Course: PSYC*1000 (DE)
Professor: Harvey Marmurek
Schedule: Summer, 2012
Textbook: Psychology – Tenth Edition in Modules authored by David G. Myers
Textbook ISBN: 9781464102615
Module 08: Sleep and Dreams
How do our biological rhythms influence our daily functioning?
• Thinking is sharpest and memory most accurate when we are at our daily peak in circadian arousal.
• About age 20, become larks; older adults are definitely larks
• Morning types tend to do better in school, to take more initiative, and to be less vulnerable to depression.
What is the biological rhythm of our sleeping and dreaming stages?
• Cycle through four different sleep stages about every 90 minutes
o Armond Aserinsky 1952 – father Eugene
o REM – rapid eye movement sleep
o Alpha waves – wake but relaxed sleep = transition of slowed breathing and irregular brain waves
o NREM-1: brief; images resembling hallucinations – falling or floating – hypnagogic
o NREM-2: 20 minutes; sleep spindles – burst of rapid, rhythmic brain-wave activity; awakened
without too much difficulty but clearly asleep
o NREM-3: 30 minutes; slow delta waves, hard to awaken
• REM Sleep
o Spend half your night in NREM-2
o REM – 10 minutes; heart rate rises, breathing becomes rapid and irregular, eyes dart around
o Brain’s motor cortex is active during REM sleep,, but brainstem blocks its messages
o Muscles relaxed – sleep paralysis
o As night wears on – NREM-3 gets shorter and NREM-2 gets longer
Safety in numbers – why would communal sleeping provide added protection or hose whose safety depends upon
vigilance, such as soldiers?
With each soldier cycling through the sleep states independently, it is very likely that at any given time at least one
of them will be awake or easily wakened in the event of a threat.
Match cognitive experience with the sleep stage:
NREM-1 – fleeting images
NREM-3 – minimal awareness
REM – story-like dream
What are the four sleep stages, and in what order do we normally travel through those stages?
NREM-1, NREM-2, NREM-3, REM *Normally we move through 1 then 2, then 3 then back up through 2 before we
experience REM sleep
How do biology and environment interact in our sleep patterns?
• Sleep patterns are genetically influenced
• Genes that regulate sleep in humans and animals
• Sleep patterns are also culturally influenced
• Suprachiasmatic nucleus (SCN) – grain-of-rice sized cell clusters in hypothalamus – increase brain’s pineal
gland to decrease production of sleep-inducing melatonin
The (suprachiasmatic) nucleus helps monitor the brain’s release of melatonin, which affects our (circadian) rhythm. What are sleep’s functions?
• Protects - sleep pattern tends to suit ecological niche
• Helps us recuperate – restore and repair brain tissue; when consciousness leaves your house, brain
construction workers come in for a makeover
• Helps restore and rebuild fading memories of the day’s experiences – strengthens and stabilizes neural
• Feeds creative thinking – dreams can inspire; boosts thinking and learning
• Supports growth – pituitary gland releases growth hormone during sleep
What five theories explain our need for sleep?
(1) sleep has survival value; (2) sleep helps us restore and repair brain tissue; (3) during sleep we consolidate
memory traces; (4) sleep fuels creativity; (5) sleep plays a role in the growth process
How does sleep loss affect us, and what are the major sleep disorders?
• Slow wave sleep, which occurs mostly in the first half of a night’s sleep, produces the human growth
hormone necessary for muscle development. REM sleep and NREM-2 sleep, which occur mostly in the final
hours of a long night’s sleep, help strengthen the neural connections that build enduring memories,
including the “muscle memories” learned while practicing tennis or shooting baskets.
• Optimal exercise time is late afternoon or early evening – body’s natural cooling is most efficient; early
morning workouts rob you of sleep; late night workouts disrupts falling asleep
• Sleep loss is a predictor of depression – 5 hrs or fewer of sleep a night 71% higher risk of depression than
peers who slept 8 or more hours
• REM sleep’s processing of emotional experiences helps protect against depression
• Sleep deprivation = difficulty studying, diminished productivity, tendency to make mistakes, irritability,
• Sleep loss
o makes you fatter; increasing ghrelin (hunger-arousing hormone) and decreasing leptin (hunger-
suppressing partner) and increasing cortisol (stress hormone the stimulates body to make fat)
o suppresses immune cells
o slows reactions, increases errors
• Effects of sleep deprivation in the body
o Brain – diminished attentional focus and memory consolidation, and increased risk of depression
o Immune System – suppression of immune cell production and increased risk of viral infections,
such as colds
o Fat Cells – increased production and greater risk of obesity
o Joints – increased inflammation and arthritis
o Heart – increased risk of high blood pressure
o Stomach – increased hunger-arousing ghrelin and decreased hunger-suppr