Sleeping and Dreaming

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  • Topic: Sleep, Dream, Electroencephalography
  • Pages : 2 (542 words )
  • Download(s) : 65
  • Published : February 27, 2013
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There are four stages of sleep: Stage one shows low-voltage, high-frequency signals on an EEG similar to those produced while awake, though slightly relaxed. There is slow voltage increase with an immediate drop in frequency through development in stages. Stage two is marked by two diverse wave formations called a K complex and a sleep spindle. Stage three is interrupted by an intermittence of delta waves which are great and measured, while stage four is predominantly delta waves. (Pinel, 2007) After a period of interval in stage four, the sleeper returns to an altered stage one; stage one is reformed from the initial stage because subsequent repeats of stage one are obvious by a loss of muscle tone, REM (rapid eye movement), dreams, and an increase in cerebral and autonomic nervous system activity. The balance of sleep is spent broken between the stages. Each cycle through sleep stages last approximately 90 minutes, and as sleep continues, the time spent in stage one is increased with a decrease in time spent in the other three stages.  There are five common beliefs about dreaming; these are that: external stimuli can be incorporated into dreams; dreams are very brief; some people do not dream; penile erections are due to dreams that are sexual in nature; and sleep talking and sleepwalking happen during dreams (Pinel, 2007). Two common theories about dreams are the Freudian theory that dreams are repressed desires and Hobson's activation-synthesis theory that dreams are the result of random brain stem circuits actively overwhelming the cerebral cortex (Pinel, 2007). The two common sleep theories that attempt to address the purpose of sleep and sleep habits: recuperation and circadian. Recuperation theory works off the principle that sleep restores the body to a state of and sleep renovates energy levels. Recuperation theorists believe that the very act of being woken causes one to become tired and sleep deficiency may cause developmental disorders so that we...
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