Biological Rhythms - The Ultradian Rhythm

Question 1

Ultradian Rhythms

Question 2

Examples of Ultradian Rhythms

Question 4

Strength

Answer 4

Point: Research suggests that ultradian rhythms, particularly the sleep cycle, demonstrate a high degree of flexibility in response to sleep deprivation.

Evidence: A case study by Randy Gardner showed that, despite staying awake for 264 hours, he was able to recover only part of his lost sleep. After this experience, Randy slept for just 15 hours and over several nights he recovered only 25% of his lost sleep. Interestingly, he recovered 70% of Stage 4 sleep, 50% of his REM sleep, and very little of the other stages. Furthermore, whilst he experienced numerous problems such as blurred vision and disorganised speech, he coped rather well with the massive sleep loss. This suggests that the body prioritises certain sleep stages over others, rather than making up all lost sleep equally.

Justification: These findings indicate that the sleep cycle is not rigid, as the body can adapt and compensate for extreme sleep deprivation by selectively recovering the most essential sleep stages. This challenges the idea that a fixed amount of sleep is needed every night and instead supports the notion that sleep operates on a flexible, homeostatic process.

Implication: Understanding the adaptive nature of ultradian rhythms has important applications in areas such as sleep therapy and shift work management, as it suggests that not all sleep is equally important. This could influence clinical treatments for sleep disorders by focusing on maximising restorative sleep stages, rather than simply increasing overall sleep duration.