It is thought that for cerebral representations to be modified or updated, the cells over the whole cerebral cortex should become modifiable, and that at such times ordinary information (from the external environment) should be rigorously excluded. The time when such a condition normally exists is during sleep.
It is thought that mental activity takes place during D/REM and S/NREM sleep, but that the mental activity during D/REM sleep is the most dream-like, while that occurring during S/NREM sleep is much more awake-like. Consequently, it is the D/REM sleep phase that is thought to be correspondent with the actual experience of dreaming, while the subsequent S/NREM phase is correspondent with mental activity related to the experience of the preceding dream phase. (Marjorie L. Rand, 2002)
Normally, dream sleep appears at 70-90 minute intervals throughout the sleep period in adults. There is, however, evidence that the physiological and neurophysiological activity normally correspondent with dream sleep also occurs with the same periodicity, but less intensely or evidently, throughout the awake state.
Underlying the two psychological systems considered to interact during the process of dreaming may be two physiological or neuroanatomical systems. Dream sleep may involve the preponderant or emergent activity of a neuroanatomical region different from the region that normally is preponderantly active in the awake state. (Cheryl H. Alexander, 2000).
One factor thought to contribute to the onset of sleep, particularly dream sleep, is a reduction of externally generated stimuli that reach the higher and conscious level of the brain. As a result of this reduction there may be facilitated a release of internally generated past impressions or memories from within the lower neuroanatomical and unconscious levels. Within the higher, or cerebral, level of the brain, the emergence of information released from the lower level may also involve a decreased activity of processes, or switching off of the system that would normally in the awake state inhibit such preponderant emergence. (Edmund T. Rolls, 2000).
Relative to the S/NREM sleep phase, the D/REM sleep phase is accompanied by increased cerebral blood flow; increased activity of the autonomic nervous system; increased "spontaneous" activity of the reticular formation; a higher response threshold in the midbrain reticular formation to auditory as well as direct stimulation; and a higher threshold for behavioral awakening. (Simon J. Sherwood, 2002).
Among the phenomena evident during D/REM sleep are cerebral desynchronization; hippocampal theta waves of 5-6 Hertz, a depression of spontaneous and reflex activity in the muscles and a general atonia, especially of the antigravity muscles. The preceding phenomena constitute a tonic background on which are superimposed the following phasic phenomena: large amplitude waves occurring in the pontine reticular formation, lateral geniculate nuclei and occipital cortex, which are referred to as PGO activity and which normally occur coincidentally with REM bursts; short-term increases in the frequency of the hippocampal theta rhythm; increased muscle activity and myoclonic twitches; and short fluctuations within the autonomic nervous system. Also involved in D/REM sleep are the parietal lobe, the temporal lobe, the cerebral limbic regions, and the pulvinar of the thalamus. (Elena Miro, M. Carmen Cano, Lourdes Espinosa-Fernandez, Gualberto Buela-Casal, 2003).
Both the tonic and phasic phenomena of dream sleep may be regarded basically as an ascending excitatory component ...
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“Neurophysiology of Sleep Essay Example | Topics and Well Written Essays - 1750 Words”, n.d. https://studentshare.net/psychology/289699-neurophysiology-of-sleep.
(Cherry, 2011) mentions that stage 1 characterizes the beginning of sleep in which one drifts in and out of sleep, while the muscle activity gradually slows down. Stage 2 refers to the stage in which the eye movement altogether stops and brain waves get slower, while there may occur an occasional burst of hurried brain waves.
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This is usually accompanied by dreaming when someone awake; hallucinations in some people. This is exhibited majorly in seeing other people in the room, touch sensation, footsteps hearing, hearing people call you among others. In the article, he identifies that chronic sleep paralysis only affect around six percent of the general adult population.
There are states of partial consciousness which can be revoked by stimulation. A person spends about one-third of his life whilst sleeping. Sleep is significant for every person because it recharges his body and mind. It makes him fresh because it is a crucial ingredient that goes into delivering work regimes on an out and out basis.
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The psychological effects resulting from sleep deprivation include the aching muscles which suggest that human muscles require a certain amount of sleep before they could be put to good use again.
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to Sofaer, pain refers to an unpleasant sensory and emotional experience that is usually concomitant to actual or potential damage to the tissues or described in terms of such damage. In medicine, pain can be referred to as a sensation that hurts thus, causing discomfort, agony
Furthermore, the patient has long cessation during breathing and hypertension. These are all signs which can be found in Obstructive Sleep apnea. Disruptive snoring is common in the majority of patients with this disorder