Professor Antonio Dzadra and his colleagues at the University of Montreal (Canada) reviewed the work of somnambulism made over the past fifteen years, and came to the conclusion that some of the concepts of this intriguing disorder sleep no more than myths.
Episodes of somnambulism is usually too short to man managed to hurt yourself. (Photo by Rainer Holz.)
For example, it is believed that somnambulism affects only children 6-12 years, and the cases in which this disorder manifests itself in adults — a rare exception. That is, the formation of the brain that occurs during puberty, as if frees man from walking in his sleep. But it turns out, this is not quite true: with age the probability of somnambulism is indeed falling, but in 25% of cases, the person continues to sleepwalk and after puberty. The disappearance of the same somnambulism in adults, researchers attributed to the fact that as we age we have reduced the proportion of deep slow-wave sleep, during which just pulls wander through the area.
Sleepwalking in children and adults have the same features: the part of the brain while asleep, a part — is awake. Waking part is responsible for appropriate behavior: a person opens and closes the door, washes his hands, rises or descends the stairs, his eyes are open, he can even get to know people. However, the self-consciousness in this changed and the reaction of the surrounding unusual and illogical.
In general, the authors suggest that partial sleep, when the brain is not fully asleep — this is the essence of somnambulism. And this, incidentally, explains and partial amnesia sleepwalkers: people do not really remember what he was doing at the time, but something in his memory remains. And some may even remember what they were thinking or feeling at that moment, although this improvement is the memory of sleepwalkers, again with age. And it is strongly at odds with the generally accepted notion that a sleepwalker not remember ever anything of his nocturnal adventures.
The researchers also strongly disagree with the fact that everything they do somnambulist, committed by them "on automatic." That is, at the time of his, it seems, quite unconscious of wandering people fully understand the causes and consequences of their actions, and then to explain why he did it, but not this. Conventional logic in his actions, maybe it does not work, but its own cause-and-effect relationship, albeit arbitrarily bizarre, in deeds and thoughts of a sleepwalker is still there.
For example, a man in his sleep gets up, takes a dog that is sleeping next goes to the bathroom and dip the dog in the water. The act seems pointless, but then the explanation still is: sleeping it seemed that dog is on fire! That is, as we see, has its own logic here present. In this episode of somnambulism in most cases are very short, so that a person does not have time to harm themselves or others (although there are exceptions, once a person in a dream sat in the car and drove off, but because more and killed a couple of people!).
Another common misconception is that sleepwalking is not associated with how a person feels while awake. In fact, about half of sleepwalkers feel very sleepy during the day. Younger people can successfully mask it, but in the special tests their reaction is still significantly worse than those who do not suffer from somnambulism.
As to the mechanisms and causes of somnambulism, the authors of the work suggest that the reason is not so much the difficulty of the transition from wakefulness to sleep, but in the structural features of the dream itself. Slow-wave sleep is fragmented sleepwalkers short (3-10 s) episodes of increased activity, as if arousals. Because of this reduced and the restorative function of sleep, but because people suffering from somnambulism, I want to sleep at an inopportune time. And, of course, it's not complete without a genetic predisposition: in 80% of cases when a person walks in his sleep, his family has a rich history of somnambulism. However, usually somnambulism genes themselves can not be involved, for this they need or stress, for example, chronic sleep deprivation.
The study is published in the journal Lancet Neurology.
Adapted from the University of Montreal.