Starter Using the following terms. Write up the outline for Circadian Rhythms and sleep Endogenous Pacemaker Internal Exogenous Zeitgebers light Melatonin Superchiasmatic nucleus Pineal Gland Temperature

Board: Grounding Group task I am going to show you a picture related to a piece of research You must find the study on page 5 that links To get the points on the w/b you must explain the study and provide a full grounding Bonus points for any relevant/useful evaluation you can consider P5

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Evaluation of Research Controlled conditions increase confidence in validity. Schochat’s research took place in a well controlled laboratory environment.  Correlation criticisms. Schochat’s relationship is correlational so only proves a relationship not the cause of the relationship. However insomniacs treated with melatonin do find it easier to sleep.  Validity of animal research is questionable. Extrapolation from animals to humans is an issue in Morgan’s hamster study, though no reason to suppose it would be any different.

Appropriate IDA? Can we change our cycles?

Nature vs Nurture or Determinism IDA- A mixture of environmental and biological determinism interact to control your circadian rhythms. This is because we definitely know that our circadian rhythms are controlled by endogenous i.e. biological factors, however as exogenous zeitgebers for instance light can have an impact on these rhythms that there is an element of the environment also. So the theory is an interact of the two and this is definitive.

IDA example for the Circadian Rhythm The Point: The theory enables us to understand how both ____________ ______________ and ______________ ________________ act together to control the rhythm Explain the Point: This is because the theory show that while __________ _________ such as the role of the SCN largely control the rhythm, ___________ _____________, such as light, play a part in … Resetting the rhythm So What? The greater understanding that the theory gives us of how the circadian rhythm is controlled, may lead to useful… Applications As it could help us to deal with… People who have circadian rhythm disorders more effectively It could also help us to minimise the unpleasant and harmful effects of Shift work and Jet Lag pacemakers Exogenous Biological Environmental determinism Endogenous zeitgebers

Practical Applications 1.Sleep Hygiene 2.Use of devices 3.Taking of medication/treatment 4.Work/study schedules 5.Fitness/ sport regime On the whiteboard, write a paragraph on one of the above practical applications

How could the following effect circadian rhythms? Page 11 1.Jet Lag 2.Shift work Use the following terms Zeitgebers, internal and external, disrupts,

Ultradian Rhythms

Ultradian rhythms are rhythms that have a period shorter than 24 hours. There are many different ultradian rhythms � eye blinks (24 eye blinks per minute in humans), respiration, heartbeat and sleep patterns. Sleep patterns Although the sleep-wake cycle is a circadian rhythm, there are patterns within sleep as well. When we go to sleep, it is not one long snooze, but instead a set several sleep cycles that each last approximately 90 minutes. In the sleep cycles there are two main stages, non-REM sleep and REM sleep. In non-REM sleep there is a progression though 4 stages from stage 2 (an effective � baseline � state that occupies 50-65% of sleep time) to stages 3 and 4, often called slow wave sleep as an electroencephalogram (EEG) will show high voltage slow brain waves at this stage. After approximately 20 minutes of slow wave sleep there is a quick transition back to stage 2 sleep and from there into REM sleep. REM (rapid eye movement) sleep is characterised by rapid eye movements, depression of spinal reflexes and an increase in heart rate and respiration. During REM sleep, and EEG of a person � s brain activity produces a trace to similar to that when they are awake. However there is no ability to move skeletal muscles and the person is still in deep sleep. After minutes of REM sleep there is a return to stage 2 sleep. This cycle is repeated every minutes throughout the night with the slow wave stage getting shorter and the REM stage getting longer as the night progresses (Different Stages of Sleep site 2002).

Ultradian rhythms How do we measure this? Match them up Muscles?, electrical activity?, eye movements? Electroencephalographs (EEGs) Electro-Oculograms (EOGs) Electromyograms (EMGs)

Outline one or more examples of Ultradian rhythms. (4 marks) Ultradian rhythms are rhythms that have a cycle length of more than one cycle every _________. The sleep cycle is an ultradian rhythm and most people have _____ cycles of sleep that last approximately ___ minutes each night. There are two classifications of sleep, _____ and _____. _____ consists of 4 stages and REM sleep is the final stage of the sleep cycle. In the first two cycles, the sleeper descends through the lighter stages of sleep (stages 1-3) into the _________ stage of sleep (stage 4), then onto ____ sleep for around ____ minutes. In the last 3 cycles, the sleeper moves from stage 2 straight to REM and periods of REM get increasingly longer.

Outline one or more examples of ultradian rhythms. (4 marks) Ultradian rhythms are rhythms that have a cycle length of more than one cycle every 24 hours. The sleep cycle is an ultradian rhythm and most people have five cycles of sleep that last approximately 90 minutes each night. There are two classifications of sleep, NREM & REM. NREM consists of 4 stages and REM sleep is the final stage of the sleep cycle. In the first two cycles, the sleeper descends through the lighter stages of sleep (stages 1-3) into the deeper stage of sleep (stage 4), then onto REM sleep for around 10 minutes. In the last 3 cycles, the sleeper moves from stage 2 straight to REM and periods of REM get increasingly longer.

Research activity Represent each study using only images Dement and Kleitman (1957) Wehr (1992) Ekirch (2001) Best drawings win a sticker Whilst doing this individually Ground studies >>>>>>>>> 7/8

Sleep is measured in a laboratory Why does this way of studying the ultradian rhythm give objective and replicable evidence? Also comment on why objectivity and replicability are positive qualities for evidence to have. Add to page 7

IDA Example for Ultradian Rhythms: The Sleep Cycle The Point: Biological determinism Nature nurture Reductionism Explain the Point: Little Free will Simplistic- ignores cultural/societal factors Simplistic- Does not fully exaplain external influences So What? Research methodology evaluation Implications Usefulness 8