Changes

==== Sleep in general (verse 35) ====

==== Sleep in general (verse 35) ====

The age-old concepts of sleep (''nidra'') and its different stages such as ''jagrata'', ''swapana'' and ''sushupti'' are comparable to the current concept of sleep and its stages. The problems and pattern of sleep are assessed by observing the activity of brain through Electroencephalogram (EEG) pattern. [70] It is pointed out that wakefulness and stages of sleep have a specific EEG pattern. The wakefulness is associated with Beta and Gama waves frequencies in EEG pattern, which depends on pleasurable or painful stressors of surrounding environment. Stage 1 non-rapid eye movement (NREM) sleep is characterized by slowing down of Beta and Gama wave frequencies, reached to slow down the Alpha wave, and finally reached to Theta wave frequencies in EEG pattern.  At a higher stage of NREM and REM, these brain wave frequencies in EEG pattern gradually decreases, and the person falls into sleep. By observing overall brain activity in EEG pattern, we can say that frequencies of sleep waves are low in wakefulness and it is gradual increases in different stages of sleep. Sleep spindles and K-complexes appeared in EEG pattern in Stage 2 of sleep, while more sleep spindles are observed in Stage 3 of sleep.  The slow wave sleep is also known as high amplitude Delta wave, which is commonly observed in Stages 3 and 4 of sleep in EEG pattern. Low amplitude, mixed frequency waves- a sawtooth wave in EEG pattern observed at REM stage of sleep. [71,72,73]

The age-old concepts of sleep (''nidra'') and its different stages such as ''jagrata'', ''swapana'' and ''sushupti'' are comparable to the current concept of sleep and its stages. The problems and pattern of sleep are assessed by observing the activity of brain through Electroencephalogram (EEG) pattern.<ref>Dement, William; Kleitman, Nathaniel (1 November 1957). "Cyclic variations in EEG during sleep and their relation to eye movements, body motility, and dreaming". Electroencephalography and Clinical Neurophysiology9 (4): 673–690. doi:10.1016/0013-4694(57)90088-3. PMID 13480240. </ref> It is pointed out that wakefulness and stages of sleep have a specific EEG pattern. The wakefulness is associated with Beta and Gama waves frequencies in EEG pattern, which depends on pleasurable or painful stressors of surrounding environment. Stage 1 non-rapid eye movement (NREM) sleep is characterized by slowing down of Beta and Gama wave frequencies, reached to slow down the Alpha wave, and finally reached to Theta wave frequencies in EEG pattern.  At a higher stage of NREM and REM, these brain wave frequencies in EEG pattern gradually decreases, and the person falls into sleep. By observing overall brain activity in EEG pattern, we can say that frequencies of sleep waves are low in wakefulness and it is gradual increases in different stages of sleep. Sleep spindles and K-complexes appeared in EEG pattern in Stage 2 of sleep, while more sleep spindles are observed in Stage 3 of sleep.  The slow wave sleep is also known as high amplitude Delta wave, which is commonly observed in Stages 3 and 4 of sleep in EEG pattern. Low amplitude, mixed frequency waves- a sawtooth wave in EEG pattern observed at REM stage of sleep.<ref> 71. BARKER, W; BURGWIN, S (1948 Nov-Dec). "Brain wave patterns accompanying changes in sleep and wakefulness during hypnosis." Psychosomatic Medicine10 (6): 317–26. PMID 18106841. </ref> <ref>Jankel, WR; Niedermeyer, E (January 1985). "Sleep spindles.". Journal of clinical neurophysiology: official publication of the American Electroencephalographic Society2 (1): 1–35. PMID 3932462. </ref> <ref>Loomis, A. L.; Harvey, E. N.; Hobart, G. A (1938). "Distribution of disturbance-patterns in the human electroencephalogram with special reference to sleep". Journal of Neurophysiology1: 413–430.  </ref>

==== Sleep regulation (verse 39-43) ====

==== Sleep regulation (verse 39-43) ====