6. BIOPSYCHOLOGY (ULTRADIAN RHYTHMS) Flashcards
What is an ultradian rhythm?
An ultradian rhythm is a biological rhythm that occurs more than once in a 24-hour period, such as the stages of sleep, which repeat approximately every 90 minutes.
How long does a typical ultradian sleep cycle last?
The typical ultradian sleep cycle lasts about 90 minutes and includes multiple stages of sleep that repeat throughout the night.
What are the five stages of sleep in the ultradian rhythm?
The five stages of sleep are:
1. Stage 1: Light sleep, easy to wake, with slowing brain waves.
2. Stage 2: Light sleep, further slowing of brain waves.
3. Stage 3: Deep sleep, difficult to wake, slower brain waves.
4. Stage 4: Deep sleep, even slower brain waves than stage 3.
5. Stage 5: REM (Rapid Eye Movement) sleep, where the brain is active, and dreaming occurs.
What happens during REM sleep?
During REM sleep, the brain is very active, resembling the awake brain. The body is paralyzed to prevent acting out dreams, and rapid eye movements occur. REM sleep is closely linked to dreaming.
What did Dement & Kleitman (1957) aim to investigate?
They aimed to investigate brain activity changes throughout night-time sleep and how this relates to different stages, particularly REM sleep and dreaming.
How did Dement & Kleitman (1957) conduct their research?
Nine participants (seven males, two females) were connected to EEG machines while they slept. They were asked to refrain from caffeine the day before the study. The EEG recorded brain activity, and participants were awakened to report dreaming during various stages.
What were the findings of Dement & Kleitman (1957)?
They found that all participants had REM sleep every night. Dream recall was higher when participants were awakened during REM sleep compared to other stages, suggesting a link between REM sleep and dreaming.
What is a limitation of Dement & Kleitman’s (1957) study?
A limitation is the small sample size (9 participants, only 2 female), which reduces population validity and may limit the generalizability of the results to the wider population.
Why is the use of EEG a strength in Dement & Kleitman’s (1957) study?
EEGs are objective and provide empirical data, which strengthens the validity of the findings by providing verifiable evidence that sleep follows a typical pattern, supporting the existence of ultradian rhythms.
How do Dement & Kleitman’s findings support the existence of ultradian rhythms?
Their study demonstrates that sleep follows a typical pattern, including regular periods of REM sleep, supporting the idea that ultradian rhythms govern the stages of sleep throughout the night.
What is a strength of the theory of ultradian rhythms in sleep?
A strength is that it is supported by research, such as Dement & Kleitman (1957), which found that all participants experienced REM sleep every night, and dream recall was most frequent during REM sleep.
How do individual differences support the biological basis of sleep cycles?
Research by Tucker et al. found large individual differences in sleep patterns, consistent over multiple nights. This suggests that sleep cycles may be biologically determined, influenced by genetics.
What did Tucker et al. (2001) find in their research on sleep patterns?
Tucker et al. found significant individual differences in sleep patterns over 11 nights, as well as different responses to sleep deprivation, suggesting that sleep cycles may be partially determined by genetic factors.
What does the finding that REM sleep is linked to dreaming suggest about ultradian rhythms?
It suggests that ultradian rhythms, such as REM sleep, play a crucial role in the psychological and physiological processes of dreaming, reinforcing the biological importance of these rhythms.
How does research on ultradian rhythms have practical implications?
Understanding ultradian rhythms, particularly the sleep cycle, can improve strategies for managing sleep disorders, shift work, and education, emphasizing the importance of REM sleep and other stages for overall well-being.
