Sleep DP 4-6

What is sleep deprivation?

A state caused by inadequate quality and quantity of sleep, and is either voluntary or involuntary.

Total sleep deprivation

Involves not having any sleep at all over a short0term or long-term

Partial sleep deprivation

Involves having less quality or quantity of sleep than what is normally required, which leads to the accumulation of sleep debt overtime (hours do not have to be fully repaid).

-Can occur periodically or persistently over a short-term or long-term

-Effects tend to be minor and temporary

Compare effects of one night of full sleep deprivation with BAC

The higher a person’s BAC (blood alcohol percentage), the more their cognition, concentration and mood might be impaired

-17 hours of full sleep deprivation is equivalent to the BAC reading of 0.05%

-24 hours of full sleep deprivation is equivalent to the BAC reading of 0.10%

The legal BAC is 0.05%

Identify the three effects of partial sleep deprivation (a, b, c’s)

Affective functioning, behavioural functioning, cognitive functioning

How is affective functioning impacted by sleep deprivation

-Interferes with emotional regulation and reactivity (more likely with REM Deprivation)

-Amplified emotional responses- easily irritated, frustrated, and aggressive (harder to control impulses)

-Reduced emotional empathy, harder for individual to accurately judge others emotions and reactions (facial recognition of emotions decline)

How is behavioural functioning affected by sleep deprivation

-Microsleep (sleep episode that lasts for a few seconds), and sleep intertia (temporary period of reduced alertness and performance impairment that occurs immediately after awakening) occurs

-Slower reaction times

-Excessive sleepiness when awake (fatigue, drowsiness)

-Difficulty in maintaining focus and concentration

-Risk-taking behaviour

How is cognitive functioning affected by sleep deprivation?

Worser performance on simply or repetitive tasks, impaired cognitive functioning.

-Reduced ability to divide attention and think clearly, likely to think irrationally, difficulties in decision making and creative thinking, ability to process information impaired.

What are circadian rhythm sleep disorders?

-Sleep disorders involving sleep disturbance that is primarily due to mismatch between an individual’s sleep-wake pattern and the pattern that is desired.

What may cause circadian rhythm sleep disorders?

-Natural malfunctions in biological mechanisms

-External environment

-Social schedule

Examples of circadian rhythm sleep disorders

Delayed sleep phase syndrome (DSPS), Advanced Sleep Phase Disorder (ASPD), and shift work disorder.

What is Delayed sleep phase syndrome (DSPS)

When a major sleep episode is delayed in relation to desired/conventional time. Mainly prevalent in elderly, may be due to the earlier release of cortisol or melatonin.

-Related to sleep-onset insomnia (difficulties in falling asleep)

-Difficulties wakening, excessive sleepiness in day

-Mismatches with times cues in environment

-Worsens in adolescence and early adulthood

What is Shift Work Disorder

A sleep disorder that results from work shifts in regular sleep periods

-Causes insomnia and excessive sleepiness during work due to reduction in total sleep time and the individual trying to be asleep at times the body expects to be awake

What has a higher frequency of sleep disturbance: Rotating shifts or fixed shifts?

-Rotating shifts have a higher frequency of sleep disturbance than fixed shifts- moving shift forward is better than backwards for shift work disorder

Who is mainly affected by shift work disorder?

-Police, paramedics, firefighters, doctors and nurses, airport/airline staff, border/immigration staff, transport drivers

What is Advanced Sleep Phases Disorder (ASPD)?

-Rare disorder more common in older people, caused by the persistent disturbance of sleep due to timing of major sleep episode occurring earlier than desired time.

-leads to early morning insomnia (struggle to stay awake and go back to sleep), persistent sleep deprivation and daytime sleepiness

-May be due to deterioration in biological clock or the earlier release of melatonin or cortisol.

Define bright light therapy

Timed exposure to safe but intense amounts of light which aims to shift the sleep-wake cycle to its desired schedule, it inhibits melatonin secretion from the pineal gland, and therapy is gradual (45 minutes per day)

-AKA phototherapy

What are the three important variables for bright light therapy?

1. The right time of day

2. The right intensity of light

3. The right amount of time

How does bright light therapy work?

Bright light therapy involves timed exposure of the eyes to intense but safe amounts of light, aims to shift the sleep-wake cycle to the desired schedule and inhibits melatonin secretion from the pineal gland.

-various lamps, visors, and other devices are used

-The light used is brighter than indoor light but not as bright as direct sunlight

-No major side effects, only minor (e.g dry skin, headache, eye irritation)

How can bright light therapy be used for DSPS? (Delayed sleep phase syndrome)

Delayed sleep phases syndrome causes a sleep-wake cycle shift, and is common amongst adolescents

-DSPS leads to waking time being later in the morning, so light exposure during early morning hours (e.g 6am-8am), which helps to shift cycle forward and make individual sleeping earlier.

How can bright light therapy be used for ASPD? (Advanced sleep phase disorder)

-Advanced sleep phase disorder (ASPD) is a disorder that leads to wakening earlier than desired, and mostly affects the circadian rhythms of the elderly.

-Light exposure early in the evening (e.g 7-8pm) helps shift the cycle back and make individual sleepy later.

How can bright light therapy be used for shift work sleep disorder?

Shift work sleep disorder occurs mostly for night shift workers, who, try and sleep at times the body expects to be awake.

-Using bright light therapy in the evening can help individuals with regular working nights, but can be difficult when shifts are irregular

-Daylight should be avoided between shifts (wear dark sunglasses)

What are the three important variables of bright light therapy?

-The right time of day (the peak time: how close the individual is exposed to light to optimal time; determined by core body temperature

-The right intensity of light

-The amount of time (45 minutes)

What is a zeitgeber?

-Environmental time cues that are used by the SCN/biological clock to adjust circadian rhythms so that they are aligned with the 24 hour day/day night cycle of our external environment

What are some different types of zeitgebers?

Daylight, blue light, temperature, eating and drinking patterns

State source in environment and example of how the zeitgeber daylight may be used, and why this would have the desired effect.

The zeitgeber daylight is sourced by sunlight in the environment.

-may be used by seeking exposure in the daytime and gradually reducing exposure from late afternoon early evening prior to bedtime

-This would have the desired effect as timing of light exposure will promote or suppress melatonin secretion, and sleep is more likely to occur when melatonin level rises

State source in environment and example of how the zeitgeber blue light may be used, and why this would have the desired effect

Sourced by sunlight and electronic devices

-may be used by seeking exposure in the daytime and gradually reducing exposure from late afternoon early evening prior to bedtime

-This would have the desired effect as timing of light exposure will promote or suppress melatonin secretion, and sleep is more likely to occur when melatonin level rises

State source in environment and example of how the zeitgeber temperature may be used, and why this would have the desired effect

Sourced by the atmosphere

-May be used by adjusting temperature to match with natural/circadian drop in core body temperature in the evening. The ideal room temperature for sleep onset is 19-21 degrees Celsius, and the ideal skin and bed microclimate is 31-35 degrees Celsius.

-Sleep is more likely to occur when core body temperature decreases in the evening/is aligned with other environmental and circadian changes (e.g. darkness, increased melatonin level)

State source in environment and example of how the zeitgeber eating and drinking patterns may be used, and why this would have the desired effect

-Sourced by meals, snacks, and drinks

-May be used by maintaining routine meal and drink times in sync with desired sleep wake cycle and avoiding erratic schedules

-This would have the desired effect as sleep is more likely to occur when eating and drinking patterns, sleep patterns, and the environmental day/night pattern and other zeitgebers are aligned.

What is sleep hygiene?

-Practices that tend to improve and maintain good sleep and full daytime alertness.

What are the 10 good sleep prac

1. Establish a regular relaxing sleep schedule and bedtime routine.

2. Associate your bed and bedroom with sleep.

3. Avoid activities that are stimulating in the hour before bed.

4. When you cannot sleep get up.

5. Avoid napping during the normal waking period.

6. Avoid stimulants such as caffeine, nicotine and alcohol too close to bedtime.

7. Exercise can promote good sleep.

8. Food can be disruptive just before sleep.

9. Improve your sleeping environment.

10. Ensure adequate exposure to natural light.