Module 9: Sleep and Dreams

Sleep

A periodic, natural loss of consciousness - as distinct from unconsciousness resulting from a coma, general anesthesia, or hibernation

How long is the circadian rhythm cycle?

24 hours

How long is our sleep cycle?

90 minutes

Circadian Rhythm

Our biological clock; regular bodily rhythms that occur on a 24 hour cycle

REM (rapid eye movement) Sleep

Eyes move rapidly under the eyelids and the person is typically experiencing a dream; AKA paradoxical because the muscles are relaxed but other body and brain systems are active

Alpha Waves

Brain waves that indicate a state of relaxation or light sleep

N1 Sleep

Slowed breathing and irregular brain waves

Hallucinations

A false perception - sensory experiences without sensory stimulation - such as seeing or hearing something in the absence of actual stimuli

Microsleeps

Brief sidesteps into sleep lasting only a few seconds

Sleep Deprivation

Any significant loss of sleep

Adaptive Theory

Proposes that animals and humans evolved sleep patterns to avoid predators by sleeping when predators are most active

Restorative Theory

Sleep is necessary to the physical health of the body and serves to replenish chemicals and repair cellular damage

NREM

Any of the stages of sleep that don’t occur in REM

Theta Waves

Brain waves indicating the early stages of sleep

Delta Waves

Long, slow waves that indicate the deepest stage of sleep

Functions of sleep?

Protection, recuperation, restoration, supporting growth, and creative thinking

N1 Stage

Light sleep and may experience hypnagogic images or hypnic jerk

N2 Stage

Sleep spindles - brief bursts of activity only lasting a second or two

N3

Deepest stage of sleep, body at lowest functioning level, and growth occurs

REM Rebound

Increased amounts of REM sleep after being deprived of REM sleep on earlier nights

What affects our sleep patterns?

Genetic influences, cultural/social, presence of light, SCN, irregular sleep schedule, night shift work

Sleepwalking

Episode of moving around in one’s sleep - occurs in deep sleep

REM Behavior Disorder

Paralysis during REM sleep is incomplete or absent allowing person to act out dreams

Night Terrors

The person experiences extreme fear and screams or runs around during deep sleep and doesn’t wake fully (twilight)

Insomnia

The inability to get to sleep, stay asleep, or get a good quality of sleep

Sleep Apnea

Disorder in which the person stops breathing for nearly half a minute

Narcolepsy

Sleep disorder in which a person falls immediately into REM sleep during the day without warning

Freud

Dreams as wish fulfillment

Manifest Content

The dream itself

Latent Content

The true, hidden meaning of the dream

Why do we dream?

Satisfy wishes, file memories, develop/preserve neural pathways, make sense of neural static, and reflect cognitive development

Hypnosis

State of consciousness in which the person is especially susceptible to suggestion

What are the four elements of hypnosis?

Focus on what’s being said, told to relax/feel tired, tell person to let go, and told to use vivid imagery

Hypnotic Susceptibility

Degree to which a person is a good hypnotic subject

Hypnosis As Dissociation

Hypnosis works only in a person’s immediate consciousness, while a hidden observer remained aware of all that was going on

Social Cognitive Theory of Hypnosis

People who are hypnotized are not in an altered state, but are merely playing the role expected of them in the situation