1
Q
What is the restorative theory of sleep?
A
- rest, recuperation
- repair effects of daily wear & tear
- physiological processes restored
- growth hormone released from pituitary: increased cellular division & RNA synthesis
- REM: protein synthesis, increases after learning
- N3 taxed in learning
2
Q
What is the memory consolidation & learning theory of sleep?
A
- consolidation & facilitation of long-term memory
- brain rehearses newly learned info in N3
- declarative/explicit memory = N3 needed
- nondeclarative/implicit memory = REM needed
3
Q
What is declarative/explicit memory?
A
- conscious recall
- semantic (concepts, facts, landmarks) + episodic (experiences, events)
4
Q
What is nondeclarative/implicit memory?
A
- unconscious recall
- procedures, how to’s, motor skills, habits (throwing a ball, learn to drive, recognise faces)
5
Q
What is the adaptive, survival theory of sleep?
A
Sleep patterns due to:
- predator or prey
- when can see optimally
- caloric use:
- sleep = less calories, less food
- awake when food most available
- environment:
- prevent drowning, sinking, danger
- cerebral hemispheres “take turns”
- move to warmth/cold
- safe, preferred sleeping location
- integrated into annual cycles: hibernation, reproduction
6
Q
What is the energy conservation theory of sleep?
A
small animals: high metabolic rate - sleep longer with shorter NREM-REM cycles
larger animals: slower metabolic rate - sleep less, longer NREM-REM cycles
7
Q
What is sleep like in mammals, birds, reptiles, amphibians, fish & invertebrates?
A
- > 90 species of mammals studied
- closer to humans = more similarities
- all reptiles and birds exhibit N3 & REM but species dependent
8
Q
What is a sleep feature in birds?
A
less REM than mammals, except predator birds
9
Q
What is a sleep feature in owls, moles & opossums?
A
no eye movements
10
Q
What is a sleep feature in dogs, wolves, rabbits & birds?
A
not complete REM paralysis, much eye movements
- phasic eye movement
11
Q
What is a sleep feature in reptiles, tortoises & turtles?
A
high amplitude spikes during sleep
- is it sleep or cold blooded torpor (physical & mental inactivity)?
12
Q
What is sleep like in sea dwelling or migratory animals?
A
- cannot “settle” to sleep, surface breathing, flying long distances
- bottlenose dolphins, porpoises, pigeons, mallard ducks
- asynchronous brain sleeping
- large sea mammals: hold breath and sleep for 30mins, wake to surface & return down
13
Q
What is asynchronous brain sleeping?
A
- one cerebral hemisphere at at a time
- half-brain in N2-N3, while other awake with opp. eye open; one hour each side
14
Q
What is sleep like in bears, caterpillars & frogs?
A
hibernation:
- extreme lowering of body temp, metabolic rate, respiration, with short periodic bouts of rise over several weeks
- no/little recordable EEG
hibernation complete:
- sleep for extended period with increase in N3
15
Q
What is sleep like in fruit fly, marine snail, scorpions, cockroaches & jellyfish?
A
quiescence & activity
16
Q
What is sleep like in infants?
A
- newborn brain immature to produce adult EEG wave patterns
- AS, QS, IS
- healthy newborn: 16-18hrs, >50% in AS
- late term or premature: >75-80% in AS
- enter AS right after falling asleep
- distribution of sleep-wake numerous in nychthemeron
- QS & AS alternate in 50min cycles, increasing in time till 5mths old
- AS = REM at 3mths; QS = N3 at 6mths
17
Q
What is active sleep (AS)?
A
low-voltage, irregular EEG, eye movements, low-high EMG, no motor paralysis; first smile
18
Q
What is quiet sleep (QS)?
A
EEG similar to adult N3, no eye movement, mid-lower EMG, absence of body movements
19
Q
What is intermediate sleep (IS)?
A
mixture of quiet and active
20
Q
What is a nychthemeron?
A
period of 24 consecutive hours
21
Q
What is sleep like in early childhood?
A
- 2-3mths: able to sleep thru night, w/ daytime naps
- 3mths: 40-50% in REM
- 5mths: at least 50% of infants sleep when parents sleep
- 8mths: 33% in REM, sleep 13-14hrs
- between 1-2 years: REM stabilizes at 25%, same as young adult
- 3-5 yrs: sleep 10-13 hrs & daytime napping ceases
22
Q
What is the theory for early childhood sleep?
A
REM important to neural/nervous system maturation; needs stimulation
23
Q
What is sleep like in children?
A
- NREM-REM cycle: 60mins
- enter N3 quickly, stay for 1hr, then arousal-sleep EEG, skip first REM
- position changes
- first REM 10-20mins, w/ subsequent periods 20-25mins
- by 10yrs: cycles resemble adults, but sleep 10hrs
- pre-teen (12-13yrs): fall asleep quickly, v. deep N3, v. difficult to wake
24
Q
What is sleep like in adolescence?
A
- need 9+hrs per nycthemeron
- obtain 6-8hrs (+ sleep in, weekends): signs of sleep debt & deprivation
- 25% in REM
- circadian phase delay to later sleep hours
- vs. school times & learning expectations
25
What is sleep like in adults?
- fatal familial insomnia, death in 12-18mths
- average 7hrs, standard deviation of 1 hr
- 2/3 of population: 6.5-8.5hrs
- 16% of pop. 8.5+hrs, 16% of pop. <6.5 hrs
- minority: sleep <5 hrs regularly & healthy
- growing concern: ppl sleeping less
26
What is fatal familial insomnia?
prolonged sleep deprivation, inherited/passed down thru genes
27
What is sleep like in older adults?
- sleepier in day, less impact of sleep debt/deprivation
- difficult sleep onset, sleep less at night & fragmented, but naps
- sleepy in evening, awake in morning
- 48-50yrs: 4-6 hrs, N3 decline
- 50-60yrs: N3 diminish, 5-10% of sleep
- 85-90yrs: N3 disappears
- Alzheimer’s
- REM: some decrease, but maintained into extreme old age
- more REM earlier in night, more N1 sleep
28
What is Alzheimer's?
marked reduction in N3
- theory: deterioration/less growth requirements of brain cells, cognitive abilities
- study results: long term sleep debt could cause Alzheimer's
29
What are the differences between sleep in women & men?
women:
- go to bed earlier, fall asleep sooner, sleep longer
- more awakenings & time awake in each cycle
- “aging-related sleep changes”: 10 yrs later, 2x sleep spindles, slower N3 decline
- older women: longer to fall asleep, poorer quality & nap more
30
What are factors that affect women's sleep?
- menstrual cycle: natural cyclic progesterone increases sleepiness & speeds sleep onset, estrogen increases REM length
- oral contraceptives: increase melatonin levels & body temp, shift into REM quicker
- menstruation: bloating & pain interrupts sleep
31
What is sleep like during pregnancy?
- metabolic changes, discomfort
- 1st trimester: increased sleepiness, disturbed sleep, blood volume doubles
- 2nd trimester: “grace period”
- 3rd trimester: more & longer awakenings; N3 declines approaching absence
- following birth: recovery from delivery, irregular sleep schedule, breastfeeding, postpartum depression
- 6mths to 1yr to recover most aspects of sleep, sleep efficiency remains low & number of awakenings high into childhood
32
What is sleep like during menopause?
- production of progesterone & estrogen decline, cease
- 40-75% of women complain of sleep issues
- hot flashes: 1.5-5yrs typical = brief arousals, >100 awakenings
- insomnia & sleep-disordered breathing
- hormone replacement therapy: help w/ some symptoms/sleep time, increase sleep quality
- lasts few years
33
What is phase shifting?
phase advancing/delaying
- advancing: shift biological clock forward to earlier time
- delaying: shift biological clock back to later time
34
What are sleep hour preferences?
1. Morning Type (MT)
2. Evening Type (ET)
3. Neither Type (NT)
- genetic disposition, developmental/established habits
- teens become ET, gradually NT, MT characteristics seen by middle age
- questionnaire (Horne and Ostberg): time of day you rise, prefer to rise, feel your best, had to sleep at different times
35
What are the characteristics of MT?
- fall asleep more easily, better moods
- wake more during sleep
- more women tend to be MTs than men
36
What are the characteristics of ET?
- feel more alert & perform better later in day/night
- irregular bedtime habits: higher propensity for insomnia
- experience less jet-lag
- tolerate shift work better
37
What is the biological clock - circadian rhythm?
- “clock-dependent alerting”
- clock genes: Period (per), Timeless (Tim), circadian locomotor output cycles kaput (CLOCK)
- variability influences differences in circadian rhythms
- thousands of genes expressed at once in most tissues & organs regulate cellular function
- vs. stimulation alerting: transitory, once removed will fall asleep
- one peak/strong alerting mid-morning & one mid-late afternoon
- biological clock ensures small sleep debt cannot overwhelm us
38
What is clock-dependent alerting?
physiological process that maintains & consolidates daytime wakefulness
39
What is hypocretin/orexin?
neuropeptide that regulates arousal, helps sustain alertness
| - narcolepsy = orexin deficiency
40
What is sleep homeostasis?
- sleep time reduced, tendency to fall asleep when awake increases
- "extra" sleep obtained, tendency to fall asleep while awake decreases
- ability to stay awake influenced by interaction of clock-dependent alerting & homeostatic sleep drive
- best sleep: timing of biological clock & wake-sleep schedule in synchrony
41
What is sleep need?
“individual requirement of nightly amount of sleep that results in consistent optimal daytime alertness”
42
What is sleep tendency?
strength of inclination/impulse to fall asleep
43
What is sleep latency?
time it takes from bedtime to sleep onset (MSLT)
increase/strong sleep tendency = short/decreased sleep latency
greater accumulated sleep loss = stronger sleep tendency
44
What is the Multiple Sleep Latency Test (MSLT)?
- objective test to measure strength of daytime sleep tendency
- average time to fall asleep during day, if trying to do so in calm, quiet, monotonous environment, w/ no other distractions or disturbances
- 5 measurements: 9, 11am, 1, 3, 5pm
- each nap opportunity: 20 mins
- measure over 7-8 days:
- no substantial change = sleep obtained is amount needed
- daily mins increases = amount of sleep obtained increasing, closer to sleep need
- daily mins decreases = need more sleep than obtaining
45
What is the Maintenance of Wakefulness Test (MWT)?
- average time to sleep, if resisting sleep
- reclined in calm, quiet, monotonous, dark room
- 20-40mins, in 2hr intervals
- used by transportation as measure of post surgical/CPAP use
46
What are the consequences of habitual sleep deprivation? (p, acmecp, u)
progressive decline in:
- alertness & ability to maintain focus & attention
- cognitive performance
- mood
- energy & motivation
- control, coordination & impulsiveness
- pain
- underlying variable: strength of tendency of brain to sleep
47
What is the biological clock?
consists of controls & timing mechanisms that maintain daily 24hr oscillations
- interaction based on transcription-translation feedback loops of "clock genes" & their protein products
48
What is the opponent process model?
interaction of sleep homeostasis & clock-dependent alerting to produce sleep/wakefulness cycle
- correct timing of clock-dependent alerting
- avoiding accumulation of overly large sleep debt
49
What are the principles of optimal alertness?
- not the result of absent/v. low sleep debt, requires stimulation from clock/external sensory input or both
- napping at onset of midday dip in daytime alertness
50
What is sleepiness?
- 3 levels of alertness:
1. energetic, motivated, active, peak alertness
2. tired, lethargic, unmotivated
3. drowsy, sleepy
- pleasant or unpleasant: if permitted to sleep & where
- difficulty communicating sleepiness: children under 9 yrs old + stigma w/ terms
- can't judge arousal states well
- underestimate daily & long term impact of sleepiness
51
What is sleep debt?
accumulated amount of sleep lost than daily need
larger debt:
- stronger drive & tendency, short latency
- cognitive impairment, affective impact
- carry large debt: cannot obtain full "payback"
- obtain as much as possible one night
- continue to increase sleep subsequent nights or nap
52
What is the twilight zone of sleepiness?
- more than 50+ hrs sleep deprivation
| - MSLT scores: 5 mins or less
53
What is the history of sleep deprivation?
Patrick & Gilbert (1896): 90 hrs
- lowered temp, slowed reaction time, memory + sensory decline
Randy Gardner (1965): 17 yr old, Guiness World Record 260 hrs
- fluctuating symptoms: blurred vision, memory decline, irritability, hallucinations, unable to sleep
- 4th day: EEG altered, "no longer awake"
- after: no adverse effects
54
What are findings from animal studies on sleep deprivation?
Rechtschaffen (1980’s) rat on rotating table, above water
- stop grooming, skin lesions
- lose weight despite increase in food intake, body temp declines, reduced thyroxin levels, large cortisol release
- lymph nodes fill with bacteria from intestine, immune system dysfunction, die within 2-3 weeks
55
What are factors that lead to sleep deprivation?
- use of screens
- “caffeine culture”: 8-14hrs to excretion
- “fit more in, get it done culture”, 24-hr availability, expectations of immediacy
- work schedules/type
- social events timing, priorities
- stress
- external stimuli
56
What are the physiological effects of sleep deprivation? (1)
- yawning
- slow eyelid closure, itchy eyes
- heart palpitations
- head drop w/ startle response
- tremors, muscle aches
- increased tendon reflexes & muscle spasm
- body temperature drop
- increased sensitivity to pain
57
What are the physiological effects of sleep deprivation? (2)
- decreased resistance to infection:
- decline in immune system
- natural killer cells unable to fight entering antigens & existing bacteria/viruses
- partial/total loss of effect of recent vaccinations
- growth hormone reduced
- longer recovery after exercise
- increase in cortisol release
58
What are the physiological effects of sleep deprivation? (3)
- decrease in leptin, increase in ghrelin & insulin secretion = more fat storage
- chronic sleep dep: high blood pressure, diabetes, obesity
- brain: more/varied brain regions “help out” in complex tasks
- caffeine helps arousal of brain, but functions dependent on prefrontal cortex remain impaired
- micro-sleeping
- REM rebound: REM pressure, takes longer than N3 rebound
59
What is micro-sleeping?
brief NREM sleep, complete inattention but denial of sleeping
60
What is REM rebound?
higher REM % when return to sleep
| - antidepressants eliminate REM w/o effects
61
What is REM pressure?
pressure for REM to rebound as fast as possible, missing REM stage
62
What are the psychological effects of sleep deprivation? (1)
- psychomotor, cognitive & perceptual effects
- loss of alertness, reaction time
- lapse in concentration
- impaired ability on complex tasks
- innovation, creativity & flexibility decreases
- simple, well-practiced, externally motivated, less than 10 min less effected
- decrease in ST memory
- loss of verbal fluency
63
What are the psychological effects of sleep deprivation? (2)
- hesitancy in decision making/errors of inattention
- mistakes more frequent: if competing distractions & sorting involved
- inability to plan ahead
- risk taking behaviour, impulsivity increases
- increase chance of injury
- pessimism, impatience, irritability, anger, controlling negative mood, more susceptible to arguments
64
What are the psychological effects of sleep deprivation? (3)
- inappropriate behaviours, emotional outbursts
- unable to judge space/volume
- role clarity declines, personal focus increases
- unable to be empathetic
- more susceptible to suggestions
- disorientation, confusion
- mistrustful, paranoia, hallucinations
65
What are ways to stay awake during sleep deprivation?
- masking: extraneous influences override sleep propensity, temporary
- alcohol worsens sleepiness
- splashing cold water, fast moving air, loud music, dance around: temporarily reduce effects
- caffeine followed by nap can assist for up to 3 hrs
66
What are the societal effects of sleep deprivation? (1)
- sport performance: “home turf advantage” & speed, shot accuracy decreased
- parental information on sleep training & consequences of sleep deprivation limited
- school aged children misdiagnosed w/ behaviour disorders
- university students: depart for vacation
- misdiagnoses, medical errors
- severe, fatal motor vehicle injuries
67
What are the societal effects of sleep deprivation? (2)
- driving after 24hr sleep deprivation = 0.10 blood alcohol level (legally drunk)
- firefighters, police, military personnel
- physicians, nurses, paramedics, anesthesiologists, medivac
- taxi drivers, bus drivers, air traffic control & air mechanics
- emergency utility workers
- oil tankers, nuclear reactor management
68
What are things we can do to prevent sleep deprivation?
- close gap b/w medical scientific sleep knowledge & application: prevent deleterious effects/large catastrophes
- respect sleep, take responsibility for healthy sleep, restructure priorities, learn to manage it
- if sleep educated: talk w/ family & friends
- sleep specialists provide education for all levels
- reach leaders in academia, government + health and safety industries
69
What are consequences of sleep debt?
- impairs: mood, sense of well-being, energy, intellectual function, performance & attentiveness
- affects classroom behaviour & mood in children
- associated w/ suicide ideation & suicidal behaviour
- imbalances in brain regions w/ sleep disturbances associated w/ risk-taking behaviour
70
What is the optimal sleep/wake schedule?
1. sleep debt reduced to as low as possible
| 2. maintain bedtime schedule that fulfills sleep requirement
71
What is full alertness?
absence of sleepiness and/or tiredness & optimisation of energy, motivation & intellectual capacity
72
What is the Stanford Sleepiness Scale (SSS)?
- measures subjective sleepiness
- statements that describe range of feeling states associated w/ 7 levels of sleepiness/alertness
- choose one that best describes, rating every hour
73
What is the Epworth Sleepiness Scale?
- obstructive sleep apnea & narcolepsy
| - max = 24, excessive sleepiness = < 10
74
What are other causes of tiredness?
- decreased stimulation
| - physical exertion
75
What are the waking functions affected by sleep?
- task performance impaired
- ability to do complex tasks impaired
- mood negatively affected
- motivation decreases: apathy
- self-control & impulsiveness decreases
- high-level cognitive function impaired, negatively affected: memory & creativity
- lapses & micro-sleeps increase
- psychomotor vigilance task: slower reaction time
- brain activity: function of specific brain areas diminish
76
What is apathy?
tendency to sit & do nothing
77
What is the psychomotor vigilance task?
- 10 mins, subject watches small screen for flashes of light
| - press button quickly in reponse to each flash
78
What is “home turf advantage”?
team playing at time of peak circadian alerting
79
What is a sleep crisis?
- sudden, unexpected need to stay up all night for critical task/emergency
- “all nighter”
- worsening sleep disorder to point of serious illness/high risk to safety
80
What is an "all nighter"?
self-chosen willingness to stay awake for full nycthemeron
81
How can we cope with sleep crises?
- knowledge, preparation, use of tools
- know sleep need & bio rhythms, best time for perform
- biological clock at lowest ebb in middle of night: more prone to distraction, ST memory recall issues, slow RT, mistakes & cognitive issues
- attempt to plan ahead
- lower sleep debt previous to crises
- avoid alcohol, fatty/heavy foods
82
What are the types of naps?
- emergency nap
- preventative: prepare for sleep loss
- habitual
- selective, strategic: for performance
83
What are the best napping conditions & can napping do?
- time: 10-90mins, less than 4 hrs
- diurnal schedule: before 3-4pm
- improve objective performance
84
What is jet lag?
- mismatch of internal circadian clock w/ external local clock b/c of rapid travel
- timing offset: hunger, fatigue/energy, activities
- feel ill, flu-like: nausea, GI (gas intestinal) upset/constipation/diarrhea, muscle soreness, headaches
- distracted, disorientation, moody
- 1/3 not affected at all, others mild to debilitating
85
What makes jet lag worse?
- travelling east
- greater time zones
- older age
86
How does direction difference affect jet lag?
“east is the beast, west is the best”
- travelling east:
- body’s circadian rhythm behind local time
- problems falling asleep at local bedtime
- difficult to wake up in the morning
- v. few issues travelling north or south
87
What are ways to adjust to jet lag? (1)
- adjust body temp, hormonal rhythms
- complete recovery:
- to the west: 1 day per time zone
- to the east: 1.5 days per time zone
- rapid changes the first few days, tapering off
- try to “live in the time zone” the arrival clock before you leave, or make small adjustments 1 week to 1-2 days before
- sleeping pill
88
What are ways to adjust to jet lag ? (2)
- set/reset if lengthy stay
- attempt to “be local” when you arrive
- exposure to sunlight, bright light
- nap: only if necessary, 30min max, drop in clock dependent alerting
- melatonin:
- flying to later time = take earlier
- flying to earlier time = take late in the day
89
What are the types of shift work?
1. day: 7/8am - 4/5pm
2. evening/swing: 4pm - midnight, 6pm - 1am
3. graveyard: 11/12pm - 6/8am
4. split: 5/6am - 10am & 7 - 10/11pm
90
What are the challenges with shift work?
- shifts change regularly
- common: one week on/off
- daytime to graveyard phase shift most difficult
- more difficult for MT than ET, people who have a large sleep need, people over 50yrs old, or with chronic illness or sleep disorders
- tend to sleep less & less efficient if attempting to do so during the day
- difficult to live w/ others on diurnal schedule will switch during days off
91
What are the features of shift workers?
- less job satisfaction, more absent
- 50% higher than average MVA when driving home
- more negative moods, emotional issues, report social isolation family issues & +57% divorce rates
- higher reports of stomach & GI problems, CV disease, and cancer, higher mortality rates
92
What are ways to cope with shift work?
- consistent shifts: stay on day/night for 3+ weeks
- slow graduating clockwise shifts: day to evening, to night to day
- more light during shift & very dark situations for sleeping during the day
93
What is the goal of sleep hygiene?
- continuous, quality sleep, for optimal daytime alertness
| - make sleep a priority over other choices
94
What is the best sleep environment?
- bedroom: associate room only w/ sleeping & sexuality
- quiet: earplugs, reduce unpredictable noise, music/TV, voices
- dark: window & eye coverings, avoid screens for reading, light emitting in room
- comfortable, clean bed
- control temp, air circulation & humidity: cooler w/ warm blankets/clothing
95
What are physical sleep practices?
- consistent sleep schedule: preparation, time of day/night; including weekends
- avoid working out/exercise 2-3hrs before, depending on type & time of day
- stay in bed, try to sleep when drowsy not if wide awake
96
What are psychological sleep practices?
- adequate time to unwind, calming pre-sleep routine before
- avoid looking at clock
- mental listing: paper, pen beside bed/do so before heading to bed/bedroom
- worry/anxious: self-talk, permission to sleep to deal w/ issue next day
97
How do substances affect sleep?
- avoid = caffeine post 4pm, alcohol, spicy, heavy/fatty or large meals, large amounts of fluid
- if hungry, warm drink; tryptophan
- be aware of when smoking/reduce: awake if nicotine levels reduce during night
- read medication inserts carefully, side effects & synergistic interactions
- valerian, chamomile, lemon balm, lavender, kava, cherry juice: no effect compared to placebo
98
How does THC affect sleep?
- low dose (4-20mg) = sedative, reduced REM, N3 increase with initial use
- high dose (50-210mg) = psychoactive effect, REM + N3 decrease
- stop use = REM rebound, increased sleep latency, reduced sleep efficiency
99
How does pain affect sleep?
sleep onset/latency affected, less N3, more awakenings
100
How does illness affect sleep?
bacterial, fungal, viral infections: increase sleepiness
- increase in cytokines -> N3 time & amount of delta waves produced 1-2 days following infection & then decrease below normal levels
- REM sleep decreased during infection
101
How does music affect sleep?
- soft melodic: enhance sleep onset
| - unpredictable stimulating/annoying: affects onset & maintenance of sleep
102
How does weather affect sleep?
- weather extremes/climate change = need adaptation to changes
- lunar phase, solar disturbances, barometric pressure
103
How does driving affect sleep & how to prevent drowsiness?
- sleep debt causes drowsiness
- plan ahead: reduce sleep debt before trip + leave when circadian clock has you more alert
- several drivers
- if you feel drowsy, STOP DRIVING
- nap
- coffee after nap
104
What is "over-sleeping"?
sleeping for more than you believe you should/need
105
What are the effects of sleeping too much?
- extra sleep: low efficiency, very little N3
- feeling groggy/lethargic/“thick headed”, sore muscles, emotional low, irritability
- irrational, impulsive, socially embarrassing, no memory of activity
- typically 10-15min post long sleep/nap, up to an hour
106
What is sleep inertia?
- lack mobility for extended period
- wake-up when mid-day dip in clock dependent altering
- wake up during N3
- worse w/ sleep dep: sleep debt exists
- less noticeable following gradual morning awakening after full night of normal length & quality of sleep
- cannot “store sleep”: remain awake when enough
PSYC 208
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