Brain activity during sleep and dreams

[~¤LilacSky¤~]

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?

[~¤LilacSky¤~]

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.

[~¤LilacSky¤~]

Lucid dreaming and brain activity-

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.

[nani]

very interesting, thank you for bringing it here, Ronni.

"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."

Thats truly interesting.

"There are limits to being conscious while you're unconscious."

I dont think thats true! You?

"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?" "

This is funny and interesting on top. I never thought about from what moment on we are conscious about if we have a dream-I or not, respectively become more than only the observer.
I didnt know that childrens only are observers in their dreams.
Something to think about.
Thank you Ronni.
best regards
nani

[~¤LilacSky¤~]

hmm, im not sure Nani if I beleive that, I don't think so though, thats interesting about kids..I always thought their dreams were more vivid and more in depth than adults since they have not been fully programed by society yet or molded in what they should be..
I think honestly that our world can strip away our true selves and inner knowledge, since power and money seem to control the world, the physical is blinded by it and as a child we don't see these things