Section 4: Sleep and Dreaming (Module 8)

dreams

A series of images, ideas, emotions, and sensations occurring involuntarily in the mind during certain stages of sleep. 2. A daydream; a reverie. 3. A state of abstraction; a trance: wandering around in a dream.

Stage 2

In stage 2, eye movement stops and brain waves become slower with only an occasional burst of rapid brain waves

Stage 4

In stage 4, the brain produces delta waves almost exclusively. Stages 3 and 4 are referred to as deep sleep or delta sleep, and it is very difficult to wake someone from them. In deep sleep, there is no eye movement or muscle activity. This is when some children experience bedwetting, sleepwalking or night terrors. In 2008 the sleep profession in the US eliminated the use of stage 4. Stages 3 and 4 are now considered stage 3.

REM sleep

In the REM period, breathing becomes more rapid, irregular and shallow, eyes jerk rapidly and limb muscles are temporarily paralyzed. Brain waves during this stage increase to levels experienced when a person is awake. Also, heart rate increases, blood pressure rises, males develop erections and the body loses some of the ability to regulate its temperature. This is the time when most dreams occur, and, if awoken during REM sleep, a person can remember the dreams. Most people experience three to five intervals of REM sleep each night.

theories of sleep

Recharge,take out the trash,record keeping, dreaming

sleep stages

Usually sleepers pass through five stages: 1, 2, 3, 4 and REM (rapid eye movement) sleep. These stages progress cyclically from 1 through REM then begin again with stage 1

Stage 3

When a person enters stage 3, extremely slow brain waves called delta waves are interspersed with smaller, faster waves.

Stage 1

Stage 1 is light sleep where you drift in and out of sleep and can be awakened easily. In this stage, the eyes move slowly and muscle activity slows. During this stage, many people experience sudden muscle contractions preceded by a sensation of falling.

narcolepsy

a condition characterized by an extreme tendency to fall asleep whenever in relaxing surroundings

nightmares

a dream occurring during rapid eye movement (REM) sleep that results in feelings of strong terror, fear, distress or extreme anxiety. This phenomenon tends to occur in the latter part of the night and oftentimes awakens the sleeper, who is likely to recall the content of the dream.

insomnia

habitual sleeplessness; inability to sleep

non-REM sleep

non-rapid eye movement) sleep is dreamless sleep. During NREM, the brain waves on the electroencephalographic (EEG) recording are typically slow and of high voltage, the breathing and heart rate are slow and regular, the blood pressure is low, and the sleeper is relatively still

circadian rhythm

roughly 24 hour cycle in the physiological processes of living beings, including plants, animals, fungi and cyanobacteria. In a strict sense, circadian rhythms are endogenously generated, although they can be modulated by external cues such as sunlight and temperature