Discuss sleep in terms of the normal sleep cycle. Please be sure to address the stages of sleep and physiological correlates associated with each stage.
The normal sleep cycle is in four stages. Alpha waves begin the sleep process, there are highs and lows from 8- to 12-Hz EEG waves considered low-voltage, high-frequency waves of “dozing off”, as we fall asleep, we move in to the stage 1 of sleep. The stage 1 sleep EEG is a type of low-voltage, high-frequency signal with a gradual increase in EEG voltage and a decrease in EEG frequency progressing from stage 1 through stage 4. Stage 1 sleep is where REM sleep takes place. The brain activity during this time increases in various parts of the brain primarily in the cerebrum, with an increase …show more content…
The K complex is a large negative wave with an immediate single large positive wave, and each sleep spindle rises and then lowers from 12- to 14-Hz waves. Breathing and heart rates slow during this stage. (Pinel, 2014)The stage 3 sleep EEG, has occasional delta waves which are the largest indicators of EEG often referred to as the deep sleep. Stage 4 is very deep sleep with limited muscle activity and delta waves. During our sleep, once we reach stage 4 EEG, we then travel back through the stages to stage 1. (Pinel, 2014)Each sleep cycle is about 90 minutes long which is controlled by the biological clock in the caudal brain stem. REM sleep is controlled by various nuclei located within the caudal reticular formation. The remainder of the night is spent going back and forth through the sleeping stages. Stages 3 and 4 of sleep are considered slow wave states from their types of delta waves. (Pinel, …show more content…
Some believe that dreams last only an instant however research has been able to prove they run on real time. Some people say they have no dreams at all yet have reported them when being woke up during REM sleep. Some believe that penile erections are indicative of sexual dreams but even infant have this occurrence. Many believe that sleepwalking and talking happen during REM sleep but in reality it can occur at any stage, especially not during REM since core muscles are in a relaxed state. (Pinel, 2014) Freud thought that that by understanding people and dealing with their psychological problems was founded in the meaning of their latent dreams. Hobson’s activation-synthesis theory is the most recent dream theory as it bases itself on content reflecting the cerebral cortex with regards to the signals it receives from the brain stem during REM