Define sleep deprivation.
A general term used to describe a state caused by inadequate quantity or quality of sleep.
What are circadian rhythm sleep disorders?
A group of sleep disorders involving sleep disturbance due to a mismatch between an individual's sleep-wake schedule and what is required.
What is the goal of phototherapy?
To help shift the biological clock so that sleep patterns are more aligned with the environment and the individual can experience better sleep (in quantity and quality).
Define sleep hygiene.
Practices that tend to improve and maintain good sleep and full daytime alertness.
What are zeitgebers?
Environmental time cues.
17 hours and 24 hours
What percentage of adolescents/young adults suffer from DSPS?
7-15%
True or false: doing one session of bright light therapy will cure all sleep disorders.
False. Bright light therapy requires a number of sessions over several days for the body to adjust to the new schedule. These sessions can last from 15 minutes to two hours (1-2 times a day), depending on many factors.
Ideally, at what point in the day should someone with good sleep hygiene be exercising?
During the daytime or at least 4-5 hours prior to bedtime.
List three examples of zeitgebers.
Clocks, alarms, school bells, timetables, workplace routines, eating and drinking patterns, social routines, newsfeeds, noise, exercise routines, medications, atmospheric conditions.
Partial: having less sleep, in either quality or quantity, than required/needed. May occur periodically or persistently over the short-term or long-term.
Total: not having any sleep at all over a short-term or long-term period (one or more days or weeks). People often use stimulants to help them remain awake for such a long time.
Sleep-onset insomnia, difficulty awakening at necessary time and excessive sleepiness.
Outline phototherapy and its purpose.
Timed exposure of the eyes to intense, safe amounts of light (either natural or artificial) aiming to shift an individual's sleep-wake cycle to a desired schedule.
True or false: going to sleep at random times every day is a good sleep hygiene practice.
False. It is beneficial to establish and maintain a regular sleep-wake pattern. Aim for the pattern to be the same 7 days a week.
How does light influence sleep?
Directly by making it difficult for people to fall asleep and indirectly by influencing the timing of the SCN activity and therefore preferred sleep time.
Explain the relationship between sleep deprivation and microsleeps.
When sleep-deprived, an individual can feel fatigued or excessively sleepy, contributing to drowsiness, difficulty concentrating and reduced awareness and efficiency. Due to this, an individual may fall into involuntary lapses of sleep that last around 1-15 seconds (microsleeps), where they will briefly close their eyes and become less responsive to external stimuli.
Suggest some ways that jobs that involve shift work can best accommodate their rosters to create the least sleep disturbances for employees.
They could implement fixed rosters rather than rotating ones. If rotating rosters are necessary, they should aim to have the same individual working on each shift for longer periods before changing (three-week over one-week rotations). Furthermore, it is easier for individuals to adapt when shifts become successively later (i.e. moving from a 7am-3pm shift to an 11pm-7am shift)
An adolescent who finds it hard to stay awake at school finds it hard to fall asleep at night despite being tired. At what time should they administer bright light therapy? Explain.
They should administer bright light therapy in the early morning before going to school to help with wakefulness and help them feel tired earlier later on in the day and hopefully diminish how hard they find it to fall asleep.
What are some stimulating activities that should be avoided before bed?
What is thermoregulation and how does it affect an individual's sleep?
Thermoregulation is the body's control of its core temperature. It gradually decreases as the individual approaches the nighttime sleep phase. Decreasing air temperature can be used as a zeitgeber to signal the body to get ready for sleep.
Describe how sleep deprivation can affect functioning (affective, behavioural and cognitive)
Affective (emotional): amplified emotional responses that tend to be more intense and exaggerated. We might become more irritable and find it harder to control impulses.
Behavioural: excessive sleepiness and fatigue. Decreased awareness of the environment leads to higher risk-taking behaviour. We also experience reduced motor coordination and accuracy.
Cognitive: reduced alertness and capacity to sustain attention. Our ability to think clearly and complexly is also impaired, making it more difficult to problem-solve. In children, it reduces verbal creativity and in adults, it impairs various learning and memory processes.
Draw a timeline comparing the sleep cycle of someone with ASPD, DSPS and a normal sleep phase.
Explain how bright light therapy can be used to treat the three main sleep disorders.
DSPS: light exposure in the early morning hours to help advance the circadian rhythm to an earlier time, causing the person to feel sleepier earlier once it is time for them to sleep and therefore wake up earlier the next day.
ASPD: light exposure in the evening/early night to help delay the circadian rhythm to a later time so that the person will experience sleepiness later and therefore be able to wake up later.
Shift work-related disorders: light treatment in the evenings for someone who works at night, avoiding light during daytime so that it can be used to rest.
Why should you avoid alcohol too close to bedtime?
Although it can speed up sleep onset, it can disrupt the second half of the sleep episode as the body metabolises the alcohol. This can cause arousal and make it harder to stay asleep.
What role do zeitgebers play in the entrainment of circadian rhythms?
Zeitgebers are used by the SCN to adjust circadian rhythms to a 24-hour day. When the SCN resets/adjusts the sleep-wake cycle due to the influence of a zeitgeber, the circadian rhythm undergoes the process of entrainment.