Sleep Deprivation
a state caused by inadequate quantity or quality of sleep
Sleep quantity
refers to the amount of sleep usually measured objectively in terms of total time spent asleep
Sleep quality
refers to how well we feel we have slept – which is typically
assessed subjectively using self-report measures
Partial sleep deprivation
involves having less sleep (either quantity or quality) than what is normally required
Affective effects of partial sleep deprivation
changes in emotions and emotional responses from sleep deprivation
Behavioural effects of partial sleep deprivation
observable changes in actions and the ability to control actions that arise from sleep deprivation
Cognitive effects of partial sleep deprivation
changes in mental processes that arise from sleep deprivation
BAC and partial sleep deprivation
17 hours of sleeplessness (partial sleep deprivation) is equivalent to a BAC of 0.05%
BAC and total sleep deprivation
24 hours sleeplessness (total sleep deprivation) is equivalent to a BAC of 0.1%
Sleep disorders
a sleep disturbance that regularly disrupts sleep and causes distress or impairment in everyday functioning
Circadian phase disorders
involve persistent sleep disruption due to a mismatch between and individuals circadian sleep-wake cycle and the desired or required sleep-wake cycle
Delayed Sleep Phase Syndrome (DSPS)
a sleep disorder where the major sleep episode is shifted later in relation to the desired/conventional sleep time. Falling asleep later and waking up later
Advanced sleep phase disorder (ASPD)
a sleep disorder where the major sleep episode is shifted earlier in relation to the desired conventional sleep time
Shift work sleep disorder
can result when a persons work hours are scheduled outside of the normal waking day, which causes a mismatch between their circadian sleep-wake cycle and the day-night of the external environment. Internal cues don’t match external cues. they need to be awake at times that melatonin is naturally higher
Bright Light Therapy (BLT)
involves timed exposure of the eyes to intense but safe amounts of light (either natural or artificial) used to reset the biological clock and gradually shift someone’s circadian sleep-wake cycle to a more appropriate schedule
Sleep hygiene
involves engaging in behaviours and changing environmental factors (zeitgebers) to promote adequate quantity and quality of sleep, along with daytime alertness. Required for good physical and mental wellbeing
Adaptation to zeitgebers
the SCN uses Zeitgebers (environmental cues) to adjust ones circadian rhythm to match the day-night cycle of 24 hours (process called entrainment). This promotes sleepiness and wakefulness at appropriate times. These are, daylight and blue light, temperature, eating and drinking patterns
Blue Light impact on the sleep wake cycle
suppresses the secretion of melatonin that makes feel drowsy, resulting in increased feelings of alertness. Prolongs sleep onset, reduce amount of time spent in NREM 3 and REM, increase frequency of awakenings, contribute to morning sleepiness
To improve sleep and wellbeing - light
- keep bedroom in darkness
- close-fitting eyemask
- limit exposure to blue light in 1-2 hours before bed
- use night mode settings
Temperature of the Body
body temp decreases during sleep phase (1 degree), linked with release of melatonin, then rises during wake phase with release of cortisol
To improve sleep and wellbeing - temperature
a room temp of around 19-21 degrees will help regulate core body temp, in combination with warm bedding can promote good sleep quantity and quality
Eating and drinking patterns
the circadian sleep wake cycle prepares the body to be more efficient and metabolising food earlier in the day when we are active (melatonin impacts ability to metabolise)
To improve sleep and wellbeing
- eat bigger meals earlier in the day, stay away from large meals before bedtime
- avoid foods with sugar and caffeine (stimulate CNS, increase heart rate)
- avoid alcohol before bedtime as this will disrupt sleep quality
