BIOPSYCHOLOGY Endogenous Pacemakers, Exogenous Zeitgebers

Question 1

What are Suprachiasmatic Nucleus

Answer 1

SCN is a tiny bundle of nerves found in hypothalamus in both hemispheres

Primary endogenous pacemakers

Just above optic chiasm

Receives info about light, continues even when eyes are closed, allows biological clock to adjust to changing patterns for daylight

Question 2

Who conducted the animal study regarding endogenous pacemakers and sleep wake cycle

Answer 2

Ralph et al

Question 3

Explain the aim to the animal study

Answer 3

To investigate if transferring a SCN from one hamster will affect the sleep wake cycle in another hamster

Question 4

Explain the procedure to the animal studies

Answer 4

Bred mutant hamsters with a 20 hour sleep wake cycle

Transplanted cells from these mutant hamsters into the brains of normal hamsters

Question 5

Explain the findings of the animal studies

Answer 5

The cycles of the second group defaulted to 20 hamsters

Question 6

Explain the conclusion for the animal study

Answer 6

SCN is crucial in establishing and maintaining the circadian sleep wake cycle

Question 7

EZ influence biological rhythms : what are the events that are responsible for entraining the biological clock of an organism

Answer 7

Environmental

Question 8

What have psychologists suggested about EZ and sleep wake cycle

Answer 8

Sleeping and wakefulness appear to be determined by an interaction of internal and external factors

Question 9

What are the external factors which determine the interaction of factors

Answer 9

Light and social cues

Question 10

Who conducted a study in regards of light

Answer 10

Campbell and Murphy

Question 11

Explain the light study conducted by Campbell and Murphy

Answer 11

Found light can be detected but skin receptors even when the same information is nit detected by our eyes

Question 12

Explain the aim of the light study

Answer 12

Woke participants and shone light on back of knee

Caused deviation in their sleep wake cycle by 3 hours in some cases - because the light is triggering the internal body processes such as melatonin to stop being released

Question 13

Explain the social cues

Answer 13

Infants don’t follow same sleep wake cycle as rest of family but by 16 weeks babies are entrained to circadian rhythms

Schedules imposed by parents are key influence such as adult meal times and bed times

Research suggests that adapting to local times for eating and sleeping rather than responding to one’s own feelings or hunger and fatigue is effective way if entraining circadian rhythms