Sleep-wake cycle VCE PSYCHOLOGY UNIT 4 Presented by Kristy Kendall Study design dot points: changes to a person’s sleep-wake cycle and susceptibility to experiencing a circadian phase disorder, including sleep-wake shifts in adolescence, shift work and jet lag the interventions to treat sleep disorders including cognitive behavioural therapy (with reference to insomnia) and bright light therapy (with reference to circadian phase disorders).

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Sleep-wake cycle

Owl or lark? Sleep quiz activity https://pixabay.com/en/owl-animal-bird-computer-funny-158414/ http://www.surrey.ac.uk/features/sleep-quiz-are-you-owl-or-lark Source: Pixabay

Sleep-wake cycle Our bodies are tuned into a 24 hour sleep- wake cycle which is a regular circadian rhythm. It is determined by an internal body clock located in the hypothalamus. This clock also regulates our level of arousal, metabolism, body temperature and hormone secretions.

Circadian phase disorders Sleep disruption due to alteration of the internal circadian rhythm. Can be characterised by an inability to fall asleep or to remain asleep Caused by a variety of reasons including: lifestyle factors genetics shift work jetlag adolescence, etc.. Can result in: insomnia impairment in social and occupational functioning. Source: Pixabay

Factors that effect the sleep-wake cycle Lifestyle Factors that effect the sleep-wake cycle Shiftwork Stressful or low stress job Active or inactive lifestyle Diet and health (stimulants) Good sleepers are more likely to have a more regular sleep routine than poor sleepers. Source: http://www.freepik.com/free-vector/neon-signs-collection_739265.htm

Factors that effect the sleep-wake cycle Genetics Factors that effect the sleep-wake cycle Studies found identical twins have more similar sleep patterns then fraternal twins. Studies also suggest females tend to need more sleep than males. Source: http://www.freepik.com/free-photo/sisters-using-an-open-book-as-an-umbrella_867236.htm#term=twins identical&page=1&position=0

Factors that effect the sleep-wake cycle Jetlag Factors that effect the sleep-wake cycle Change of time zones West is best…gaining and losing time No attribution required: https://www.pexels.com/photo/flight-sky-airplane-travel-127441/ Image purchased from: Source: Shutterstock

Ways to help reduce jetlag Factors that effect the sleep-wake cycle Video source: https://www.youtube.com/watch?v=sbNkAcfNhh0

Factors that effect the sleep-wake cycle Adolescence Factors that effect the sleep-wake cycle During adolescence the sleep/wake pattern shifts towards the evening (phase delay). Also known as delayed sleep onset. Particularly dangerous because adolescents need far more sleep than an adults Why does delayed sleep onset occur? Melatonin is a hormone that helps to induce sleep. During adolescence the release of this hormone is delayed for up to 2 hours. Melatonin release is controlled by circadian rhythms but can also be effected by light. It is also thought social factors can impact (e.g. homework demands, after school activities, internet). No image attribution required https://www.pexels.com/photo/laptop-computer-turned-on-while-in-dark-area-30814/ https://www.pexels.com/photo/mokup-smartphone-technology-phone-34407/

Impact of delayed sleep onset Can create a vicious cycle… This can lead to circadian phase disorder which causes extreme difficulty falling asleep and sleepiness when waking in the morning.

Treatment of circadian phase disorders Light therapy can be used to re-set the body’s internal clock. During light therapy your eyes are exposed to intense but safe amounts of light for a specific and regular length of time as artificial light may be used to affect the body clock in the same way that sunlight does. Source: Pixabayz https://pixabay.com/en/lamp-lit-thought-light-bulb-shine-306201/

25 hour cycle? http://www.ncbi.nlm.nih.gov/books/NBK10839/

Multiple choice activity The sleep-wake cycle shift during adolescence is typically caused by A. depression and the sleep debt. B. delayed release of the hormone adrenaline. C. delayed release of the hormone melatonin. D. overproduction of the hormone melatonin. (VCAA 2013 Exam Q19)

Multiple choice - response The sleep-wake cycle shift during adolescence is typically caused by A. depression and the sleep debt. B. delayed release of the hormone adrenaline. C. delayed release of the hormone melatonin. D. overproduction of the hormone melatonin. (VCAA 2013 Exam Q19)

Fast five: Question 1 What sort of rhythm is our sleep wake cycle on?

Question 1 (Response) What sort of rhythm is our sleep wake cycle on? Answer: Circadian

Fast five: Question 2 A shift from one country to another can result in negative effects known as _____________.

Question 2 (Response) A shift from one country to another can result in negative effects known as _____________. Answer: Jetlag

Fast five: Question 3 T/F: Genetics can play a role in circadian phase disorders.

Question 3 (Response) T/F: Genetics can play a role in circadian phase disorders. Answer: True

Fast five: Question 4 A delayed release of which hormone can cause delayed sleep onset in adolescence?

Question 4 (Response) A delayed release of which hormone can cause delayed sleep onset in adolescence? Answer: Melatonin

Fast five: Question 5 A great way to reset the internal body clock is thought to be through ___________ therapy.

Question 5 (Response) A great way to reset the internal body clock is thought to be through ___________ therapy. Answer: Light

Sleep-wake cycle VCE PSYCHOLOGY UNIT 4 Study design dot points: changes to a person’s sleep-wake cycle and susceptibility to experiencing a circadian phase disorder, including sleep-wake shifts in adolescence, shift work and jet lag the interventions to treat sleep disorders including cognitive behavioural therapy (with reference to insomnia) and bright light therapy (with reference to circadian phase disorders).

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