The Importance Of The Sleep Cycle
It's important to understand the sleep
cycle in order to understand the dreaming process. Before we can gather
information from our dreams, we need to understand where those dreams come
from, and to do that we must understand the various stages of sleep and
how they fit together.
The sleep cycle consists of four
individual stages, and every person goes through all four stages each and
every night. The length of each cycle varies from person to person, but
every human being experiences all four stages of sleep every
night.
In general, the dreams
that are most likely to be remembered are those that take place the
closest to waking. Dreams that take place earlier in the night
are almost never remembered. The one exception to this rule is those
dreams that are disturbing enough to wake the dreamer. If a dreamer
awakens in the middle of dream sleep, as with a particularly vivid
nightmare or a dream about falling, he or she will most likely remember
vividly every detail of the dream.
Let us take a look at the four
individual stages of sleep, starting, logically, at stage
one.
Stage 1:
The initial stage of sleep
is a very light sleep, and the slightest disturbance can wake the
dreamer at this stage. The first stage of sleep usually lasts for only a
few minutes, and most sleepers move on quickly to stage two.
Stage 2:
The second stage of sleep
is much deeper, and it is much harder to wake the sleeper up at
this point. While the dream state begins in stage two, there are usually
no clearly formed images at this point. Instead dreams in stage two
consist mainly of vague ideas and images floating around the
mind. After stage two is completed, the dreamer moves quickly on to
stage three.
Stage 3:
The third stage of sleep
is even deeper than the second stage. At this stage, the muscles
in the sleepers body have relaxed, and the heart rate and respiration rate
have both slowed down. The sleeper's blood pressure also drops off at this
point, and breathing is typically even and steady. A sleeper in stage
three sleep is very difficult to awaken, and typically waking can only be
accomplished by a very loud startling noise or by shouting the sleeper's
name repeatedly.
Stage 4:
Stage four is the deepest
stage of sleep, and the one in which most dreaming takes place.
During this stage of sleep, it is almost impossible to wake the sleeper.
During stage four of sleep, the sleeper moves in and out of REM (rapid eye
movement) sleep several times. It is during REM sleep that dreaming is
occurring. The eyes move back and forth rapidly under their lids, the
heart beat and respiration spike, and brain wave activities increase. As a
matter of fact, studies have shown that brain wave activity is higher
during dream sleep than it is during normal consciousness.
Most sessions of dream sleep last
for about 10 minutes, after which the sleeper returns to the normal deep
sleep of stage four. The dreamer will cycle back and forth between stage
four sleep and dream sleep several times each night, usually repeating the
process from four to seven times on an average night.
|