chapter 8

Question 1

partial sleep deprivation

Answer 1

-the experience of achieving inadequate sleep in terms of quantity or quality

• Sleep quantity refers to the duration of sleep, or the number of hours you sleep.
  -Sleep quality refers to how well you sleep, such as whether you were woken up in the night or how deep and restful your sleep is.
  -even though you may be getting enough total hours of sleep for your age, your sleep may be disrupted, resulting in poor-quality sleep.

Question 2

many factors may contribute to sleep deprivation, including:

Answer 2

• consuming caffeine, food, drugs or alcohol
• work or school requirements
• failing to wind down before bed
• stress
• medical conditions
• an uncomfortable sleeping environment
• social influences.

Sleep deprivation can have many negative effects on a person’s affective, behavioural and cognitive functioning

Question 3

affective functioning

Answer 3

-A person’s experience of their emotions

-When sleep-deprived, you may have trouble regulating or controlling your emotions
- You may experience mood swings or emotional outbursts, feel sad or depressed, be more irritable or cry for no
apparent reason

For example, when very sleep-deprived, you may get overly annoyed when your parent asks you to do a regular household chore.

Question 4

behavioural functioning

Answer 4

-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
-be more accident-prone

-Children may show hyperactive behaviour and increased misbehaviour. For example, a child who is sleep deprived may have trouble following rules in class and may show more ‘naughty’ behaviour.

Question 5

cognitive functioning

Answer 5

• a person’s mental processing

when sleep-deprived you may experience 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.

Question 6

comparing sleep deprivation and blood alcohol concentration

Answer 6

-alcohol has detrimental effects on the brain and body
-Research in this area has guided governments and state transport departments to make laws for the blood alcohol concentration (BAC) (the percentage of alcohol in the bloodstream)
allowed when driving cars and other motor vehicles, ensuring safe driving.
-in VIC the legal BAC for driving a car is under 0.05%
- a BAC level above this limit has negative and detrimental effects on a person’s functioning (affective, behavioural and cognitive)
-these negative effects increase as BAC increases

Question 7

sleep deprivation VS BAC

Answer 7

-the effects of 17 hours of sustained wakefulness are equivalent to the effects of a BAC of 0.05%.
-the effects of 24 hours of sustained wakefulness are equivalent to the effects of a BAC of 0.10%
- after sustained wakefulness of 17–19 hours, performance levels are so low that many countries would consider them to be incompatible with safe driving.

-the detrimental effects on cognitive functioning include poorer concentration, attention, decision making and problem-solving ability.
-The effects on affective functioning include poorer emotional regulation, increased irritability and emotional outbursts.

Question 8

overview of circadian rhythm sleep disorders

Answer 8

-Sudden changes to a person’s sleep-wake schedule can cause their circadian rhythm to become out of sync with the external environment.
-This can happen if a person works night shifts or at the beginning or end of daylight saving.
-When a significant misalignment occurs
and a person’s body cannot readjust, it may cause them distress or dysfunction and a circadian rhythm sleep disorder can be diagnosed.

Question 9

circadian rhythm sleep disorders

Answer 9

-a category of sleep disorders in which sleep is disrupted because the circadian rhythm and a person’s sleep-wake schedule are misaligned.

-The misalignment causes excessive
sleepiness, insomnia, distress or impairment of a person’s functioning.
-These disorders may cause a person to be unable to sleep and wake at the appropriate times needed to attend school, go to work or participate in social activities.

Question 10

3 different circadian rhythm sleep disorders

Answer 10

Delayed Sleep Phase Syndrome, Advanced Sleep Phase Disorder and shift work.

Question 11

bright light therapy

Answer 11

-A therapy to treat a sleep disorder in which the person is exposed to a bright light to reset the sleep-wake cycle.

-The strategic exposure to light prompts the wake-inducing biological mechanisms
involving the circadian rhythm and suprachiasmatic nucleus, and delays the release of melatonin, which promotes wakefulness.
-a safe but artificial source of light .e.g. desk lamp

Question 12

delayed sleep phase syndrome (DSPS)

Answer 12

-a circadian rhythm sleep disorder characterised by a delay in the timing of sleep onset and awakening compared with the timing that is desired.

-The delay is usually for two or more hours, with a person falling asleep later than what is required or conventionally accepted.
-This then causes a need to wake up later than required if a person is to achieve an adequate amount of sleep.
-e.g. instead of sleeping 10 p.m. until 6 a.m., a person may sleep from 2 a.m. until 10 a.m.

-The delay in sleep onset contributes to a sleep disorder when a person is unable to achieve their recommended amount of sleep because they need to wake in the morning for work, school or other commitments.
-A person with DSPS usually cannot fall asleep at an earlier, more acceptable time due totheir shifted circadian rhythm.
-In order to be diagnosed with DSPS, a person needs to experience symptoms for more than three months.

Question 13

predisposing risk factors for DSPS (other than age)

Answer 13

-a longer than average circadian period
-an increased sensitivity to light

-increased sensitivity to light in the evening might cause a delayed night-time signal to the suprachiasmatic nucleus, which delays melatonin release by the pineal gland, resulting in fewer signals to the body that it is time to sleep.
-less sensitivity to morning light upon waking up causes a lack of light cues to the suprachiasmatic nucleus to signal a reduction in melatonin release by the pineal gland.

Question 14

DSPS link to improving sleep-wake patterns and reducing symptoms

Answer 14

-people with DSPS who can adjust their lifestyle to suit their particular sleep schedule tend to experience less sleep deprivation and symptoms

REDUCING SYMPTOMS:
-. If that is not possible, they can help shift their circadian rhythm to a more appropriate time by using bright light therapy.
-Exposure to light in the early morning can help reset the sleep–wake cycle by reducing melatonin release earlier in the morning.
-This resetsthe circadian rhythm, prompting the SCN to trigger melatonin release at a more appropriate earlier time of the
evening, and therefore advances
sleepiness.
-This therapy also includes limiting night-time light exposure and gradually going to bed earlier each
night over several weeks.

Question 15

advanced sleep phase disorder (ASPD)

Answer 15

-a circadian rhythm sleep disorder characterised by an advance in the timing of sleep onset and awakening compared to the timing that is desired

-A person may fall asleep usually two or more hours earlier than what is needed or acceptable, resulting in them then experiencing an earlier waking time than is desired.
-e.g. instead of sleeping 10pm-6am, a person may sleep 8pm-4am.
-if a person with ASPD attempts to adhere to a more reasonable, later bedtime, they will continue to have an early wake time due to the shift in their circadian rhythm

Question 16

APSD cont.

Answer 16

-By going to bed early and then waking early, a person is not exposed to the regular evening low light and morning bright light signals, which then perpetuates the advanced circadian rhythm cycle, maintaining the disorder.

Question 17

ASPD symptoms

Answer 17

-Different people experience different symptoms for ASPD but symptoms get more severe when work or social demands require a schedule that does not match the person’s natural sleep–wake cycle.
-sleep onset earlier than normal
-early awakening
-overwhelming sleepiness in the early evening

Question 18

ASPD link to improving sleep-wake patterns
+ strategies to reduce symptoms

Answer 18

-When a person can adjust their daytime commitments to sleep and wake at their own schedule, they tend to have a stable sleep pattern and reduction in symptoms.

STRATEGIES TO REDUCE SYMPTOMS:
- if not people with ASPD can help shift their circadian rhythm to a more appropriate time by using bright light therapy.
-Exposure to light in the early evening results in later melatonin release, and therefore delays sleepiness until a more appropriate later time of the evening.
-This can help reset the sleep–wake cycle to a more conventional timing

Question 19

shift work

Answer 19

-work that regularly takes place outside of normal business hours, particularly at night and the very early morning; can cause a circadian rhythm sleep disorder.
-This can include a consistent night shift or a rotating schedule, in round-the-clock professions such as: health
care, hospitality, factory work, transport and travel.

Question 20

effects of shift work

Answer 20

• Shift work can put a person’s sleep–wake schedule in direct opposition to the regular day–night environmental
  hours, resulting in distress and dysfunction due to excessive sleepiness at work and impaired sleep at home after their shift.
  -e.g. working night shift, sleep may be disrupted during the day due to sunlight, noise of cars, etc. which may result in sleep deprivation and excessive sleepiness while working the following night.

Question 21

shift work cont.

Answer 21

-This disorder affects 5–10% of the population who work during nights, particularly at the middle-aged stage of the life span, in jobs that involve shift work (paramedics, airline
flight crews, bakers, bartenders and police officers)
-Diagnosis depends on how severe the symptoms are and the level of distress experienced by the person

Question 22

consequences of shift work

Answer 22

• poor performance at work, interpersonal problems, increased risk of accidents and poor mental wellbeing, which can even lead to other mental disorders such as depression and substance
  use disorders.
  -there is a link between prolonged shift work and physical health problems such as gastrointestinal disorders, cardiovascular disease, diabetes and cancer.

Question 23

reducing symptoms of shift work

Answer 23

-symptoms reduce when they can spend longer on one shift rotation before changing.
-Where rotating schedules are required, they should ideally shift forward, such as from morning shift, to afternoon shift, to evening shift, to allow a person the best chance to adjust.
-symptoms resolve when a person commits to a typical day-time shift rutine.

Question 24

shift work link to improving sleep-wake patterns
+reducing symptoms

Answer 24

-People with a disorder caused by shift work can also help adjust their circadian rhythm to suit their work schedule by using bright light therapy.
- Exposure to light before an evening
or night-time shift can help delay the release of melatonin, helping a person feel more awake during their shift, and then sleepy when the shift is finished in the morning

Question 25

improving sleep hygiene and adapting to zeitgebers

Answer 25

-Eating a healthy diet, getting regular exercise and achieving an appropriate quality and quantity of sleep (the three pillars of health)
-improving all three components may be beneficial for sustaining physical and mental well-being in people at risk of neuropsychiatric disorders.
-Poor sleep patterns have been consistently linked in a bidirectional way to serious physical health concerns such as: diabetes, weight problems, hypertension, cardiovascular disease
-and mental health concerns, including: depression, bipolar disorder, anxiety disorders and
schizophrenia.

Question 26

sleep hygiene

Answer 26

-the sleep-related behaviours and environmental conditions that are beneficial for sleep
-changes we can make to our bedtime routine to promote
sleep:
* avoid the use of devices and caffeine before bed
* follow a wind-down bedtime routine
* avoid ‘watching the clock’
* minimise light and noise
* ensure a cool temperature
* have comfortable bedding

-If you follow recommendations for good sleep hygiene consistently, you may be more likely to fall asleep faster as well as remain asleep, maximising both sleep quantity and
quality and overall promoting wellbeing.
-Many sleep hygiene practices consider important sleep-related zeitgebers.

Question 27

zeitgebers

Answer 27

-an environmental cue such as light,
temperature and eating patterns that can synchronise and regulate the body’s circadian rhythm.

-These cues have different abilities to
shift a person’s 24-hour sleep–wake cycle, and so can be purposefully used by a person to improve their sleep–wake cycle and therefore their mental wellbeing.

Question 28

1. LIGHT
   daylight:

Answer 28

-all direct and indirect sunlight during the daytime and is considered the primary zeitgeber for the human circadian rhythm.
-light has the greatest influence on the sleep-wake cycle.
-if the amount of of light detected increases, melatonin production is
suppressed, which promotes wakefulness.
-If the amount of light detected decreases, more melatonin is released, thereby promoting sleepiness.

-the circadian system can synchronise daily to keep in sync with the external environment (beneficial).
- since the invention of artificial lighting, our light exposure is no longer just from the Sun during daylight hours.
-24-hour access to light means we can undertake activities at night-time that were previously restricted to daylight hours. However, this can be at the expense of our wellbeing.

Question 29

1. LIGHT
   blue light

Answer 29

-a part of the visible light spectrum that is emitted from smartphone screens, computer monitors, televisions, LED and fluorescent light bulbs, as well as sunlight.

-has the most influence on the circadian rhythm through its powerful inhibition of melatonin.
-exposure to blue light at the wrong times can reduce the quality and quantity of sleep as well as contributes to many types of sleep
disorders and poor mental and physical wellbeing.

Question 30

1. LIGHT
   blue light CONT.

Answer 30

• people can have a lot of influence over their exposure to light and they can adapt and use this zeitgeber to shift a disrupted sleep–wake cycle and improve their mental wellbeing.
• It is recommended that healthy people with no sleep disorders expose themselves to natural daylight in the morning and throughout the day, and then block out artificial light (blue light) at night before sleep.
  -consistent exposure to light at
  appropriate times can help reinforce a regular sleep–wake cycle.

Question 31

1. LIGHT
   ways to reduce blue light from electronic devices in the evenings:

Answer 31

-use in-built screen filters and ‘night mode’ settings
-reduce screen brightness levels
-do not use screens before bed at all -Dimming LED room lights
-using red or orange lamps
-blue light glasses

Question 32

1. LIGHT
   using blue light to improve wellbeing:

Answer 32

-Blue light can keep a person alert while improving performance and mood
-Increasing the blue portion of
artificial light during appropriate times such as daylight hours could improve student learning in schools, the performance of indoor employees or the mood of people in hospitals and nursing homes

Question 33

2. TEMPERATURE

Answer 33

-People can use the zeitgeber of temperature to improve their sleep–wake cycle by implementing daily behaviours that support the link between temperature and the mechanisms of sleep.

Question 34

2. TEMPERATURE
   body temperature

Answer 34

-another biological mechanism that is regulated on a 24-hour circadian
rhythm controlled by the suprachiasmatic nucleus, and it is linked to the sleep–wake cycle.
-Body temperature begins to decrease in the early evening, with sleep onset occurring when core body temperature is at its greatest rate of decline.
- An increase in blood flow to the skin results in skin warming and so heat is lost from the body and body temperature drops.
-The lowest body temperature occurs at about 2 hours after sleep onset.
-The idea that skin warming helps to initiate sleep is supported by behavioural evidence of using bedding to provide warmth before/during sleep

Question 35

2. TEMPERATURE
   how to promote sleep

Answer 35

• the ideal room temperature for sleep onset is 19–21°C
  -the ideal skin and bed microclimate is 31–35°C for people during sleep
  -This means that the combination of a cool room and warm bedding is an easy way that most people can promote sleep (use of windows, fans, appropriate bedding, sleepwear, curtains, and appropriate mattress and pillow)
  -these strategies may be of particular use to the elderly age group because they typically have more trouble with normal thermoregulation

Question 36

2. TEMPERATURE
   temperature cont.

Answer 36

-subtle skin warming significantly restored the age-related decrease in deep sleep and reduced early morning awakening.
-Regulating temperature can help a person to initiate sleep quickly and
maintain sleep throughout the night, improving consistency of the sleep–wake cycle and therefore mental wellbeing

Question 37

3. EATING AND DRINKING PATTERNS

Answer 37

-The SCN is not largely influenced by the timing of meals, provided enough food is ingested.
- However, the SCN is affected by long-term severe food deprivation, calorie restriction and perceived starvation
-Acting alongside the SCN, other
peripheral body clocks exist in almost all other body tissues.
-These secondary clocks receive
daily resetting signals from the suprachiasmatic nucleus.
-They are also influenced by other
zeitgebers, particularly the timing of meals

Question 38

3. EATING AND DRINKING PATTERNS
   eating and drinking patterns cont.

Answer 38

-The SCN maintains the 24-hour cycle, keeping a daily rhythm for food intake and allowing for variation in energy metabolism and insulin sensitivity over the day.
-for optimal energy balance, the peripheral clocks should be synchronised with the SCN

Question 39

3. EATING AND DRINKING PATTERNS

Question 40

3. EATING AND DRINKING PATTERNS
   inconsistent/disrupted patterns

Answer 40

• people who routinely consume food during the active, daylight phase of the 24-hour cycle, the suprachiasmatic nucleus and peripheral clocks remain synchronised, allowing for a consistent and appropriate sleep–wake cycle.
  -if a person begins to alter the timing, amount and composition of their meals to the inactive, dark phase of the 24-hour cycle, the mealtimes are now in misalignment with the routine light–dark
  cycle of the day.
  -This influences the peripheral clock timing, and leads to an uncoupling of the peripheral clocks from the SCN.

-the presence of a mealtime zeitgeber outside the usual time, particularly during the inactive phase of the day–night cycle, can disrupt and cause a shift in normal functioning of the body clock.
-In this case, the suprachiasmatic nucleus remains entrained to the daylight cycle, but food is not being consumed when the regular circadian endocrine responses to food intake are being conducted.

Question 41

3. EATING AND DRINKING PATTERNS
   inconsistent/disrupted patterns (EXAMPLE)

Answer 41

• if a person starts to regularly stay awake until the early hours of the morning
  and eats large meals very late at night during their usual inactive phase, the messages being sent to their peripheral clocks will now be at odds with the suprachiasmatic nucleus, which is still trying to maintain a consistent sleep–wake cycle according to light.
• Effectively, the peripheral clocks act as though it is daytime because of food consumption, but the SCN acts as though it is night-time because of the low light exposure.
  -This shifts the circadian rhythm out of the day–night cycle.

Question 42

3. EATING AND DRINKING PATTERNS
   non-ideal timing of meals

Answer 42

• eating meals within 3–4 hours of the onset of sleep can negatively affect sleep quality, increase sleep onset time and increase awakenings.
  -caffeine consumption correlates with increased sleep problems, including morning tiredness, increased awakenings, restless sleep and reduced sleep quality.
  -caffeine may still affect sleep sleep if consumed up to 6 hours before sleep.

Question 43

3. EATING AND DRINKING PATTERNS
   adjusting meal timing

Answer 43

• can easily adjust, and dietary interventions can help reduce the development of health problems and improve the sleep–wake cycle.
  -Limiting caffeine intake later in the day and not eating right before sleep can help sleep onset and quality.
  -Bringing mealtimes back to a normal schedule during the active, light phase of the day, as well as leaving a sufficiently long fasting window during the circadian inactive phase of night, will allow the peripheral clocks to resynchronise with the
  SCN.

-These daily habits when used alongside appropriate light exposure, can help provide an additional signal to form a consistent sleep–wake cycle, protect against physical health problems and aid in mental wellbeing.