Sleep Flashcards
When did sleep research begin?
in 1953, with the discovery of REM sleep by Aserinsky and Kleitman
nonREM sleep is divided into how many stages?
4 1 - light 2- intermediate 3- moderately deep 4- deep
What psychophysiological sleep measures are used to determine sleep stages?
EEG (brain waves), eye movements (EOG) and EMG (muscle tension)
Give characteristics of being awake
responsive, can recall all events
EEG: alpha, 8-12Hz
EOG: eye movement normal
EMG: muscle tension normal
Give characteristics of stage 1 sleep
mind drifting, easy to wake, memory consolidation ceases
EEG: beta and theta waves, <50% alpha, complexes and sleep spindles present
EOG: slower eye movements
reduced EMG
Give characteristics of stage 2 sleep
mind drifting, more difficult to awaken
EEG: slightly increased brain activity
EOG: very little eye movement
EMG: reduced EMG
Give characteristics of sleep stages 3 and 4
mind is fairly blank, very difficult to awaken
EEG: delta waves present, if delta waves showing 20-50% stage 3, >50% stage 4
EOG: absolutely steady
EMG: relatively low
Give characteristics of REM sleep
vivid dreams, emotional arousal, can awake feeling alert, occasional rapid eye movements
EEG: beta, saw-tooth waves
EOG: rapid conjugate eye movements
EMG: further drop off
How many REM periods are in a typical sleep cycle?
approximately 5 - first one is short. 90 minute cycles. Awakenings are a normal part of the sleep period
Sleep mentation is…
the reporting of ongoing mental activity after an awakening from sleep. most remembered in REM, quality of report based on sleep stage.
Seems not to be consolidated in memory, dreaming only occured if awoken during REM
How does age effect sleep?
Steady decline of stage 3 and 4 from childhood
Doesn’t impact people’s lives
Sleep need declines with age (about 1.5 hours between 20 and 70)
What is the homeostatic sleep mechanism?
The system requires a certain amount of sleep - not necessarily 8 hours per night
A person’s sleep drive increases during waking hours and decreases during sleeping hours
What does a circadian rhythm mean?
1 peak and 1 trough in roughly 24 hours, lots of physiological, hormonal, biochemical and behavioural measures are on circadian rhythm
What did the Dawson and Reid study on fatigue, alcohol and performance impairment find? (1997)
Across the day, performance tends to increase
Later in the day, performance begins to drop at about 17 hours of wakefulness and approaches the .05 level
After 23 hours of wakefulness, performance equal to .06 level
What maintains circadian rhythms?
The body clock, located in the hypothalamus called the Supra-chiasmatic nucleus (SCN)
Describe the SCN
- receives visual input from eyes and biochemical input from blood stream
When can extreme eveningness become an issue?
When the circadian phase of evening types conflicts with conventional work demands e.g. 8-9am starts, sleep onset insomnia can develop
Sleep onset insomnia can produce what symptoms?
loss of sleep, daytime tiredness, fatigue and distress
How can we re-time the body clock?
With light: bright light presented in late evening (Tmin) will tend to delay circadian rhythms, bright light presented just after Tmin will push the body clock earlier
What is insomnia?
Sleep onset insomnia, sleep maintenance insomnia, early morning awakening insomnia are three common types of insomnia
What are some problems associated with hypnotic drugs/pharmacotherapy?
effect diminishes with time
sleep deteriorates badly after ceasing the drug
What is CBT?
Cognitive Behavioural Therapy
CBTi is CBT specifically related to insomnia
What are some of the daytime impairments of insomnia caused by?
hyper-arousal from worry, frustration, and triggering the threat response system (SNS)
What does CBT aim to do?
identify and ameliorate the maladapative beliefs about sleep and reduce chronic hyper-arousal
Explain bedtime (sleep) restriction therapy
restricting the amount of time people are lying awake which is a source of frustration and anxiety
The aim is to build up sleep pressure during a restricted bedtime so sleep comes easier when in bed
Explain stimulus control therapy
Essentially - don’t go to bed until you’re very sleepy
If you’re not asleep within 15 minutes - get out of bed and do something until sleepy
Have a fixed wake up time regardless of night’s sleep
What are some sleep conducive behaviours that contribute to positive ‘sleep hygiene’?
- restrict bedroom environment for sleep and sex
- don’t have a fixed bedtime/spend too long in bed
- reduce drugs like caffeine, alcohol, nicotine
- comfortable, quiet and dark bedroom
- deal with worries before bed
What are some helpful relaxation strategies that can help people fall asleep?
meditation, mindfulness, progressive muscle relaxation
What are the steps for general insomnia treatment?
- assess insomnia type
- daytime functioning assessed
- factors causing insomnia determined
- appropriate CBT treatments initiated
- management transferred to patient
What is a nap?
No standardised defintion
- a ‘short sleep’ which is distinct from the normal sleep episode
- any sleep period <50% of average nocturnal sleep period
- anytime during the day during which you may doze or sleep
How common is napping in Australia?
50% of people nap at least once per week
20% of people nap 4+ times per week
Rate of napping a lot higher in countries like Mexico and Nigeria
Where is the greatest proportion of frequent nappers?
Greatest in countries closer to the equator, also known as ‘siesta cultures’
What are siesta cultures?
- lifestyles incorporate ‘quiet time’ in the early afternoon
- Mediterranean region and Central America
- noon/early afternoon is most common time when naps are taken, due to natural dip in alertness (post-lunch dip)
Why do people nap? 3 main types
- replacement napping to catch up on lost sleep
- prophylactic napping in anticipation of sleep loss
- Appetitive napping when you just nap because
What is EDS?
Excessive Daytime Sleepiness
- 10% of population affected (shift workers, sleep disorders)
- if someone scores >10 on the ESS (Epworth Sleepiness Scale), they are experiencing EDS
What are the three processes in the Three-Process Model of Alertness?
- The Homeostatic Process (process S)
- Process W (sleep intertia)
- Circadian process (Process C)
Explain the Homeostatic process
- sleepiness increases at a steady rate from morning awakening throughout the day
- once asleep, sleepiness decreases/alertness increases
Explain Process W (sleep intertia)
- period of decreased alertness experienced immediately after waking
- when you wake up from a long nap and you feel like shit
Explain the circadian process
- internal process affects levels of alertness across the 24hr day
- alertness is coupled with core temperature rhythm
What are the factors that influence the recuperative value of a nap?
- duration
- circadian placement
- prior wake time
- napping experience
How does the circadian placement affect the nap?
- naps taken during post-lunch dip have greatest recuperative value (around 2pm)
- naps taken during the circadian nadir are least recuperative (around 4-5am)
How does prior wake time affect the nap?
- naps are least beneficial after long periods of wakefulness (>18hrs)
What was found during Carskadon’s summer sleep camps?
- sleep quantity consistently 9.25 hrs
- REM sleep stable over time
- 40% decline in deep sleep
What is one effect of <8hrs sleep on adolescents?
adolescents that get less 8 hours of sleep show a poorer working memory performance
When do people experience a decline in slow wave sleep?
around 10-12 years of age
possible explanation of kids ‘growing out’ of sleepwalking/night terrors
What is meant by chronotype?
The determination between morningness and eveningness
What are some environmental influences for adolescents?
- homework
- part-time work
- extra curricular activities
- social (online) activities
- personal activities
These can all contribute to reduced sleep
What is the major factor affecting the sleep of adolescents?
Biological factors account for over 75% of adolescent sleep
Is less sleep on school nights a problem?
some yes and some no
- some studies show lower sleep quantity lowers grades due to compromised learning abilities
- sleep quality a significant player
Is there a link between sleep and mood/suicide?
Greater the sleep disturbance/worse mood
Greater the sleep disturbance/ greater suicide ideation
What is RNT?
Repetitive negative thinking that incorporates ruminating and worrying
What is DSWPD?
Delayed Sleep Wake-Phase Disorder
What are the major points on DSWPD?
- significant delay in major sleep episode
- symptoms present for 3 mths
- when people can choose sleep schedule, sleep improves
What is meant by the term ‘physical activity’?
PA includes all daily activities - all activities that include bodily movement
Exercise is a sub-category of PA - repetitive, underlying goal
Fitness - physiological attribute
What is meant by acute exercise?
A single bout of exercise, effects occur immediately after e.g. increased HR
What is meant by chronic exercise?
habitual exercise. Effects occur as a result of regular exercise e.g. resting HR decrease
What are the 3 most popular hypotheses concerning physical activity assisting sleep?
- thermogenic effect
- circadian phase-shifting effects
- antidepressant and anxyiolytic effects
Explain the thermogenic effect
Trying to rise your core temperature in order to increase the capacity for temperature fall and melatonin secretion
Recommended to finish exercise 2-3 hours before bedtime
Explain the circadian phase-shifting effects
the phase-response curve to exercise suggests it is similar to that of bright light, so exercise can have similar effects on your circadian rhythm to bright light therapy
Explain the antidepressant and anxyiolytic effects
- suggested that main sleep promoting effect of exercise is mediated via reduced anxiety/arousal
- exercise intervention have shown beneficial impact on sleep and depressive symptoms
How much sleep do athletes nee when compared to adults?
adults: 7-8 hrs
athletes: 9-10 hrs
NREM sleep time of restoration and repair, reduced injury and improved health, cognitive benefits
What are some emotional benefits for sleep in athletes?
improves mood and motivation
increases training preparedness and pain tolerance
What could prevent athletes from obtaining sleep?
late night games displace sleep and contribute to poor sleep hygiene
training schedules
travel can cause fatigue and disrupted circadian rhythm
psychological issues e.g. pre-game worries
How does sleep extension improve athlete sleep?
improved concentration task results
improved mood and sleepiness measures
What are some psychological strategies that could assist athlete sleep?
Recording thoughts to deal with negative automatic thoughts
imagery
progressive muscle relaxation
