Consciousness, perception and body control in sleep
Study of sleep and dreaming seems to be a promising way towards the understanding of such intriguing phenomena, as human “consciousness” and “self awareness” – unlike in wakefulness, they can take up many different surprising shapes in sleep. Common opinion of sleep as a “state of unconsciousness” is, basically, incorrect – often consciousness can be retained in sleep; on the other hand, the feeling of “self awareness”, when experienced in a dream, can be utterly wrong.
Sleep can be considered a combination of several different phenomena – general relaxation, loss of consciousness, sleep paralysis, and various degrees of external stimuli perception distortions. This combination vary a lot with changes in sleep cycle phase – for instance, paralysis is usually absent in NREM phase, the body is just very relaxed; traces of consciousness, if present, can be extremely dim and slow, but usually quite adequate, as well as the traces of external situation perception. On the contrary, in REM phase with dreams body is paralyzed – mind has almost no control over it, consciousness can be as bright as when fully awake, but absolutely inadequate, and perception of real external cues can be distorted very much, kind of woven into the general pattern of “sleep hallucination”.
Here are some curios states of brain, experienced in REM phase:
- Ordinary dream: a feeling similar to consciousness or self awareness is undoubtedly present, but totally inadequate – one takes the dream for real. Body is paralyzed, external cues are perceived distortedly.
- Dreaming of insomnia: in many cases people complain that they “could not sleep all the night”, but, nevertheless, their somnograms show normal sleeping cycles. This can only mean that they were sleeping and dreaming of their lying in the bed awake. Generally, this dream – of lying in the very same bed in the very same room – was found extremely common, people just don’t notice it, as it is so hard to distinguish from reality. Inadequate consciousness, paralysis and perception distortions were proved to be just like in a normal dream.
- Classic lucid dream: one sees a dream and at the same time realizes, that he/she is sleeping, and having a dream: – consciousness is clear enough and perfectly adequate, but the body is paralyzed and external cues are not perceived adequately. Often in this case the feelings become extremely bright and realistic, quite undistinguishable from real; often this is a very positive experience, and many training techniques, some using electronic equipment, were developed to achieve it. A number of interesting experiments can be conducted in this state.
- I-want-to-run-but-I-cannot-move sort of nightmare: consciousness inadequate and body paralyzed like in ordinary dream, but some external cues are perceived correctly – the mind is duly informed that the body is not, in fact, moving.
- Similar to the above, but with adequate consciousness: I try to move in a dream and find my body paralyzed; this makes me realize that I am sleeping and having a dream; I understand that I must be lying in my bed, but cannot be sure of what is going on around it, senses are not to be trusted, body paralyzed – a helpless and uncomfortable condition, too.
- When I wake up in the morning, I am unable neither to move nor to speak for some time, complained one teenage girl. Sounds like paralysis is still present, but perception is more or less correct. Interesting dilemma with her consciousness adequacy – to the one hand, she can be considered still asleep, mistakenly thinking herself awake; to the other hand she can be considered awake, but paralyzed – this is exactly her own idea of this condition, – then her consciousness is perfectly right.
The listed above conditions can occur in normal and healthy brain, but the list can be logically continued to include
- various conditions with inadequate consciousness and/or distorted perception, but with sleep paralysis absent. One would be able to walk and talk, but would see things and hear voices, and/or react inadequately to real stimuli – it would look like many known mental disorders such as schizophrenia. (Classic sleep walking is probably a different thing, it is believed to occur in NREM phase, when consciousness is nearly absent).
And, finally, we can include the
- state of normal wakefulness, with its adequate consciousness, correct perception and absence of sleep paralysis.