Activation Synthesis Theory

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
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 sleep until the body is physiologically sound. Circadian theorists believe that we become tired when it gets dark outside, the function of sleep is to preserve energy, sleep depends on whether one is vulnerable to predators, and sleep is based on an internal timing mechanism. The main difference between recuperation and circadian theories is that circadian theory focuses primarily on when a person sleeps and the circadian sleep cycles, while recuperation theory focuses primarily on why we sleep and the recuperative value of