Biological Rhythms Flashcards
Zucker & Dark (83)
Damage so SCN disrupted circadian rhythms in squirrels.
Stephan & Zucker (72)
Damaging SCN in rats disrupts some circadian rhythms. Only 11/25 survived operation, so severity could have caused disruption.
Rusak and Zucker (75)
Circannual rhythm of testosterone in male hamsters was eliminated by SCN damage.
Abraham et al. (2000)
Melatonin injections in sparrows produce sleep.
Binkley (79)
Chickens wake up as melatonin falls.
Light = decreased melatonin.
Siffre (75)
6 months in a cave. Sleep pattern extended to 25-30 hours.
Internal mechanism, but needs zeitgebers to reset it.
Aschoff & Weber (65)
Students in a bunker. Sleep-wake cycle extended to 25-27 hours.
Russell et al. (80)
Sweat from one woman rubbed onto lips of another - menstrual cycles would synchronise.
Pheromones acted as external zeitgeber that disrupted infradian rhythm.
Coren (96)
Sleep time of 7.5 hours is 1.5 less than 100 years ago.
Coren (96)
1/5 on shift work in America.
Czeisler et al. (82)
Forwards shift rotation at Utah chemical plant. 9 months - less stress, fewer sleep and health problems, increased productivity.
Gordon et al. (86)
Forwards shift rotation in Philadelphia police. 30% less sleeping on job and 40% fewer accidents.
Phillips et al. (91)
Permanent non-rotating shift work in a Kentucky police force.
Similar results to Czeisler.
However, night shift was not popular.
Sack et al. (07)
Planned napping during shifts shown to reduce tiredness and increase performance.
Not popular with employers or employees.
Coren (96)
Rapid rotation every 2-3 days means sleep-wake cycle is not adjusted.
However, time rhythms become out of sync. Controversy over its success.
Coren (96)
Jet lag worse W-E (phase advance) than E-W (phase delay).
Recht et al. (95)
Baseball teams over 3 years. E-W won 44%, W-E won 37%.
Long enough period to cancel out other variables.
Sack et al. (07)
Jet lag decreases with age.
Coren (96)
Techniques to reduce jet lag.
Sleep before, don’t drink, adjust to zeitgebers immediately etc.
Beaumont et al. (04)
Melatonin 3 days before flight and 5 days afterwards greatly reduces jet lag.
Sack et al. (07)
Disruption of biological rhythms and sleep deprivation can reduce immune system efficiency.
Berger (29)
Synchronised and desynchronised EEG
Aserinsky and Kleitman (53) & Dement and Kleitman (57)
Used EEG to identify stages of sleep.
N1-N2-N3-REM-N2-N3-REM
REM associated with dreaming (80%) woken during REM.
Jouvet (69)
Ascending reticular formation (RF), locus coeruleus (in RF, secret noradrenaline) and raphe nuclei (in RF, secrete serotonin)