Sleep and Dreams Flashcards
Circadian Rhythms
occur on a 24-hour cycle and include sleep and wakefulness.
Controlled by the hypothalamus, specifically the suprachiasmatic nucleus (SCN)
- receives input from the eyes & is especially
sensitive to the light-dark cycles of day and night
- light signals the SCN to tell the pineal gland to
stop the release of melatonin…in darkness SCN no
longer sends messages, increasing melatonin
levels and sleepiness
W= wakefulness
R = REM Sleep
N= NREM sleep stage
Sleep Stage 1
just drifting to sleep, may experience fantastic images
and/or auditory hallucinations, a mix of alpha and theta waves
Sleep Stage 2
more relaxed, clearly asleep and sleep spindles occur
Sleep Stage 3
deepest sleep, hard to awaken… only occurs during the first few cycles of the night, characterized by large delta waves
Sleep Spindles
short bursts of brain activity
REM Sleep – Paradoxical Sleep
After reaching the deepest stage (3), the sleep cycle starts moving backward toward stage 1. Although still asleep, the brain engages in low amplitude, fast, and regular beta waves, much like an awake-aroused state.
REM sleep is characterized by rapid eye movement, which indicates the person having dreams.
REM is considered Paradoxical sleep because the brain is almost as active as being awake, but the body is paralyzed.
Sleep Theories - Sleep Protects
Sleeping in the darkness when predators loom kept our ancestors out of harm’s way.
Sleep Theories- Sleep Recuperates
Sleep helps restore and repair brain (and body) tissue.
Sleep Theories - Sleep Helps Remembering
Sleep restores and rebuilds our fading memories.
Sleep Theories - Sleep and Growth
During sleep, the pituitary gland releases growth hormones. Older people release less of this hormone
and sleep less.
Sleep Disorders - Insomnia
difficulty falling asleep or staying asleep
Sleep Disorders - Narcolepsy
overpowering urge to fall asleep that may occur while talking or standing up.
Experience sleep attacks that usually last 5 minutes or less… this can mean lapsing directly into REM sleep for some people
Sleep Disorders - Night Terrors
Sudden arousal from sleep and intense fear accompanied by physiological reactions (occurs usually during 1st sleep cycle of the night)
* Seems to be related to some fear the child has… but is not the same as a nightmare (bad dream)… just see images
* If not awakened, the child often won’t remember in the morning.
Sleep Disorders - Sleep apnea
failure to breathe when asleep
* Wake up hundreds of times a night so that they will begin
breathing again
* Treatments include weight loss and CPAP machine
Sleep Disorders - Sleep Walking
blank stare, move about in a slow/automatic manner, and may try to eat, dress, or go to the bathroom in the wrong place while still sleeping
* Occurs in stage 3
* Technical name is Somnambulism
Sleep Disorders - REM Behavior Disorder (RBD)
muscles are not paralyzed in REM as they should be, allowing the person to act out their dreams (usually the vivid, violent, intense dreams)
* Seen more often in middle age/elderly men, sometimes linked with Parkinson’s disease.
Dream Theories - Wish Fulfillment
Sigmund Freud suggested that dreams provide a safety valve to discharge unconscious wants & desires.
Dream Theories - information processing
Dreams may help sift, sort, and fix day’s experiences in our memories
Dream Theories - physiological functions
Dreams provide the sleeping brain with periodic stimulation to develop and preserve neural pathways. Neural networks of newborns are fast developing and therefore need more sleep.
Dream Theories - Activation-synthesis theory
Suggests that in sleep the brain engages in a lot of random neural activity. Dreams make sense of this random activity (because the brain doesn’t like randomness)
a. Dreams are the brain’s interpretations of its own activity
b. So… They mean NOTHING!
Dream Theories - Cognitive development
some researchers argue that we dream as a part of brain maturation and cognitive development
Rem Rebound
All dream researchers believe we need REM sleep. When sleep-deprived, and then allowed to sleep again, we show increased REM sleep. This tendency is called REM Rebound.
The manifest content
The manifest content (remembered story-line) is a
a censored version of the dream’s latent content
(underlying meaning of dream).
