Homework Psych205 > A2 Psychology > Unit 3 > Biorhythms > functions of sleep > complete all activities on evolution and restoration theories

Exam Prep stations You will have 10 minutes to complete each activity 1.Revise 2.Plan 3.Assess and analyse

Revise Rhythm/TopicResearch evaluation points IDA (can be more than one) Wider evaluation Application/Issues/ IDA

Plan In pairs plan an essay for the following essay title (10 minutes) Discuss the role of endogenous pacemakers in the control of one biological rhythm ( marks)

Assess and Analyse Individually read and highlight the mark scheme What are the main messages from the mark scheme? Is there anything else you would include in your plan?

Disruption of biological rhythms Jet lag and shift work

Quiz

On the w/b Discuss- How could the following effect circadian rhythms? 1.Jet Lag 2.Shift work Use the following terms Zeitgebers, internal and external, disrupts,

Watch the video 8QC4 8QC4 Note the explanation of jet lag List the effects of Jet lag List the studies findings List ways to manage jet lag

Disrupution- Jet Lag Travelling from east to west leads to phase delay of the body clock, which seems easier for the body to cope with than phase advance. Phase delay simply means extending the duration of a rhythm’s cycle (e.g. from 24 hours to 29 hours before returning to 24 hours again), Phase advance means shortening the rhythm’s cycle.

Handout – Jet lag Cho (2001) studied the long term effects of travelling across time zones. Air crew regularly flying over 7 time zones with little turn-around time were found to have significantly higher levels of cortisol (a stress hormone) than those on short flights. The level of cortisol was associated with deficits in memory and spatial learning, although it may take five years before the effects are seen. Schwartz et al (1995) analysed the results of American baseball games where teams had to travel across time zones to play opposing teams on the east or west coast, causing a time difference of three hours. West coast teams who travelled east had significantly fewer wins than the east coast teams who travelled west. Klein et al (1972) confirmed the view that flying west to east caused more jet lag than flying east to west by looking at flights from the UK from the US. They also found that one day per time zone crossed (each time zone is one hour) was needed for full recovery

Shift work IJ1U IJ1U Note the link between shift work and diabetes Explain why

Handout- Shift work Knutsson et al (1986) found that individuals who worked shifts for more than 15 years were three times more likely to develop heart disease than non-shift workers. Hansen et al’s (2012) study of 692 women from the Danish military found a link between the two. Hansen still found that working night shifts was associated with a 40% increase in breast cancer risk. The more nights shifts worked, the greater the risk of breast cancer. Hansen also found that shift workers who described themselves as being “morning” people — that is, they preferred to wake up early, rather than stay up late at night — had a four times higher risk of breast cancer than women who worked during the day. However Fritschi (2012) An Australian study of 1000 women showed no link between breast cancer and shift work. Burch et al. (2005) found that night workers’ melatonin levels (measured in their urine) and sleep patterns were disrupted compared with day workers’. The night workers’ melatonin levels were too high, making them sleepy and prone to accidents.

Evaluation 1.Socially sensitive 2.Biological approach 3.Nature/Nurture 4.PRACTICAL APPLICATIONS

Practical Applications Should consider both- The beneficial effects of altering shift work patterns Effects of jet lag on physical health.

Practical applications: Jet lag: Consuming melatonin may help resynchronise the sleep-wake cycle more quickly. Beaumont et al (2004) found that taking melatonin at bed time for 3 days before travel and 5 days after significantly reduced the symptoms of jet lag Exposure to light can affect circadian rhythms. Burgess et al (2003) investigated if jet lag could be prevented by phase shifting (advance or delay) before travelling. They found that after three days of light exposure in the morning, the participants’ circadian rhythms shifted by an average of 2.1 hours. This means they would feel less jet lagged, and would be fully adjusted to the new time zone around two days earlier. Shift work: The research can help both those planning work schedules and workers. Czeisler et al (1982) proposed that it would be better to rotate shifts forward in time so one begins with a day shift, progresses to an evening shift and then turns to a night shift. They found that workers reported feeling better and much less tired on the job. The management reported increased productivity and fewer errors. Dawson & Campbell (1991) found that workers exposed to a 4-hour pulse of bright light showed improvements in work performance. This shows that light acts as an exogenous zeitgeber in maintaining the rhythm of the SCN. Consequently, bright light has been used as a substitute for sunlight to reset the SCN.

Practical applications Activity Match the policy to the research and explain why it links 1.Amazon has introduced a policy to rotate shifts so that workers in their factories start with a day shift. This is supported by research by… 2.A doctor has advised a patient to take melatonin supplements before a trip to Australia… 3.The NHS is advising exposing yourself to light early in the morning when suffering from jet lag…. 4.Nurses in one ward are being encourage to received “light therapy” treatment where they are exposed to pulses of bright white light during shifts….

Individually on the mwb 1.Socially sensitive 2.Biological approach 3.Nature/Nurture 4.PRACTICAL APPLICATIONS

AO1 = 8 marks Outline of research into the disruption of biological rhythms The term ‘research’ refers to both theory/explanations and studies, and so there are two possible routes through this question. One is to outline theory/explanations relevant to the disruption of biological rhythms as AO1 material, with studies as AO2/3. The other is to outline studies as AO1 and to use the implications of these studies as AO2/3. Examiners should also be alert to answers that use both approaches. In the context of biological rhythms the focus is far more likely to be on the findings of research studies. AO1 material is therefore likely to focus on research studies into shift work and jet lag, although other examples, such as seasonal affective disorder, could also be relevant if presented in the context of the disruption of biological rhythms. Effects of disrupting biological rhythms through shift work and jet lag can be behavioural (e.g. lowered productivity), psychological (e.g. tiredness, depression, anxiety), or physiological (e.g. increased vulnerability to heart disease and cancer). For each of these and for both shift work and jet lag there are many accessible research studies. More anecdotal answers that simply describe effects of disrupting biological rhythms without reference to research studies may earn marks as the description is based on research, but will not move out of Basic however accurate and detailed. Some candidates may begin by outlining the mechanisms behind the disruptive effects, such as the dislocation of endogenous pacemakers and external zeitgebers i.e. outlining an explanation for the effects of disrupting biological rhythms. This would then become AO1 material, and studies used to support or contradict this explanation would become AO2/3. Examiners should be sensitive to depth-breadth trade-offs in answers that cover two or more examples of disruption. There are no partial performance criteria for this question.

Question 01 This popular question was done reasonably well. There were a variety of routes to AO1 and AO2/3 credit; AO1 could consist of an outline of underlying mechanisms (endogenous pacemakers interacting with external zeitgebers), consequences of disrupting biological rhythms, or research studies. AO2/3 could then consist of relevant research evidence or implications of research studies. Weaker answers often confused the roles of pacemakers and zeitgebers, and failed to interpret research findings accurately. However, there has been a clear trend of improvement in the use of relevant studies from a range of areas. These include effects of shift work on mood, physical illness and productivity, the beneficial effects of altering shift work patterns, and effects of jet lag on physical health. Effective IDA in this area included the application of findings to, for example, improving the health of workers, or to reduce the effects of jet lag.

AO2/3 = 16 marks Commentary on the effects of disrupting biological rhythms Studies on jet lag or shift work in the real world raise major issues of validity and reliability that affect the generalisability of their findings. However the link between evaluative points and the reliability/validity of findings must be explicit for marks to be awarded. Comments on the consistency or otherwise of findings would also be an effective route to AO2/3 credit. Further commentary might include the implications of findings for our understanding of the mechanisms of the effects of disruption, and application of findings to reduce the impact of disruption e.g. by changes to shift work patterns, or by adjusting behaviour when crossing time zones. For full credit such applications should be linked to mechanisms/explanations. Treatments for jet lag e.g. melatonin, would be creditable as long as there is an explicit link to biological rhythms e.g. via the role of melatonin in biological clocks. For answers that present the mechanisms of disruption as AO1 material, the findings of relevant research studies would be the most accessible source of AO2/3 credit, as long as they are used to support or contradict our understanding of these mechanisms. Indicative issues, debates and approaches in the context of the disruption of biological rhythms include practical applications of findings. Some convincing studies show that modifying shift work patterns can have significant beneficial effects on behaviour and health. Other relevant IDA may include reductionism and the nature/nurture debate

Q 2 – A02/3 Examiners In relation to evaluations skills and in particular the use of Issues, Debates and Approaches (IDA) in evaluation, there is still an overreliance on rote learned lists of evaluative points. Examiners commented that in some scripts the same paragraph of generic IDA had simply been slotted into each answer, regardless of whether it was relevant or not. Similarly, methodological evaluation of studies often consisted of a list of assertions relating to gender and cultural bias, small sample size, use of questionnaires, ethical issues, etc but these were not explained or elaborated. If the question requires evaluation of theories/explanations, then methodological evaluation of studies is irrelevant unless the implications for the theory/explanation are made clear. For example, a student might argue that because the methodological criticism compromised the reliability and validity of findings so the study provides little or no support for the theory/explanation. If the relevance to the theory/explanation is not made explicit, methodological evaluation of studies will not receive credit. If the question allows for studies as AO1 material, then evaluation (including methodological issues) of those studies would qualify as AO2/3.

The Nature of Sleep This topic includes Nature of sleep (cycles) Lifespan changes and sleep 1.“Outline the nature of sleep” ( 4 marks or 8 marks) 2.“Outline and evaluate the nature of sleep including lifespan changes” (8 + 16) 3.“Outline lifespan changes in sleep” ( 4 marks or 8 marks)

Quiz on the nature of sleep Two minutes to look over your work

The Nature of Sleep 1.When we are awake our brain waves are of ____ __________ 2.What type of waves are characterised by the EEG in stage one? 3.What two changes begin to happen physically to the body in stage one? 4.The Hypnogogic state in stage one may involve what? 5.What waves occur in Stage 2? 6.What is a sleep spindle? 7.At what stage is if difficult to wake someone and sleep walking is most likely to occur? 8.What is released in stage 4? 9.REM or stage 5 features what type of waves? 10.Dreaming is most likely to occur at which stage? 11.Why is REM sleep known as paradoxical sleep?

Answers 1.High Frequency 2.Alpha 3.Lowering of body temperature and heartrate/Blood pressure 4.Hallucinations 5.Beta waves 6.Peak or cluster of high frequency brain waves 7.Stage 4 8.Growth hormones 9.High Frequency waves 10.REM sleep or stage 5 11.Eyes and brain are active but body in a state of paralyses

Why do we sleep? Why is sleep important? What might the approaches suggest about why we sleep?

Restoration explanation The nature of sleep allows for particular benefits, such as body repair and brain recovery For instance, the growth hormone released during the 4 th stage of sleep enables protein synthesis and cell growth to take place. This is important in the restoration of body tissue because proteins are fragile and must be constantly replaced. (Sassin et al) Similarly, REM sleep in the 5 th stage of the Basic Rest- Activity cycle enables brain recovery. Babies have approximately 50% REM sleep, whereas adult have nearer to 25% which is linked to babies’ rapid brain growth. (Siegal) This suggests that there are functions of neural development behind the nature of sleep and its stages.

Outline the nature of sleep. (8 marks) Key detail from the markscheme The nature of sleep conventionally refers to the basic characteristics of sleep. These include its circadian periodicity, the different phases and stages of sleep (REM and NREM, or REM and SWS), the association between REM sleep and dreaming etc. Different sleep patterns across the lifespan or across the animal kingdom would also be relevant. Given the problem of defining the ‘nature’ of sleep, a wide range of material could be relevant. These include the functions of sleep, sleep disorders, brain mechanisms of sleep and sleep as a biological rhythm.

Research evaluation Look at the research you have chosen for the nature of sleep Not done it? Do it Create 2 possible evaluation points for the research

The Laboratory and sleep The research in this field uses highly controlled and objective EEG scans to determine what exactly is happening in the brain which arguably provides falsifiable and empirical evidence for sleep. This tool of measurement however can make the results ungeneralisable because the setting of the research was carried out in sleep labs which although highly controlled, it is low in ecological validity because it’s different to participant’s beds and they might feel uncomfortable or experience interrupted sleep, different to the results they might show at home.

Evaluation Use the following points Discuss and evaluate the theory Individual Differences (lifespan changes/ lifestyle) Application

The Biological approach and nature (MWB) Write this IDA for the nature of sleep

Model IDA 1 The nature of sleep supports the biological approach and the nature side of the nature/nurture debate. This is because the stages are biologically determined by electrical activity in the brain. As this is a deterministic view of sleep it aids our understanding of the different stages of sleep which in turn can help us predict behaviour which may result from varying sleep patterns. It also aids our understanding of sleep disorders such as sleep walking which may lead to useful pharmaceutical treatments

Model IDA 2 The stages of sleep are biologically determined because they are caused entirely by brain activity. This is useful in terms of being able to research this area. The lack of environmental influence over the sleep stages means that we can predict, with some confidence, that they will be the same for everyone. This therefore increases the reliability of the research. Also, the emphasis on biological factors, along with the increased sophistication of brain imaging techniques, means that we can study the nature of each stage of sleep in detail thus increases the scientific validity of the research.

Model IDA 3 The research for the nature of sleep supports the biological approach and the nature side of the nature vs nurture debate. This is because the stages are biologically determined by electrical activity in the brain This is however prone to culture bias because cultural norms change across the world whereby the environment can influence sleep patterns and habits; for example the duration and timing of sleep may not be universal as Shin (2003) found that sleep duration in Korea was only 6.5 hours. This shows the differences in sleep changes are not universal and therefore this limits our understanding into lifespan changes if we take only the nature side of the nature/nurture debate.

Gender differences and sleep Research has found that more men (55%) report a better night’s sleep than women (37%) even when stressed (Kryger, 1994).

Group Task Lifespan changes and sleep Present to the group the outline and research for your group 1.Babies 2.Older Children 3.Adolescents 4.Adulthood 5.Adults 60 + Think of at least 2 reasons you can give for why sleep is occurring this way at this stage

Alternative IDA – sleep stages This research could be considered socially sensitive. This is because greater understanding of the stages of sleep and their specific functions could be useful in helping us understand and treat certain conditions that could have their roots in the deprivation of specific key stages.