AO3

• Cingulotomy


  Neurosurgical procedure involving lesioning of cingulate gyrus.
• Boivin (et al. 1996)


  Circadian rhythms - strength:

  Night workers engaged in shift work experience period of reduced concentration around 6am (circadian trough), increasing likelihood of mistakes and accidents.
• Knutsson (2003)


  Circadian rhythms - strength:

  Shift workers 3x more likely to develop heart disease.
• Baraldo (2008)


  Circadian rhythms - strength:

  Circadian rhythms have revealed certain peak times which drugs are most effective; as they coordinate main bodily processes, which has an affect on pharmokinetics. This has led to development of guidelines for timing of various drugs eg. anti-cancer, cardiovascular, respiratory, anti-ulcer, anti-epileptic.
• Czeisler (et al. 1999)


  Circadian rhythms - limitation:

  *Demonstrated poor methodology in studies of circadian rhythms eg. Siffre. Were able to adjust participants' rhythms between 22-28 hours with dim lighting; suggesting artificial light used in Siffre's study had an affect on what was being measured.

  *Individual cycles can vary from 13-65 hours.
• Duffy (et al. 2001)


  Circadian rhythms - limitation:

  Individual differences; some people are 'owls' (displaying preference for sleeping late and waking late), whilst others are larks' (preference for sleeping early and waking early).
• Monkseaton high school (+) Siffre


  Circadian rhythms - age factors as a limitation:

  Teenage circadian rhythms - found pushing the school day to start at 10am improved academic performance and health.

  Older circadian rhythms - at 60 claimed his rhythm was far slower than it had been when he was younger.

  Prevents general conclusions.
• Schank (2004)


  Infradian and ultradian rhythms - limitation of evolutionary theory:

  If too many females cycled together, would produce competition for highest quality males; avoidance of synchrony would appear to be better adaptation for real life menstrual cycle.
• Trevathan (et al. 1993)


  Infradian and ultradian rhythms - limtation:

  Stern and McClintock's research has not be replicated; no evidence for menstrual synchrony.
• Confounding variables


  Infradian and ultradian rhythms - limitation:

  many factors in Stern and McClintock's research, such as stress, diet, and exercise act as...?
• Dement and Kleitman (1957)


  Infradian and ultradian rhythms - strength:

  Research support for the significance of REM. They monitored sleep patterns of 9 adults using EEGs, found that REM activity was highly correlated with dreaming. When they were woken up during REM, participants could recall dreams very accurately. Replications have shown same findings.
• Eastman (et al. 1998)


  Infradian and ultradian rhythms - strength and limitation:

  * Phototherapy, a treatment for SAD, could improve symptoms in up to 60% of sufferers.

  *However, Placebo effect in 30% using a fake treatment called 'sham negative ion generator'.
• Kleitman (1969)


  Infradian and ultradian rhythms - strength:

  BRAC (basic rest activity cycle) theory suggests cycles during sleep occur during wakefulness; 90 mins of alertness, followed by short spell of physiological fatigue.
• Ericsson (et al. 1993)


  Infradian and ultradian rhythms - strength:

  Supports effectiveness of BRAC developed from research into ultradian rhythms. Professional/best violinists found to practice in 3 x 90 min sessions during course of day, w/ a break to recharge.
• Damiola (et al. 2000)


  Endogenous pacemakers - limitation:

  changed mice feeding patterns, found to alter circadian rhythms in liver cells by up to 12 hours. Peripheral oscillators acting independently from endogenous pacemakers (such as SCN).
• Miles (et al. 1977)


  Exogenous zeitgebers - limitation:

  Reported case of man who was blind from birth, with a circadian rhythm of 24.9hrs; unable to adjust despite social cues.
• Methodology.


  Split-brain research into hemispheric lateralisation - strength:

  Sperry's studies had highly specialised and standardised procedures; his study had good...?

  Eg. fixation point, and flashing of stimuli for 1/10th second prevents both visual fields (and therefore both hemispheres) from seeing it.
• Analyser (+) synthesiser


  Split-brain research into hemispheric lateralisation - strength:

  Sperry's research established the left hemisphere as the ... and the right hemisphere as the ...