By Drew Brenner

The four stages of sleep during which the sleeper does not experience rapid eye movement (REM) sleep. They average sleep cycle lasts about 90 to 100 minutes. Non-REM dreams are more likely to consist of brief, fragmentary impressions that are less emotional and less likely to involve visual images than REM sleep dreams.

What exactly is the difference between REM & Non-REM Sleep?

REM Dreams and Non-REM dreams are very different from each other in a few major ways. The first difference between the two is Non-REM dreams consist of brief, fragmentary impressions. They are also less likely to involve visual images compared to REM sleep, and are more frequently forgotten. Non-REM dreams are like thinking about something during the day for a brief period of time while REM dreams are comparable to thinking deeply about something. REM sleep consists of about two hours a night while Non-REM sleep lasts about four to six hours.

Does the Type of Sleep we Receive change with Age?

According to the chart above it does. You receive more and more Non-REM sleep the older you get. You also sleep less and less the older you get. This information and chart was gathered from The Rock Hill School District Three Internet Site.

The Five Stages of Sleep

As people sleep they go through five different stages. These stages are broken down separately because there are changes in your brain waves. About every 90-100 minutes people pass through all 5 stages.

1) In stage one of the sleep cycle brain waves are referred to as theta waves. They consist of a 4-7 cycle per second rhythm. (Non-REM Sleep)

2) In stage 2 of sleep, the brain generates sleep spindles. Spindles are a 12-14 rhythm that lasts a half of a second. Sleep talking usually occurs during stages 1 and 2 of sleep. Sleep talking is mumbled and usually not understandable. (Non-REM Sleep)

3) Delta waves are produced from the brain in the third stage of sleep. These brain waves become slower when the sleep cycle begins. During this cycle your heart rate, blood pressure, and arousal decline. (Non-REM Sleep)

4) Stage four is very similar to stage 3 because Delta waves continue in the brain. During this stage of sleep most dreams and nightmares occur. (Non-REM Sleep)

5) In stage five your breathing becomes irregular and more rapid. Your heartbeat rises and your eyes dart around in a momentary burst of activity while your eyelids are closed. This is called REM sleep (REM Sleep)

Sleep is divided into REM and non-REM types. Non-REM sleep consists of the lighter stages--stage 1 and stage 2--and a deep form of sleep known as Delta (or slow-wave) sleep, which comprises stages 3 and 4. Most of the first third of the night, non-REM delta sleep predominates. After about an hour and a half in most normal people, the first REM period begins, and this alternates with non-REM sleep throughout the night. Most people have 4-5 REM periods in a given night. It is not known whether REM or delta sleep is deeper, but it generally requires more stimulation to arouse the sleeper from delta sleep.

Which kind of sleep is better REM or Non-REM?

Even though REM sleep is a much deeper sleep it is not shown to be any better than Non-REM sleep. The reason for this is our body needs both kinds of sleep to be fully rested. Without one the other would never be as effective.

For more information, please see the related weblinks on the Stages of Sleep Homepage.