Stages of Sleep

stage 1 sleep (NREM)

between wakefulness and sleep; alpha waves in low frequency (8-13 Hz); theta waves are lower frequency (4-7 Hz), higher amplitude than alpha waves

stage 2 sleep (NREM)

the body goes into deep relaxation; theta waves dominate by bursts of activity called sleep spindles and K-complexes

sleep spindle

rapid burst of higher frequency brain waves that may be important for learning and memory

K-complex

high amplitude pattern of brain activity that may in some cases occur in response to environmental stimuli

stage 3 sleep (NREM)

deep sleep, slow-wave sleep; low frequency (less than 3Hz) and high amplitude delta waves; heart rate and respiration slow dramatically

REM sleep

marked by rapid movements of the eye, brain waves are similar to those of wakefulness; dreaming occurs; paralysis of muscle systems excl. circulation and respiration; may be related to learning, memory, emotions, and stress

manifest content

the actual content/storyline of a dream

latent content

hidden meaning of a dream

collective unconscious

a theoretical repository of information believed to be shared by everyone

normal sleep cycle consists of…

5±1× 90 min cycles, stage 3 occurs in first 2-3, REM is 25% of the second half of sleep

insomnia

consistent difficulty in falling or staring asleep

cognitive-behavioural therapy

psychotherapy that focuses on cognitive processes and problem behaciours

parasomnia

REM sleep disorder; unwanted, disruptive motor activity and/or experiences during sleep play a role, e.g. restless leg syndrome

sleepwalking/somnambulism

sleeper engages in relatively complex behaviours ranging from wondering about to driving an automobile; eyes are open but not responsive to communication; slow-wave sleep

REM sleep behaviour disorder

when the muscle paralysis associated with the REM sleep phase does not occur

restless leg syndrome

uncomfortable sensations in the legs during periods of inactivity or when trying to fall asleep

night terrors

sense of panic the sufferer and are often accompanied by screams and attempts to escape immediate environment; appear awake, not responsive

sleep apnea

sleeper’s breathing stops; obstructive = airway becomes blocked; central = signals from brain that regulate breathing cause interrupted breathing

narcolepsy

individual cannot resist falling asleep at inopportune times; associated with cataplexy, which is a lack of muscle tone or muscle weakness, sometimes resulting in paralysis