Biopsychology: Circadian Rhythms Flashcards
what’s a biological rhythm?
distinct patterns of changes in body activity that conforms to a cyclical time period. biological rhythms are influenced by internal body clocks (endogenous pacemakers) and external factors (exogenous zeitgebers).
what’s a circadian rhythm?
a type of biological rhythm, subject to a 24 hour cycle, which regulates a number of body processes such as the sleep/wake cycle and changes to core body tempurature.
what’s Siffre’s cave study?
he spent several extended periods underground to study the effects on his own biological rhythm. deprived of natural ligth and sound, but still had food and water. He resurfaced in September 1962 after 2 months of being in a cave, believing it was mid August. His biological rhythm was just beyond 24 hours.
what was Aschoff and Wever’s study?
they convince a group of participants to spend 4 weeks in a WW2 bunker deprived on natural light. all but 1 participant displayed sleep/wake cycles between 24 and 25 hours. both experiments shows the natural sleep/wake cycle is slightly longer than 24 hours.
what was Folkard’s study on circadian rhythms?
he studied a group of 12 people who agreed to live in a dark cave for 3 weeks, retiring to bed when the clock said 11:45pm and rise at 7:45am. over the course of the study, the researchers gradually sped up the clocks so an apparant 24 hour cycle was actually 22 hours. only 1 of the participants comfortably adjusted, suggesting circadian rhythms can’t be adjusted easily.
what’s the practical application of circadian rhythms? (A03)
it’s given a better understanding of the consequences of disruption of sleep/wake cycle to night workers. they experience a period of reduced concentration at around 6am meaning accidents/mistakes are more likely to happen. there’s also evidence of a relationship between shift work and poor health: 3 times more likely to develop heart disease due to the stress of adjusting to different sleep/wake cycles and poor quality sleep during the day.
what’s the practical application to drug treatments? (A03)
circadian rhythms co-ordinate with a number of body’s processes: heart rate, digestion and hormone levels. this has an effect on pharmacokinetics (action of drugs and how well they absorb/distribute). research reveals there are certain peak times where drugs would be most effective. this led to development of guidelines to do with timing of drug dosing.
how is the use of case studies and small samples a limitation? (A03)
studies into sleep/wake cycles tend to involve small samples of particpants: Siffre’s case study or Aschoff and Wever sample. the people involved may not be representative of the whole population, meaning it can’t be generalised. Siffre observed, at age 60, his internal body clock ticked much slower than when he was younger. even when it’s the same person, there are factors involved.
