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
REM sleep stage
- 10 min
- brain waves similar to stage 1 (combo of alpha, beta, and desynchronous; heart rate/breathing inc, eyes twitch)
- beginning of a dream
- brain cortex active; brainstep blocks messages –> can’t move
non declarative memories
gained through experience/practice, not memorization (ex driving)
*consolidated in REM sleep
declarative/explicit memories
memories you can talk about; relationshpis between stimuli and events (ex memory of a landmark)
*consolidated in slow wave sleep (Stages N1-N3)
Order of regression through stages during sleep cycle
N1, N2, N3, N2, REM
N2, N3, N2, REM
N2, REM
N2, REM
*prioritize SWS for first 4 hrs; prioritize REM last 4 hrs (REM periods get longer through the night)
when do we usually remember our dreams?
when we get woken up during REM
relationship between stress and sleep
people stressed during the day sleep avg 1 hour less than normal person
insomnia
10-15% of adults; persistent problems falling/staying asleep
treatments for insomnia
do your best to associate bed with sleep; get up if you can’t fall asleep in 15 min
effect of alcohol on sleep
it’s a somnigen (makes it easy to fall asleep); but we don’t have good quality sleep because our body is trying to fight the somnigen effect of alcohol
narcolepsy
1/2,000 ppl; spontaneously go into REM sleep; usually appears in teen years; caused by absence of neural center that produces neurotransmitter hypocretin; episodes can be triggered by strong emotions
sleep apnea
tongue relaxes into throat; intermittently stop breathing during sleep; brain isn’t getting oxygen –> wakes you up (not enough to realize you’re up); 1/20 ppl; causes CNS to stop functioning; disrupts sleep cycle –> not staying in SWS or REM
treatments for sleep apnea
CPAP machine
symptoms of sleep apnea
waking up thirsty/tired
parasomnias
sleep walking/talking, tooth grinding, night terrors (sitting up, walking, talking, inc heart/breathing); some parasomnias are common in children but not adults; usually happen in deep sleep (N#) but not in REM
REM sleep behavior disorder
type of parasomnia; don’t experience paralysis (atonia) during REM –> act out dreams; onset can be sudden or gradual but usually gets worse with time; people are not aware when doing it; can be awoken easily and remember dream; not related to daytime psychiatric disorder; can be precursor to neuro disorders like parkinson’s
risk factors for developing REM SBD
being male and 50+ yrs old; younger ppl at greater risk if they have narcolepsy, antidepressants, brian tumors; correlation btwn REM SBD and neurodegenerative disorders
What causes alien abduction feeling?
ACETYLCHOLINE is released during REM and makes us paralyzed. MIDDLE EAR VIBRATES during REM and can lead to hearing high pitched sounds. Feels like you’re moving bc REM activates VESTIBULAR SYSTEM and simulates movement while asleep; AMYGDALA (fear center) activated during REM. People hear stories of alien abductions on TV.
In what two stages is sleep paralysis most likely?
hypnagogic (right before sleep) or hypnopompic (right after waking)
Does caffeine resolve sleep deprivation?
NO. It masks feelings of fatigue
Factors that can show how sleep deprived a person is
how is their attention to detail? Do they fall asleep within 5 minutes? Do they have micro blackouts when they blink?
Effects of sleep deprivation
irritability, car accidents, more mistakes, slower reaction times, decreased cognitive function and killer T cells
When should we avoid caffeine?
avoid caffeine for 1 hour after waking; cortisol naturally spikes in this time and drinking caffeine can reduce our body’s natural spike. Cortisol also spikes in the evening.
Blood alcohol equivalents of sleep deprivation
17 hours awake = BAC 0.05
24 hours awake = BAC 0.1
What does “independent debt” mean for SWS and REM?
our bodies track SWS and REM as two different sleep debts; it needs enough of each
what does leptin signal
low leptin = feel like we’re starving
what does ghrelin signal
high ghrelin increases appetite
how does sleep impact metabolism
sleep deprivation decreases leptin (feel like we’re starving) and increases ghrelin (increases appetite)
How are BMI and sleep related
BMI is proportional to sleep loss (low sleep = higher BMI)
how is stress related to weight gain
Weight gain is proportional to stress (esp. around stomach); this is an increase in visceral fat (surrounds our organs), compared to subcutaneous fat (under skin that we can feel/punch)
why is blue light bad?
blocks melatonin production; has a greater effect on shifting our circadian clock than longer wavelengths of light (red light)
How was it proven that blue light hinders our ability to fall asleep?
people who read on screens took longer to fall asleep compared to people that read paper books
how does alcohol make us feel sleepy?
increases GABA and adenosine (blocks wake-promoting cells in basal forebrain)
what does alcohol do to SWS and REM
decreases REM and increases SWS during 1st half of the night; can disrupt sleep and cause waking during second half of the sleep cycle
effect of alcohol on insomniacs
had less disturbances and improved sleep; BUT it should not be used as a sleep aid; it’s a diuretic and can cause you to wake up to go to the bathroom
ways to facilitate sleep
1) consistent bed/wake schedule
2) no screens 1 hr before bed
3) light exercise during day
4) cool, quiet, dark bedroom
5) sun exposure every day
6) restrict bed for sleep/relaxing
7) relax/meditate/bathe before bed (steam cools body)
8) avoid large meals/sugar @ night
9) avoid alc, smoking, caffeine in evening
10) don’t nap after 3pm
how to get up early
1) plan exciting breakfast
2) schedule exciting plans for morning
5 theories for why we dream?
1) psychoanalytic perspective
2) activation synthesis theory
3) neurocognitive theory
4) filing away memories
5) preservation of neural pathways
psychoanalytic perspective
- freud
- dreams = wish fulfillment/royal road to understanding our unconscious (bc it doesn’t get filtered out when we dream)
- manifest content: what a person remembers/sees int heir dream
- latent content: underlying hidden meaning of the manifest content (must be analyzed by psychoanalyst/psychologist)
- used free association and dream analysis to access peoples’ unconscious conflicts that caused their problems (freud traced problems bad to sexual wishes - freudian slips)
difficult to test scientifically
freud’s manifest content : latent content translations
authority figure : parents
small animal : child
water : birth
journeys : death
uniforms/clothes : nakedness
houses : human body
phallic symbols : sexuality
activation-synthesis theory
brain has random activity while we sleep; amygdala activity increases, frontal lobe activity is decreased (we lack logical thinking); dream = brain trying to make sense of this activity; hard to test scientifically
neurocognitive theory
dreams = special kind of thinking/function of cognitive maturation; dreaming/ability to remember them req cognitive maturity ~4 yrs old; contain elements of “what’s on your mind?”
file away memories theory
sorts the day’s experiences and saves some as memories; people seem to remember/improve at new tasks better after sleep; during REM memories are stored/erased/transferred from hippocampus to long term, emotional experiences resolved
developing/preserving neural pathways theory
stimulate brain, develop/preserve neurons; dreaming exercises synapses between brain cells; infants have developing neural pathways which makes them sleep more than adults
