Endogenous PM, Exogenus ZTGB On Sleep Wake/Circadian Rhythm

Question 1

Strength: RTS DECOURSEY ET AL

Answer 1

destroyed SCN connections in brains of 30 chipmunks, returned to natural habitat and observed for 80 days, sleep wake cycle disappeared, end of research significant proportion killed by predators, were awake and vulnerable to attack when should be asleep, supports influence & importance of endogenous p (SCN) on maintenance of sleep wake as EX ZEGB not alone able to maintain, inc Val research

Question 2

Discussion: weakness of study animal bias

Answer 2

humans may have more complex interaction between endogenous pacemakers and exogenous zeitgebers as greater number of zeitgebers that can influence human rhythms (social interaction, clocks) compared to animals instinctive response to limited environment factors, issues with extrapolating the findings to humans, limits the extent of support

Question 3

Strength: RTS MICHEL SIFFRE

Answer 3

Lived in a cave isolated from exogenous zeitgebers (clocks, light dark cycle) for 6 months, within a few days developed consistent 25 hour cycle, fall asleep and wake up on regular schedule, sleep wake controlled by endogenous as siffre developed consistent rhythm w o external cues, so primarily governed by EP, inc validity of research (some may argue that bc 25 hr cycle EZ needed to maintain sleep wake)

Question 4

Weakness: SIFFRE lacks ecological validity

Answer 4

Living conditions highly controlled, not reflect how EP and EZ interact in real life, only exceptional circumstance