infradian + ultradian rhythms

Question 1

what are infradian rhythms

Answer 1

take longer than 24 hours to complete e.g. menstruation, SAD

Question 2

what are ultradian rhythms

Answer 2

take less than 24 hours to complete e.g. stages of sleep

Question 3

what is the AO1 for infradian rhythms - the menstrual cycle

Answer 3

• Monthly changes in hormone levels regulate menstruation.
• The cycle runs from the first day of the
  woman’s period, where the lining of the womb is shed, to the day before her next period.
• The average cycle is 28 days (ranging from 24-35 in most women)
• During each cycle, rising levels of the hormone OESTROGEN cause the ovary to develop an egg and then release it (ovulation- around day 14).
• After ovulation, the hormone PROGESTERONE helps the womb lining to grow thicker, preparing it for a fertilised egg to embed there (pregnancy).
• If pregnancy does not occur, the lining of the womb falls away and the woman experiences her period.

Question 4

what are the AO3 points for infradian rhythms - the menstrual cycle

Answer 4

• Infradian Rhythms and Exogeneous Zeitgerbers
• Research into changing Infradian Rhythms
• Menstrual Cycle and Mate Choice

Question 5

expand on the +ve AO3 point, Infradian Rhythms and Exogeneous Zeitgerbers

Answer 5

• Reinberg (1967) examined a woman who spent three months in a cave with only a small lamp to provide light.
• Reinberg noted that her menstrual cycle shortened from the usual 28 days to 25.7 days.
• This result suggests that the lack of light in the cave affected her menstrual cycle, and therefore this suggests that the menstrual cycle is, to some extent, governed by exogenous zeitgebers

Question 6

expand on the +ve AO3 point Research into changing Infradian Rhythms

Answer 6

• Stern and McClintock (1998) demonstrated that one woman’s menstrual cycle can synchronise with other women’s as a result of the presence of PHEROMONES.
• Sample- 29 women with a history of irregular periods.
• 9 women collected “pheromone samples” by wearing a cotton pad under their armpit for over 8 hours.
• The pads were treated with alcohol and frozen.
• They were rubbed on the upper lip of the other 20 participants.
• The result was that 68% of the women fell into a menstrual cycle in line with their “odour donor”.
• This has been explained by evolutionary psychologists as being an ADAPTIVE RESPONSE which has evolved because it would have been beneficial for our female ancestors to fall pregnant together, and help each other through pregnancy, birth and early motherhood (collective breast-feeding etc).

Question 7

expand on the +ve AO3 point, Menstrual Cycle and Mate Choice

Answer 7

• Penton Voak suggests that human mate preferences vary according to the menstrual cycle (infradian rhythms).
  Female pps were shown faces on a computer screen and were able to masculinise them or feminise them at a touch of a button.
• Findings showed that when the women were at their most fertile (during ovulation) they preferred faces with really masculine features, and at other points on the cycle, a more feminised version (softer) of the male face.
• Psychologists suggest that this is because unconsciously we are choosing “good genes” for our children during our most fertile period, but we want kind, caring fathers who stick around in the long-term. This is an EVOLUTIONARY EXPLANATION because it gives humans an ADAPTIVE ADVANTAGE!

Question 8

what is the AO1 for Seasonal Affective Disorder (SAD)

Answer 8

• SAD is a depressive disorder which affects people during the Winter months when there are greater hours of darkness.
• It is thought that the hormone MELATONIN is responsible for SAD, because the long hours of darkness mean increased amounts of melatonin are produced and this is thought to disrupt serotonin levels in the brain, causing the depressive feelings.

Question 9

what is the -ve AO3 Controversial Infradian Rhythms- Phases of the moon!

Answer 9

• Despite empirical evidence to the contrary, if you speak to various members of society, particularly midwives, police officers, and psychiatric nurses, they will swear blind that a full moon has a huge effect on human behaviour.
• SOME correlational studies exist but certainly none that have discovered a CAUSAL relationship.

Question 10

what is the AO1 for ultradian rhythms

Answer 10

• There are five stages that make up a typical night’s sleep:
• This cycle lasts between 90-100 minutes and occurs over and over again throughout the night.
• Stage 1-4 are NON REM, stage 5 is REM
• Each stage shows a distinct EEG pattern.

Question 11

what is the AO3 Evidence for Stages of Sleep

Answer 11

• Dement and Kleitman (1957) monitored the sleep patterns of 9 pps in a sleep lab.
• Brainwave activity was recorded on an EEG and the study was highly controlled (no alcohol, caffeine etc) to eliminate confounding or extraneous variables.
• REM activity during sleep was highly correlated with the experience of dreaming, brain activity varied according to how vivid dreams were and pps woken during stage 5 gave detailed reports of their dreams.
• These findings have been replicated by many other psychologists and are therefore reliable.

Question 12

what is the AO1 The BRAC- Basic Rest Activity Cycle

Answer 12

• Kleitman (1969) believed that this cycle continues throughout the day when we are awake- so that every 90 minutes we go through periods of alertness through to fatigue.
• Research suggests that the human mind loses focus after 90 minutes and cannot regain focus until after a rest or change in action/behaviour.

Question 13

what is the AO3 Research Support for BRAC

Answer 13

• Ericsson et al (2006) studied a group of elite violinists and found that practise sessions were limited to 90 mins at a time, with practise distributed during the day in 90 minute segments.The violinists frequently napped to recover from a 90 minute practise session
• The same pattern was discovered among other musicians, athletes, chess players and writers.