Exam 2 - sleep Flashcards
Define consiousness
our awareness of ourselves and ourselves in our environment
why is sleep not the same as being unconscious?
1) Brain remains active when asleep
2) Brain processes internal info while asleep (don’t wet the bed)
3) Brain processes external info while asleep (why we don’t roll off the bed)
4) Can be awakened from sleep easily
Why do we need sleep?
We don’t know, but we know you’ll die without it
3 theories for why we need sleep
1) Evolutionary perspective; sleep protects us from the dark/predators
- Lions are at the top of the food chain; can afford to sleep a lot
- Gazelles are common prey; sleep standing up
2) sleep restores body tissue; brain reorganizes and repairs itself/consolidates memories
3) sleep allows us to grow; pituitary gland releases growth hormone; kids need more sleep than adults/elderly
How much sleep do we need?
There’s genetic variability in the need for sleep (mean is 8 consecutive hrs); most will sleep ~9 hrs w/o clocks.
How do our bodies track sleep debt?
They track slow wave and REM sleep for 2 weeks; we need to pay it back (body changes amt of SWS and REM depending on our debt in each)
How is sleep time associated with life span?
People who sleep 7-8 hrs tend to live longer than those tho sleep more or less; people who sleep more often have sleep disorders –> lower quality sleep (not restorative sleep)
How do we know naps are natural/don’t equate to laziness?
people isolated from clocks/daylight slept in two periods
What are 10-20 min naps good for?
“power nap”; boost natural energy; limits you to non-REM sleep –> less groggy when you get up
What are 30 min naps good for?
Not much – can cause sleep inertia/groggy feeling after waking; no apparent restorative benefits
What are 60 min naps good for?
remembering facts, faces, and names; includes slow wave sleep; some grogginess after waking
What are 90 min naps good for?
A full cycle of sleep; light and deep stages including REM; improves emotional and procedural memory; avoids sleep inertia
conditions for melatonin production
pineal gland produces melatonin in complete darkness
what does bright light do to melatonin/our circadian rhythm
inhibits melatonin –> resets our biological clock
How do seasons affect our mood?
not enough sun in winter to shut of melatonin production; we feel sleepy –> seasonal affective disorder
what’s light therapy used for?
bright lights (10,000 lx) shut off melatonin production –> makes us feel more awake
why do we have morning and evening people?
preference for dif times of day is thought to depends on natural variations in circadian rhythms, body temp, and endocrine activity
how was morningness / eveningness tested?
people were kept isolated from clocks and windows (temporal isolation); circadian rhythms ranged from 16-50 hours; short circadian rhythm –> body temp and alertness peak earlier in the day (morning ppl); long circadian rhythm –> body temp and alertness peak later in the day (evening ppl)
heuristics
mental shortcuts; help our brain conserve energy since we have selective attention –> becomes problematic when the shortcuts are stereotypes
what’s the relationship between circadian rhythm and use of mental shortcuts?
you’re less likely to stereotype during your preferred time of day
3 ways of measuring sleep stages
brain waves (EEGs) used for differentiating between non REM stages (N1-N3), eye movements (EOGs), muscle tone (EMGs); the second two are used for differentiating REM sleep
how/why do we become paralyzed during REM sleep?
brain secretes acetylcholine so we don’t act our our dreams and get hurt
how is REM sleep characterized?
smaller brain waves, very low muscle tone, rapid eye movement
How long is a sleep cycle? What are the 4 sleep stages?
90 min; N1, N2, N3, REM
What are the two brain waves when we are awake?
beta: wakefulness (high freq, low amplitude, inconsistent pattern)
alpha: relaxation/right before falling asleep (lower freq, greater amplitude, synchronous)
N1 sleep stage
- 5 min
- transition btwn sleep/wake
- vivid images/hallucinations
- feeling of falling/floating/jerking
- theta waves: low freq, high amplitude, more synchronous than alpha
N2 sleep stage
- 20 min
- wake fairly easily but def asleep
- sleep talking (can happen in other stages too)
- bursts of rapid brain activity: spindles (sudden inc in wave freq) and K complexes (sudeen inc in amplitude)
N3 sleep stage
- 60 min
- delta waves: lowest freq, highest amplitude waves
- deep sleep; most unlike awake
- parasomnias: sleep walking/talking