The Science of Sleep Flashcards
Circadian Rhythm
- Cyclical changes that occur on a roughly 24-hour basis in many biological processes
- Regulated by the Suprachiasmatic Nucleus (SCN)
Suprachiasmatic Nucleus (SCN)
- Located in the hypothalamus
- Brain’s “Biological clock”
- Pineal gland releases a hormone called melatonin
How much sleep do we need?
An average person requires 7-10 hours per night
Amount of sleep needed depends on….
- Age
- Health
- Quality of Sleep
- Genetics
- Species
Sleep deprivation can result in…
- Difficulties learning
- Poor attention
- Lethargy
Sleep deprivation is associated with various adverse health outcomes…
- Weight gain
- Diabetes
- Heart problems
- Weakened immune systems
Stages of Sleep
- Awake and Alert
- Calm Wakefulness
- Stage 1
- Stage 2
- Stage 3 & 4
- Stage 5 (REM sleep)
Awake and Alert
- Beta waves ( approx. > 13 waves per second )
Calm wakefulness
- Alpha waves ( approx. 8-12 waves per second )
Stage 1
- Theta waves ( 4-7 waves per second )
- Myoclonic jerks
- Hypnagogic imagery
Stage 2
- Sleep Spindles: Short burst of neural activity
- K-Complexes: A large waveform that occurs intermittently
Stages 3 & 4
- Delta waves (1-2 waves per second)
- Stage 3 < 50% of waves are delta
- Stage 4 > 50% of waves are delta
- “Deep sleep” is required for feeling well rested
- Time spent in deep sleep declines with age
Stage 5 (REM sleep):
- Rapid eye movement (REM): Darting of the eyes underneath closed eyelids during sleep
- Stage of sleep during which the brain is most active and during which vivid dreams occur most often. Rebounds when REM sleep is lost
Non-REM sleep (NREM)
Stages 1-4 of the sleep cycle during which rapid eye movements (REM) do not occur and dreaming is less frequent and vivid
Insomnia
- Difficulty falling and STAYING asleep.
~ Regularly takes more than 30 minutes to fall asleep
~ Waking up too early in the morning
~ Waking up during the night and having trouble returning to sleep
~ Factors such as age, drug use, exercise, mental status, and bedtime routines may contribute to insomnia
Behavioural Treatment for Insomnia
- Make sure to have a consistent wake cycle
- Go to bed ONLY when you are (feel) tired and ready to sleep ~~ if you are in bed and not sleeping get out of bed
- Only use your bed for sleeping purposes
- Regularly exercise
- Avoid alcohol and caffeine in the evening
Pharmacological Treatment for Insomnia
- Can be addictive
- Has adverse side effects
- May lead to rebound insomnia
Narcolepsy
- A sleep disorder characterized by an irregular control of sleep-wake cycles
Symptoms of Narcolepsy
- “Sleep attacks”
- Cataplexy
- Sleep Paralysis
- Hypnagogic (sleep onset) and Hypnopompic (sleep offset) hallucinations
- Disturbed nighttime sleep
Causes and Treatment for Narcolepsy
CAUSES: Insufficient hypocretin producing neurons in the hypothalamus
TREATMENT: Stimulants and behavioural strategies
(Obstructive) Sleep Apnea
Disorder caused by a blockage of the airway during sleep. Results in a daytime fatigue
Sleep Apnea
Creates: Night sweats, weight gain, hearing loss, irregular heartbeat and raises the risk of death
Treatment: Weight loss, CPAP air mask
Night Terrors
- A sudden waking episode which is characterized by screaming, perspiring and confusion which is followed by a return to deep sleep
- Lasts a few minutes
- Happens in stage 3&4
- Harmless
- Treatment: Get old
Sleep Walking
- Somnabulism
- Walking while fully asleep
- Occurs during deep sleep phase
- Usually harmless
- Person is unaware that they have done it
- Occurs more often in children
- Perfectly fine to wake up a sleep walker
Dreams
- Many people dream, but not many can recall
- 0.38% of people have been found to NEVER dream
Dreams: Cross-Cultural Similarities
- Typically more negative than positive
- Ratio of make to female characters in a dream
~ 1:1 for women
~2:1 for men - Dream content is more continuous with past or present pre-occupations of the dreamer
Dreams - Freud
- Dreams reflect “wish-fulfillment” of unconscious desires
~ Prevents unconscious urges from ruining sleep. - These primitive unconscious urges/desires are expressed within the dream and require “interpretation”
Manifest Content
The raw facts and details about the dream
Latent Content
The underlying meaning about details within the dream
Dreams: Activation Synthesis Theory
