad while we are paralyzed from the neck down. Furthermore if we weren't paralyzed there is good evidence that we'd get up and act out the dream. Recently in Toronto a man got up from bed in the middle of the night, got into his car, drove across town, and killed him mother-in-law. A colleague of mine testified at the court case. He took him to his sleep laboratory in Boston and monitored the Toronto man's sleep He told me there is no doubt, it is easy to identify as can be seen in Figure 1. You can see that muscle tone has flattened out in REM but in his REM the muscle tone did not flatten out. He had muscle tone. Enough to murder.
The point is, if we didn't have that paralysis we'd act out our dreams. Can you image acting out your dreams? Maybe your dreams would be okay but some of my dreams, I don't know! So how come this thing called REM is there? There is all this activity on a biological level. From the intra-psychic, heavily psychodynamic level, all my inner self, unconscious motives and drives or all my "junk" is in there. That combination sounds interesting all by itself. We have some idea of how these things develop and Figure 3 gives you some indication of it. If you look at the percent of waking as we go through the life span from infancy and birth through childhood and adolescence to adulthood and old age you see it increases. Along the horizontal axis are the daily sleep and waking requirements. You can see that in infancy there are huge amounts of REM sleep relevant to the rest of your life. We certainly know newborn infants sleep a lot, that the older you get you sleep less and less and thus you have less and less REM sleep.
These data give us some hint as to the functions of REM and NREM sleep. Very briefly these are: information processing for REM whereas the function of NREM is somatic, vegetative maintenance. In other words NREM restores the body. For instance, growth hormones peak during delta sleep. Delta sleep is the deepest NREM sleep. So children not only have to get enough sleep, they've got to get enough delta sleep. Delta sleep tends to occur early in the sleep cycle. There's a disorder called social dwarfism where there is a failure to grow, children with it are unusually small. It was called "social" cause no biological mechanism could be discovered but they found that among failure to thrive children there was a high incidence of family dysfunction. There was a lot of stress and tension in the family. It may be that the children's sleep cycles are being disrupted enough so that there was not enough growth hormone being released during delta.
Another piece of evidence that supports the vegetative restorative function of NREM sleep is when there is high pre-sleep metabolic rates they are associated with higher levels of delta sleep. So if you're working on getting your metabolism up you are going to need more delta sleep. Also higher brain functions appear to be somewhat reduced during delta sleep. Slightly less brain oxygen consumption and as noted psychological events related to it are sparse.
REM sleep plays a role in the reorganization, restoration of brain processes that mediate the flow, structure and storage of information. This includes things like problem-solving, memory consolidation, information processing, and creativity. About 50% of the sleep cycle of the newborn is REM or quasi-REM kinds of sleep. Newborns sleep 16 to 20 hours a day. That is eight hours of REM! A reasonable question is, "What are they dreaming about, after all they were just born?" Although one could get metaphysical and talk about past lives it's not really necessary.
It turns out that when an infant is born although they have all their brain neurons, the communicating aspect of the neuron, the synapse which connects neuronal cells, have just begun to grow about a month before birth. Without the ability to communicate with each other the neurons are virtually useless. There are enough synaptic connections at birth for some basic survival behaviors. For instance, a newborn will recognize their mother's voice at birth and can see with perfect visual acuity for about 8 inches, the distance to mothers face as nursing but not beyond, which would be confusing and disruptive to the bonding process with the mother which must occur for the newborn to ensure its survival. Still there are a lot of neuronal connections to be made. After all getting that thumb in the mouth without poking ones eye is a fairly major task particularity when mom's not around. Learning to coordinate visual input, thumb, with motor output, moving it to mouth, takes synaptic connections. This growth of the synapses probably occurs during REM sleep. Because the newborn has so much to piece together in terms of simply getting all the potential motor activities working properly, among many other tasks, it is no wonder that they need huge amounts of synaptic growth time or REM. Along the same lines a premature infant will show as high as 75% rapid eye movement sleep.
Other evidence pointing to this cognitive function for REM is with the right hemisphere. Although the right-left hemisphere dichotomy has been over simplified, there is relatively more activity in the left than in the right hemisphere of the brain during the day. What happens at night is not that the right hemisphere takes over rather it increases activity to the level of the left hemisphere. Therefore the kind of information that is best processed in the right hemisphere in conjunction with the left hemisphere is going to happen in the main during REM.
On a psychological level REM may serve some compensatory process function as hypothesized by Freud. Personally important experiences may be repressed during the day and thus you'll see a reciprocal emphasis in dreams at night. More often than not, however, you'll see a continuity between presleep experiences and dream experiences of the REM or NREM sort. What you've been thinking about before you go to bed at night, you'll see in the dream of that night. This is especially evident in our children. When my son was about 8-years-old we were impressed with the advertisements for a movie about cute little "Gremlins". Naively we went to the theater but during their first transformation with water into sharp toothed small but lethal monsters we both high tailed it out to the lobby. Not surprisingly that night about 2 a.m. I felt a small body crawl into bed with me. The "gremlins" from the show had awoken him from a nightmare!
But to simply reduce dreams to meaningless rough reproductions of waking events is also to reduce their importance. Most dreams occurr during the time of the sleep cycle when we process new information into our memory banks, REM sleep. Therefore dreams are always autobiographical and unique to each individual.
Why is Dream Forgetting Common?
If these experiences of the night are so biologically and psychologically important, how come we typically forget our dreams upon awaking? The norm in the dominant European culture of North America is dream forgetting. The average adult sleeps about eight hours a night and of that about two hours is REM or dreaming sleep. That's usually four dreams every night. Very few people remember even one dream a night no less four a night! The average is four a month, which would be about one a week. The norm is we forget dreams. There are various reasons but the three major hypotheses related to our failure to recall dreams which have been investigated by dream scientists are: repression, salience and interference.
The concept of dream forgetting being due to the repression of unpleasant emotions/experiences is classically Freudian. This is the idea that the dark side of my inner self, which I'm not ready to deal with, may emerge in dreams thus I forget the dream. Some Freudian analysts might argue that if you remember a dream, you're ready to deal with that material. Although there is some evidence for the repression hypothesis it is probably not the major reason we forget dreams.
The salience hypotheses states that some dreams are so personally impactful that you couldn't forget them. You wake up in the morning and your life has been changed or you hope like heck you life hasn't been changed. When my children were about nine and four I had a dream that they were crossing the street at a crosswalk with a friend of theirs. All three got hit by a car and were killed. I recall waking up and being absolutely terrified. I jumped out of bed and went to check on them. They were both sound asleep and in good health. None-the-less the fear would not leave me so I did something that I rarely do, I knelt by my bed with tears running down my face and prayed to God that this dream never come true. It still sends a shiver down my spine to even think about it! That is a dream I can not forget and in fact I still get anxious any time I know they will be in a cross walk.
Despite experiences of this sort of impact, probably the major reason we forget our dreams, according to scientific research, is something quite simple. It is interference. It's the same reason why if I said to you "I want you to tell me about your breakfast this morning". If you didn't remember you'd start to sort of extrapolate, "I normally have yogurt and fruit, so I must have had yogurt and fruit." You might remember some of it but I doubt many of you would include details like the number of glasses on the counter or other ordinary details. If you got a new table cloth, you might mention it. But if it's something that happens every day it's probably not high on your need to recall list. Other things interfere with that recall like the families hurry to get to work and school because mom overslept. When we wake up from a dream most people immediately think, "Got to get up. Got to get ready for work . Got to get the kids dressed. Got to get breakfast." It's forward thinking and interferes with the recall of what was just happening to us in our dream. Occasionally we will simply lay there and drift but still the simplest things can interfere, like moving or opening your eyes. Or we will wake up and think, "I was dreaming. I don't have a clue what it was. But I was dreaming." It's sort of like the tip of the tongue phenomena or may feel like peanut butter on your tongue. When my son was three-years old he couldn't image being awake while I slept so he would "helpfully" come into my bedroom, lift my eyelid and cheerfully announce to me, "Wake up time mommy!" I went through a rather long period of dream forgetting due to his well intended interference.
There are some other factors I'd like to briefly point to which may contribute to dream recall. When I moved to Canada I started working with the Central Alberta Cree and quickly found out that their dream recall is quite high. Not only is this my personal observation but there is research on the Cree done before I got there as well as my own substantiating this observation. Because of this work it has occurred to me that perhaps part of the large dream forgetting characteristic of Euro-North American's is our cultural taboos around attending to this sort of material. We're not supposed to pay attention to our inner lives. We're not supposed to take them seriously. In fact one theory of dreaming in REM sleep is that it's garbage. It's the way the brain makes sense of presumably random neuronal firing from the brainstem. Thus according to this perspective recalling dreams is recalling garbage and couldn't possibly be healthy. That theory has been generally debunked. I am not saying that every single thing you dream every night is equally important but I do think there's a moderate position.
Metaphoric Magic in Dreams
Dreams speak to us albeit it is in a different language. The language is metaphor. While awake we might use the metaphor rose to refer to rosy cheeks while in dreams that rose may be thorny and may refer to Rosie, someone you work with who has a thorny personality.
Therefore the language of our "un"consciousness in sleep can be difficult to understand. Metaphors used in dreams are often idiosyncratic and personal but it is a language you can learn that is somewhat culturally specific. If you were raised in a culture where from day one you were told that if you dream about a white Volkswagens it meant you would get a job. So that if you got a job you'd be sure to dream about a white Volkswagen. Unfortunately most of us are not taught these keys to our inner life thus we are left to our own devices in interpreting our dream metaphors.
Lucid Dreaming: The Maximum Self-reflectiveness?
Most of the way we experience consciousness in sleep is in the form of dreams. And most of the dreams that we recall come from REM sleep. This time of sleep has been called paradoxical because as noted we're paralyzed yet our physiology is so juiced. We're in this alternative reality in every way, shape and form. But there are many forms of dreams which societies have identified over the years. As my topic is consciousness in sleep I will now turn to one of these intensified REM forms called lucid dreams.
This hyper-REM phenomenon is significantly more of whatever REM is. Lucid dreaming is when you know you're dreaming while you're dreaming. You're sound asleep and dreaming believing that the dream is reality when for a variety of reasons you recognize it is a dream and that you are in fact asleep. Typically people react initially with a sense of wonder and fun. They quickly realize that they can do in a dream all these things they could not do while awake. However this initial excitement also often wakes them up. Because you get so excited you can't stay asleep. There are limits to being conscious while you're unconscious.
There are various ways to conceptualize lucid dreaming. One is in terms of the relative self-reflectiveness that the attainment of such a state of consciousness might imply. Canadians Alan Moffitt and colleagues developed a scale measuring self-reflectiveness based on the therapeutic work of Ernest Rossi. In it they consider degrees of self-reflectiveness in dreams. The classic position has been that in most dreams we are fairly unself-reflective or critical of our dream surroundings/events/characters. For instance, I recall one of my students telling me that he knows he's dreaming a lot. I asked, "how do you figure that out?" He replied, "Well, I know if I'm in an airport in a dream and my car is there and it's blue, and I know my car's not blue. I know my car's purple. Ergo, it must be a dream. " I recall thinking to myself, if that was me in the dream and there was a purple car instead of a blue one, I'd think "oh well, something must have changed and I now have a purple car". I'd just drift along accepting whatever came my way. In contrast this student is very critical in his attitude in waking and that translates into dreaming thus he is often able to identify that he is dreaming. That degree of reflectiveness, or critical attitude, is actually quite rare.
At the lowest level this self-reflectiveness scale begins with "The dreamer is not in the dream". Researchers have found that this is one of the first experiences of dreaming that children have. It takes quite a while until they begin to move to the next stage of thinking abilities when they can begin to construct the self enough to have a self in the dream. One day when I was telling my seven year old boy my dream he looked at me with an irritated expression. I asked him, "What's wrong?" He said, "How come you get to be in your dreams, and I don't?" I remember thinking that was a fairly sophisticated observation. Without explaining that he has cognitive limitations, I assured him that eventually he would be there and of course he is now fully in his dreams. Although occasionally young children are in their dreams as active characters more often than not they are watching, or they have a sense of it happening out there somewhere. A self in ones dream is a developmental benchmark.
The midway point on the scale is when the dreamer becomes completely involved in the dream. This is where many of us remain, completely absorbed in the dream so much so that if it is a nightmare we are so relieved when we finally awaken. Eventually we have some experience of some kind of reflective activity like thinking about an idea. So in the dream we might mutter to our dream selves, "This isn't quite right." Particularly as we utilize the highest form of logical thought called, formal operations. The reality is that only about half the time do we actually end up doing thinking at this higher level even when awake!
At one of the higher levels on this scale the dreamer has multiple levels of awareness simultaneously participating and observing. This would be a dream where you're watching yourself doing something and you're in it and out of it at the same time. But it still feels real. Another example would be a false awakening dream. In it you dream that you wake up, and then you really wake up and realize that you dreamt you woke up. Did you ever do that two or three times in a row? You know you dream you wake up, and then you dream you wake.. and then, and then, and then....after all "waking up" can get scary? I recall doing it once four times in a row, and I was getting pretty scared thinking, "what's real and what's not?" Another example of the slipperiness of reality that these dream experiences can subject us to is the dream where you were so sure it was real that you comment on it as though it were real to a friend. They look at you like you're crazy and only then do you realize in embarrassment that "I dreamt it!"
These things get very slippery. What's dreaming and what's not dreaming? What's real and what's not real? It can get quite confusing. A colleague of mine has a great slide that he uses in his presentations of a huge toilet with a little person standing there looking at it! It illustrates the dream where you are telling yourself, "it's OK, you're awake you can pee!" when another part of you replies, "No. You're asleep. Don't go!" Did you ever lose that argument?
At the highest level of Moffitt and colleagues scale the dreamer consciously reflects on the fact that he or she is dreaming. This is the lucid dream. It is the experience of, "Hey, wait a minute, this is a dream. That's why there's a tin can growing out of that guy's head or that's why I can fly like superman!" Although for these dream researchers that is the highest level of self-reflectiveness, I'm going to argue it's the basement of the potential of consciousness in sleep. And in fact, the potential of consciousness in the twenty-four hour cycle.
Lucid Dreaming Proof