There are four different stages of sleep EEG that an individual goes through during their sleeping cycle (Pinel, 2007). Stage one of sleep consists of low voltage, high frequency signal (Pinel, 2007). As a person begins to advance towards stage two of sleep the EEG voltage increases and the EEG frequency decreases (Pinel, 2007). In stage two of sleep the EEG has slightly higher amplitude and a lower frequency with two distinctive characteristic wave forms the K complexes and sleep spindles (Pinel, 2007). In stage three of sleep there are occasional delta waves which are the largest and slowest EEG waves (Pinel, 2007). Stage four of sleep is predominated by delta waves (Pinel, 2007).
In addition, it is important to point out that there are two different stage one of sleeping. There is the initial stage one EEG that has already been described and then there is emergent stage one EEG that an individual returns to after completing stage four of sleep (Pinel, 2007). In the emergent stage one it is accompanied by REM or rapid eye movements and by the loss of tone in the body core muscles (Pinel, 2007). It has also been discovered that during the REM emergent stage one of sleep that people dream (Pinel, 2007).
Beliefs Concerning Dreams and Dreaming
Dreaming is a subject that is fascinating and not entirely understood leaving it open to different beliefs and theories. A few common beliefs have been addressed and proven to be inaccurate. One such belief is that external stimuli can become incorporated into their dreams (Pinel, 2007). Another belief is that dreams only last an instant, though research suggests dreams run on “real time” (Pinel, 2007).
Still others believe they do not dream at all even though they spend just as much time in REM as dreamers do (Pinel, 2007). People also have a tendency to believe that sleep talking and sleepwalking only happen during dreaming which is not true (Pinel, 2007). Lastly there is the belief that penile erections indicate dreams of sexual content, however, this no more true than dreams without sexual content (Pinel, 2007).
Dreaming Theories
Along with the discovery of dreams came theories of interpreting dreams. One interesting theory that became the basis for many interesting stories was produced by Sigmund Freud. The Freudian theory of dreams has no convincing evidence but suggests that an individual’s dreams are triggered be improper or repressed wishes that are usually of sexual nature (Pinel, 2007).
A more modern theory on dreams is Hobson’s activation-synthesis theory. This theory is based on the observation during REM sleep that many brain-stem circuits bombard the cerebral cortex with neural signals (Pinel, 2007). The majority of the information that is supplied to the cortex during the REM sleep is random, the effort of the cortex to make sense of this information results in dreams (Pinel, 2007).
Though I am a fan of Sigmund Freud and his work, when it comes to dreams I have to agree with Hobson’s theory. For starters there is evidence that our brain-stem circuits do in fact become active while we dream. This also gives a better explanation of why our dreams incorporate things we have done, thought about, or seen that day or in the last few days. In addition, this theory also maintains the theory that dreams still have meaning. I agree with Hobson’s theory because it covers all the bases when it comes to dreams and interpreting them.
Sources
- Pinel, J. P. J. (2007). Basics of Biopsychology. Boston, MA: Allyn and Bacon.
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