Questions and Essay Plans

QUESTIONS AND ESSAY PLANS

1(a). Describe two biological rhythms. (9 marks)

Paragraph 1 Introduction
Describe circadian rhythms (i.e. they last 24 hours), such as the sleep–waking cycle. Identify the endogenous factors that constitute the biological clock, i.e. the SCN and pineal gland, and use research evidence as support, e.g. Siffre’s (1972) cave study and Morgan’s (1995) SCN removal and transplant studies in hamsters, and the study of the blind man by Miles et al. (1977). However, this research evidence can also be used to support the action of exogenous factors. These include zeitgebers such as light, demonstrated by Miles et al.’s (1977) study in which the blind man used zeitgebers to reduce his free-running 25-hour rhythm to the 24-hour rhythm. Also, Siffre (1972) was exposed to a dim light during his cave study. Kelly et al.’s (1999) study of the submariners and Folkard’s (1996) study of Kate Aldcroft also show the importance of exogenous factors. Biological rhythms are an interaction of nature and nurture and endogenous (internal) and exogenous (external) factors, where the endogenous factors have the strongest influence but these can be overridden.
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Describe infradian rhythms (i.e. they last longer than 24 hours), such as menstruation. Explain what this involves (a cycle of 28 days) and the role of endogenous factors, i.e. the hormones oestrogen and progesterone. Use research evidence to support exogenous factors e.g., Miles et al. (1997), and Folkard (1996). Then use research to illustrate the effect of exogenous factors, e.g. McClintock’s (1971) study and Russell et al.’s (1980) research, both of which show the effect of women’s pheromones.

1(b). Assess the consequences of disrupting biological rhythms. (16 marks)

It’s probably wise to focus on shiftwork or jet lag rather than both so you have time to achieve depth.
Paragraph 1 Introduction
Explain how shiftwork disrupts sleep patterns as found by Akerstedt (1985) and Burch et al. (2005). Consider the issue of rapid or slow rotation of shiftwork and assess the positive and negative effects of both. Use research evidence as support, e.g. Monk and Folkard (1983). Also consider the effect of phase advance/delay, i.e. it is better to rotate with the clock than against it, and the best timing for changes of shift as supported by Czeisler et al. (1982). Use Novak et al.’s (1990) research on accidents and the statistics on car accidents to support the dangers of night shiftwork.
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Consider the amount of research support and face validity of the findings. Discuss the implications of the findings in terms of direction and timing of shift changes to minimise the negative consequences. Consider the positive application of light therapy. Use methodological criticismsm, as self-report weaknesses limit validity. This means the meaningfulness and value of the research are questionable and so conclusions must be made cautiously. Also consider that the effects of disruption are subject to individual differences and correlational criticisms.

2. Discuss the role of endogenous factors in bodily rhythms. (25 marks)

Paragraph 1 Introduction
Introduce biological rhythms such as circadian and infradian. Explain what endogenous factors are, i.e. biological mechanisms (e.g. …). But there are exogenous factors that can override these.
Paragraph 2 Evidence for
Siffre’s (1972), Miles et al.’s (1977), and Morgan’s (1995) research support the role of endogenous factors in circadian rhythms. Assess the consequences of disrupting the biological clock as further evidence for endogenous factors.
Paragraph 3 Evidence against
The role of zeitgebers as demonstrated by Siffre’s (1972), Miles et al.’s (1977), Kelly et al.’s (1999), and Folkard’s (1996) research all support the role of exogenous factors and show that endogenous are not the only factors. Also shiftwork provides further evidence against endogenous factors as we can go against the biological clock, but this does have consequences.
Paragraph 4 Evidence for
The female hormones support the role of endogenous factors in menstruation. Explain the action of these hormones within the menstrual cycle.
Paragraph 5 Evidence against
Research by McClintock (1971) and Russell (1980) show the importance of exogenous factors (pheromones) in menstruation.
Paragraph 6
Conclude an interaction of internal and external control. Thus, endogenous factors alone do not account for bodily rhythms but they do have the greater influence. However, exogenous factors can override the endogenous ones and so entrain the innate rhythm, for example light entrains the free running 25-hour rhythm to the 24-hour rhythm of society.

3. Outline and evaluate theories and research studies relating to the functions of sleep. (25 marks)

Paragraph 1 Introduction
Explain that sleep is unlikely to exist unless it has a function, i.e. it is adaptive (evolutionary theory), or the function may be the restoration of physiological and psychological functions.
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Outline evolutionary/ecological theory (Meddis, 1975). Identify research evidence, e.g. research on differences in sleep patterns and duration. Also include hibernation theory (Siegel, 2005). Research findings on the fatal effects of sleep deprivation e.g. Rechtschaffen et al.’s (1983) study and Lugaressi et al.’s (1986) case study suggest that sleep is necessary for survival and so support an adaptive function. Variations in sleep patterns are evidence of adaptation to different ecological niches and thus evolutionary forces at work.
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Criticisms of Meddis (1975) are that predators often sleep longer than prey. This anomaly could be accounted for by hibernation theory as smaller animals may sleep longer to conserve energy. But does sleep conserve much energy? Also consider the vulnerability of sleep. Surely it should have been selected out when not adaptive? Thus the extraordinary lengths animals such as the Indus dolphins go to may well be due to an evolutionary function. However, the sleep patterns animals have today may be due to genome lag. Also consider the scientific criticisms, reductionism, and determinism of evolutionary explanations. However, a key limitation is that the evolutionary explanations lack explanatory power—what can they not explain? Also any nomothetic (universal) explanation is reductionist.
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Outline restoration theory including Oswald (1980), who identified NREM-body and REM-brain processes, and Horne (1988), who distinguished between core and optional sleep. Consider the research evidence for including sleep deprivation research, e.g. Randy Gardner (Gulevich et al., 1966) and Dement (1960), whose research showed the REM rebound effect and so supports the emphasis Horne placed on stage 4 and REM sleep.
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Criticise Horne’s claim that not all of REM sleep is essential using the REM rebound effect and negative effects of REM deprivation. A criticism of restoration theory is that protein synthesis has a limited time frame. Sleep deprivation research shows that activity level and sleep are not greatly related, whereas you would expect a positive correlation if restoration was the main function. Not all missed sleep needs to be recovered and the effects are more psychological than physiological. Neurochemical restoration may be a better explanation. However, REM sleep increases energy expenditure. Restoration does not account very well for the variations in sleep patterns across all species. It does have face validity and is supported by the fact we do sleep more when physically ill and patients recovering from brain trauma do spend longer in REM sleep.
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Assess the methodological criticisms of the research (e.g. researcher effects and participant reactivity, and a lack of reliability—explain these!), which means the truth/meaningfulness of the theories and research must be questioned. Conclude that both explanations may be valid and a multi-perspective is needed, for example, restoration could be the evolutionary function.

4. Discuss lifespan changes in the nature of sleep. (25 marks)

Paragraph 1 Introduction
Outline the sleep patterns of human babies and children including the fact they do not have a set pattern from birth, are prone to frequent night awakening, and the amount that babies sleep including time in REM. Use Scher’s (1991) study of night awakening as evidence.
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Consider the culture bias of Scher’s research as sleep patterns in the West may be different from those in the East and explain why this may be the case.
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Outline the changes in adult sleep patterns including the decrease in slow-wave sleep, and the consequent decrease in growth hormone, and so growth and repair of the body. Use Van Cauter et al. (2000) as evidence, and the meta-analysis of 65 studies. Introduce the stereotype of day-time naps for elderly people and the link Ancoli-Israel (2008) found between sleep and healthy ageing.
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Assess the problems of the research such as sample bias, meaning some age groups have been ignored. Foley et al.’s (2007) research is also subject to the usual correlational criticisms, including issues of direction of effect, causation, and other factors. The gender bias of single-sex studies is also an issue limiting generalisability.

5. Discuss the factors affecting insomnia. (24 marks)

Paragraph 1 Introduction
Introduce the fact that certain factors affect insomnia because they interfere with the natural progression of brain activity from daytime functioning, to slowing down, to sleeping. For example, the production of melatonin and serotonin may be affected.
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Outline environmental factors that can impair falling asleep, such as loud noises, light, heat, or cold. Explain how stress affects the autonomic nervous system. Also explain how sleep hygiene habits are linked to insomnia.
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Explain the role of obstructive sleep apnoea (OSA) and central sleep apnoea in insomnia. Give evidence for the negative effects of OSA, such as Macey et al. (2002), Kumar et al. (2008), and Goldbart et al. (2007). Evaluate the sample bias of these studies.
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Explain the role of personality in insomnia, in particular the effect of activation of the hypothalamic–pituitary–adrenal axis. Explain de Sainte Hilaire et al.’s (2005) findings on the role of serotonin. Provide evidence from Leblanc et al. (2007) and Soehner et al. (2007) on the particular personality factors associated with insomnia.
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Evaluate the key weaknesses of the research into the factors, these being linked to the correlational nature of the research, and include direction of affect, cause and effect, and reductionism of correlations.
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Consider further criticisms such as the fact that the participants in Soehner et al.’s (2007) study were not insomniacs, but normal working adults, which limits what the study can tell us about insomnia! Also consider the weaknesses of self-report and how these limit validity.