Key Studies on Sleep and Insomnia

What was the main method used by Stephan and Zucker to investigate circadian rhythms?

• Case study of a human participant

• Lab experiment on rats with SCN lesions

• Longitudinal study

• Natural observation

What was the key finding of Stephan and Zucker's study?

• Rats' circadian rhythms are unaffected by SCN damage.

• SCN damage eliminated normal circadian patterns of drinking and activity in rats.

• Light exposure is more important than the SCN in regulating rhythms.

• Circadian rhythms improved after the SCN was removed.

What method did Siffre use to study biological rhythms?

• MRI scanning of brain activity during sleep

• A controlled case study in an underground cave

• Laboratory-based experiment using sleep monitoring

• Cross-sectional study with multiple participants

What was a key finding from Siffre's study?

• His sleep/wake cycle extended to 25-32 hours without external light.

• His body temperature and circadian rhythm desynchronized completely.

• His days became shorter, returning to a 20-hour cycle.

• External light had no effect on circadian rhythms.

What variable did Horne and Pettitt manipulate in their study on sleep deprivation?

• Duration of sleep deprivation (24 hours vs. 48 hours)

• Financial incentives given during sleep deprivation

• Amount of light exposure during sleep deprivation

• Quality of sleep participants received

What did Horne and Pettitt conclude about the effects of sleep deprivation?

• Cognitive performance improves after sleep deprivation.

• Motivation, not cognition, is initially affected by sleep deprivation.

• All sleep is necessary for normal functioning.

• Recovery from sleep deprivation takes weeks.

What method was used in Gregory et al.'s study on family conflict and insomnia?

• Cross-sectional survey

• Laboratory-based experiment

• Longitudinal study using questionnaires

• Case-control study

What did Gregory et al. find about the relationship between family conflict and insomnia?

• No relationship was found.

• Family conflict at age 9 was correlated with insomnia at age 18.

• Family conflict caused insomnia directly.

• Socioeconomic status was the only predictor of insomnia.

Which variable was positively correlated with the amount of REM sleep in Lesku et al.'s study?

• Body mass

• Brain mass

• Sleep exposure index

• Trophic position

What did Lesku et al. conclude about sleep exposure index?

• Herbivores sleep more than carnivores.

• More dangerous sleeping sites reduce REM sleep.

• Basal metabolic rate predicts REM sleep.

• Sleep exposure index has no impact on sleep patterns.