Topic 2: Biological Rhythms: Additional Studies Flashcards
(Topic 2: Additional Studies) Describe the environments and timings of where Siffre lived during his research.
French scientist Michel Siffre lived in a cave 400 feet below the earth’s surface for 2 months in 1962. It was completely dark apart from a light bulb.
(Topic 2: Additional Studies) When did Siffre contact with a team?
Siffre was in contact with a team on the surface every time he ate, woke up and when he was going to sleep.
(Topic 2: Additional Studies) When did Siffre sleep?
He went to sleep when he wanted to & slept as long as he wanted to.
(Topic 2: Additional Studies) What did Siffre’s results show?
His body did follow a daily sleep-wake cycle but every 24 hours and 30 minutes instead of 24 hours.
(Topic 2: Additional Studies) What did Siffre’s results suggest?
This suggests that humans have an internal body clock that is independent of the natural terrestrial day/night cycle.
(Topic 2: Additional Studies) Describe the sample for Preckel et al’s study.
Studied 272 German high school children.
(Topic 2: Additional Studies) Describe the procedure for Preckel et al’s study.
Children at 5 schools were given a chronotype questionnaire (the lark-owl chronotype indicator) and a standardised cognitive test.
Parents of 132 of the students also filled in a questionnaire at home rating their child’s chronotype.
(Topic 2: Additional Studies) Describe the results of Preckel et al’s study.
It was found being an owl was a significant negative predictor of overall grade point average (GPA) after cognitive ability was controlled for.
(Topic 2: Additional Studies) Melatonin supplements: What happens in your body when light levels are low?
SCN instructs pineal gland to release melatonin (induces sleep and is inhibited by light).
(Topic 2: Additional Studies) Melatonin supplements: Describe the research (including the results) of Herxheimer and Petrie (2002).
Conducted a meta-analysis of 10 studies into effectiveness of melatonin as a jet lag treatment. Results show it is effective, particularly eastbound. Taken between 10pm and 12am and significantly reduced the effects of jet lag when crossing 5+ time zones.
(Topic 2: Additional Studies) Light box treatment: What does phototherapy reduce?
The production of melatonin therefore ticking the body into thinking it is day, and reduced drowsiness during a night shift.
(Topic 2: Additional Studies) Light box treatment: State the practical advantages of light boxes.
They are portable and effective within as little as 15 minutes.
(Topic 2: Additional Studies) Light box treatment: What did Costa et al’s (1993) conclude about bright light therapy?
That bright light therapy improved the physical fitness, sleep patterns, feelings of tiredness and performance of a group of night shift nurses compared with working under normal light.
Has a significant positive effect on shift workers.
