Measuring Sleep
Identify the three physiological measures of sleep on the study design.
EEG, EOG, EMG
What proportion of their total sleep do newborn infants spend in REM?
50% / more than half.
Time spent in REM sleep is significantly high because newborns and infants are experiencing rapid brain development.
What is the hormone that initiates sleep and regulates the sleep-wake cycle, and where is it produced?
Melatonin, produced in the pineal gland.
What do DSPS and ASPD stand for?
Delayed Sleep Phase Syndrome.
Advanced Sleep Phase Disorder.
How many hours without sleep did a study find was an equivalent performance level to 0.05% BAC?
17 hours
What does DARE stand for?
Detect, Amplify, and Record the Electrical Activity of
What happens to NREM Stages 2 and 3 for a total sleep episode in adolescence, compared to childhood?
For adolescents NREM sleep show less stage 3 than childhood, whilst time spent in stage 2 increases in adolescents compared to childhood.
Where is the suprachiasmatic nucleus located, and what information does it receive from the eyes?
Located in the hypothalamus and receives information about levels of light.
Name one of the 3 reasons someone might develop a circadian rhythm sleep disorder.
a naturally occurring change or a malfunction of biological mechanisms or processes regulating the sleep–wake cycle
a mismatch between an individual’s sleep–wake cycle and the day–night cycle of their physical environment
a mismatch between an individual’s sleep–wake cycle and the sleep–wake schedule required by their school, work or social schedule.
Describe one A and one B who is partially sleep deprived.
Affective: Sleep deprivation can result in a person feeling irritated or short-tempered and can interfere with emotional regulation and reactivity. Studies have shown that people who are sleep deprived have difficulty recognising emotions in faces and are more likely to argue with others.
Behaviour: refers to a person’s observable actions. When sleep deprived, you may have trouble controlling your behaviour, participate in more risk-taking or impulsive behaviour, take longer to finish tasks, have reduced productivity and work efficiency, be reluctant to get out of bed in the morning or be more accident prone
Sleep inertia (feeling of grogginess) is common after wakening. This can result in slowed reaction times and motor function.
Define altered state of consciousness and provide an example of an induced one.
ASC = state of consciousness that is significantly different from normal waking consciousness or any waking state in terms of level of awareness and experience. Induced = drug/alcohol, meditation, hypnosis.
For a healthy adult, what proportion of their total sleep episode is spent in REM, and, what happens to the duration of REM in each cycle as the sleep episode progresses?
REM total proportion for healthy adult = 20-25% Each REM cycle across the night gets longer in duration, with longest one being before final awakening.
What two biological rhythms do you need to know, and what is an example of each one?
biological rhythms are called circadian and ultradian rhythms. Circadian = sleep-wake cycle over 24 hours, ultradian = sleep cycle (less than 24 hours, repeats throughout the 24 hours), digestion, blood pressure.
What is Bright Light Therapy and how does it work?
Involves timed exposure to intense (but safe) amounts of light (either natural or artificial) in order to reset the sleep-wake cycle to the desired schedule.
Prompts the wake-inducing biological mechanisms involving the circadian rhythm and suprachiasmatic nucleus, and delays the release of melatonin, which promotes wakefulness.
Describe 3 cognitive impacts of sleep deprivation
refers to a person’s mental processing. When sleep deprived, you may experience with these cognitive functioning issues:
• trouble with memory
• decreased alertness
• poor concentration
• impaired problem solving, decision making
• poor judgement
• lack of motivation
• trouble coping with change or stress
• difficulty learning new concepts
• slower thinking
• a shortened attention span.
Compare and describe the difference in what an EEG show in REM sleep and NREM Stage 3.
REM = beta waves, high frequency, low amplitude. NREM Stage 3 = delta waves, low frequency, high amplitude, slow wave sleep.
In older adults, lower levels of sleep tend to be attributed to ill-health and an increase in the prevalence of sleep disorders, as well as the reduced amount of cognitive and physical growth within this age group. Common misconception that sleep needs decline with age.
Blood temp and pressure drop, body movements decrease.
What are the characteristics of ASPD?
Persistent disturbance of the sleep–wake cycle characterised by advance of the major sleep episode to an earlier time compared to desired or conventional sleep times. People with the disorder keep going to bed and waking up too early because of their difficulty or inability to remain awake or asleep until they want to.
Biologically, explain why a teenager may experience sleep deprivation as a result of DSPS.
In adolescence there is a shift in the time release of melatonin from the pineal gland to be 1-2 hours than other age groups, making that sleepiness and sleep onset occurs 1-2 hours later for teenagers. If a teenager needs to wake-up to be aligned with society's clock, and are falling asleep later, they will not get the required 8-10 hours of sleep per night and will be sleep deprived.
Sleep diaries are considered subjective as they rely on the participant to relay the information which may be biased by personal opinion, point of view, judgement etc.
They can keep a record of:
Time when trying to fall asleep
Time when sleep is thought to have occurred
Number, time and length of awakenings
Time of waking up
Time of getting up (as opposed to waking up)
Feelings of well-restedness
Feelings of sleepiness during the day
Things that may affect sleep (e.g. caffeine, naps, medications)
State three differences that would be evident in the hypnogram of an elderly person, compared to an adolescent.
More periods of awakenings during the night for the elderly than the teenager. Overall longer sleep episode for teenager compared to elderly.
If you wake up in the middle of the night and turn the lights on, what would be the changes detected in the body, and how would this impact wakefulness?
Suprachiasmatic receives information about the bright light from the eyes, and sends a neuronal message to the pineal gland to supress/decrease the release of melatonin into the blood stream, resulting in an individual feeling more wakeful.
How is Bright Light Therapy used to treat DSPS, ASPD, and shift work?
Delayed sleep phase disorder: Exposure in early morning to shift phase forward
Advanced sleep phase disorder: Exposure in early evening to shift phase backward
Shift work: Best to avoid light between end of shift and wake time. Use BLT as soon as wake from sleep/before going to work.
Define what a zeitgeber is and explain how two of these can impact sleep hygiene.
Zeitgebers are environmental time cues that are used by the suprachiasmatic nucleus to adjust circadian rhythms to a 24 hour day. Examples, with relevant justification: light (sunlight/blue light/artificial light), alarms, school bells, food, temperature, weekly garbage truck etc - linked to how it changes sleep hygiene.