OxfordAQA International A Level Psychology 3.3.1 Psychology of Sleep Exam Questions

About OxfordAQA International A Level Psychology 3.3.1 Psychology of Sleep

Psychology of sleep is the first section of Unit 3, Advanced topics and research methods 2, on the OxfordAQA International A2 Psychology course. You study biological rhythms, including circadian, infradian and ultradian rhythms, and how endogenous pacemakers such as the suprachiasmatic nucleus and exogenous zeitgebers such as light control the sleep/wake cycle. You look at the effects of shift work and jet lag, the nature of non-REM and REM sleep, and three explanations for why we sleep: evolutionary explanations, restoration theory and memory consolidation. Finally you study the sleep disorders insomnia, including personality and genetic factors, and narcolepsy. Examiners ask you to describe and evaluate theories using research evidence.

What you need to know

• Biological rhythms Circadian rhythms last about 24 hours, such as the sleep/wake cycle. Infradian rhythms last longer than a day, such as the menstrual cycle. Ultradian rhythms are shorter than a day, such as the roughly 90 minute cycle of sleep stages.
• Pacemakers and zeitgebers The suprachiasmatic nucleus (SCN) in the hypothalamus is the main endogenous pacemaker; it receives light information from the eyes and influences melatonin release from the pineal gland. Ralph et al. (1990) transplanted SCN cells between hamsters and the recipients took on the donors' rhythms. Siffre's cave studies showed the free-running cycle is slightly longer than 24 hours without zeitgebers.
• Shift work and jet lag Shift work and jet lag cause desynchronisation between internal rhythms and external cues, leading to fatigue, poorer concentration and health risks. Travelling east, which shortens the day, is usually harder to adjust to than travelling west.
• Nature of sleep Non-REM sleep includes lighter stages and deep slow-wave sleep with delta waves. REM sleep has rapid eye movements, brain activity similar to waking and muscle paralysis, and is linked to vivid dreaming (Dement and Kleitman, 1957).
• Functions of sleep Evolutionary explanations (for example Meddis) suggest sleep keeps animals safe and conserves energy when activity is risky. Oswald's restoration theory proposes slow-wave sleep restores the body and REM sleep restores the brain. Memory consolidation theory suggests sleep strengthens memories; Jenkins and Dallenbach (1924) found better recall after sleep than after the same time awake.
• Sleep disorders Insomnia is difficulty falling or staying asleep; personality factors such as anxiety and a tendency to worry, and genetic factors shown in twin and family studies, may contribute. Narcolepsy involves excessive daytime sleepiness and sudden sleep attacks, often with cataplexy, and is linked to a loss of hypocretin (orexin) neurons in the hypothalamus.

Common mistakes in 3.3.1 Psychology of Sleep

• Confusing infradian and ultradian rhythms. Infradian rhythms last longer than a day; ultradian rhythms are shorter.
• Describing the SCN as the only influence on the sleep/wake cycle. Exogenous zeitgebers such as light and social cues reset it daily.
• Saying REM sleep is deep sleep. Deep sleep is slow-wave non-REM sleep; REM brain activity resembles waking.
• Evaluating theories of sleep without evidence. Use studies of sleep deprivation, differences between species and memory research.
• Treating insomnia as having one cause. Explanations combine personality, genetic and environmental factors.

Try three 3.3.1 Psychology of Sleep exam-style questions