Brain activation in sleep

Activation-synthesis ascribes dreaming to brain activation in sleep. The principle engine of this activation is the reticular formation of the brain stem, just as it is in waking, but the chemical mode of activation is distinctly different. It is for that reason and that reason alone that dreaming and waking consciousness are so different. In waking, the noradrenergic... 

Instigation Repressed unconscious Brain activation in sleep... 

But the real payoff of exotic dreaming is its naturalism. By virtue of being a product of apparently life-sustaining brain activation in sleep, it is not only necessary but free of charge, free of assault trauma, and free of long-term health risks. 

All human beings who have been studied in sleep labs have brain activation in sleep. Periods of brain activation during sleep are associated with rapid eye movements in the sleeper. These rapid eye movements give the brain-activated phase of sleep its name REM or rapid eye movement sleep. When awakened at the time of intense clusters of rapid eye movements, 95 per cent of sleepers studied in labs report dreaming. From this evidence, it is generally assumed that everyone does, in fact, dream in sleep any impression to the contrary is related to the difficulty recalling dreams. 

It was the combination of EEG and EOG that enabled Eugene Aserinsky and Nathaniel Kleitman to make their 1953 discovery of brain activation in sleep. They called the brain activation phase of sleep REM (for rapid eye movements) because of the association of the activation of the eye movements (oculomotor activation) with activation of the brain. They asserted that dreaming might be another associated event. It was the EMG (together with the EEG and EOG) that allowed Michel Jouvet and Francois Michel to show that muscle tone supporting posture - and hence postural movement - was actively abolished in REM sleep. 

In 1957, William Dement, a co-worker of Aserinsky and Kleitman, vigorously investigated the REM sleep-dream connection in humans, and discovered that cats also had periods of brain activation and REM in their sleep. This provided the experimental model necessary for investigation of the cellular and molecular basis of brain activation in sleep, and the chance to integrate phenomena at the level of cells and molecules with the EEG and the distinctive forms of mental activity in human sleep. We didn t need to know whether cats dreamed to make this integration. All we... 

In terms of the important scientific use to which we could put animal sleep in the study of human dreaming, it makes little difference what the answer to the question about animal dreams might be. All we need know, in order to learn from our animal colleagues, is that they have the same kind of brain activation in their sleep as we do. We then go on to make the fairly safe assumption that animals have the same mechanisms of brain activation in sleep as we do. 

Although counterintuitive, the discovery of brain activation in sleep was rapidly accepted by those dream scientists who had sudden and transformative ah-ha experiences when they read about it. In the ensuing excitement about the similarities between waking and dreaming consciousness, few stopped to wonder what bit of this sleep-dependent brain activation could account for the difference, which, after all, is every bit as important as the similarities ... 

Now, you might say that we have come a long way from dreaming and even from brain activation in sleep, but I don t think so and I hope that a moment s reflection will show you why. To explain why sleep normally defends us from such fates, we must assume that it is the change in brain state, with all its chemical and electrical transformations, that keeps us healthy. A second reason, admittedly theoretical, is that our drive to sleep is so intense, so demanding, and so enduring that it must have important survival functions. 

Sleep walking, sleep talking, and tooth grinding are three of the so-called parasomnias, movement (or motor) behaviours that occur unexpectedly during sleep. When we recall that the answer to so many of our questions has been brain activation in sleep, it will not... 

Now brain activation in sleep can be seen in an entirely new light. It does - sometimes at least - reflect previous experience. Of course it does, you say. I always thought that would be true. But how could you be sure And how could you find out exactly what was done with that day s experience by your brain without a label or a marker Now that we have one, we are in a much stronger position to ask such questions as the following ... 

What we need now is a set of truly general rules that help us to accept our dreams, our fears, and our rages for what they are expressions of brain activation in sleep and in waking that have their own deep and compelling reasons for being. In the twenty-first century we will learn much, much more about these deep reasons from brain research. 

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