Infradian rhythms

Question 1

What is an infradian rhythm

Answer 1

biological rhythm with a frequency of less than one cycle in 24 hours

Question 2

What are two infradian rhythms

Answer 2

Seasonal affective disorder
Menstrual cycle

Question 3

What is seasonal affective disorder

Answer 3

depressive disorder which has a seasonal pattern of onset it is diagnosed as a mental disorder

Question 4

What are symptoms of SAD

Answer 4

persistent low mood, lack of activity and interest in life

Question 5

What triggers SAD

Answer 5

during winter months when daylight hours become shorter
SAD is affected by the exogenous zeitgebers light and dark

Question 6

Why is SAD a circannual rhythm

Answer 6

subject to a yearly cycle

Question 7

How can SAD also be classes as a circadian rhythm?

Answer 7

it may be caused due to disruptions in the sleep wake cycle due to prolonged periods of darkness in the winter

Question 8

Describe the menstrual cycle

Answer 8

-duration of more than 24hrs between 23-36 days
-its regulated by hormones and ovulation takes place halfway thru the cycle
-its is an endogenous system

Question 9

What was the aim of mcclintock and sterns study into the menstrual cycle

Answer 9

to investigate if the menstrual cycle can be influenced by exogenous zeitgebers such as femele phermones

Question 10

What was Mcclintock and sterns method

Answer 10

• sample of 29 women with a history of irregular periods
• sample of pheromones were collected from 9 women at different stages of the menstrual cycle by placing a cotton pad on their armpit which the wore for 8 hours
• pads were treated with alcohol and frozen to be rubbed on the upper lip of other ppts
• on day one pads from the start of the menstrual cycle were applied to all 20 women and on day two the were given pads from the second day etc

Question 11

What were the results of Mcclintock and sterns study into the menstrual cycle

Answer 11

68% of the women experienced changes to their cycle which brought them closer to the cycle of their odour donor

Question 12

What was the conclusion of Mcclintock and sterns study into the menstrual cycle

Answer 12

women’s menstrual cycle can be altered by communication with pheromones an exogenous zeitgeber

Question 13

What are limitations of Miclintocks and Sterns study

Answer 13

• small sample size
• correlational
• only 68% experienced changes
• metholofical issues

Question 14

Evaluate small sample size as a limitation of Mclintock and stern’s stufy

Answer 14

• small samle size of 29 women so has low population validity
• so the conclusion that menstrual cycle is altered by pheromones may not be valid as the same is unrepresentative to a wider population
• however theres no evidence that this is the case. its reasonable to argue that the small sample size is no sufficient reason to discount the findings

Question 15

Evaluate correlational as a limitation of Mclintock and stern’s study

Answer 15

• evidence is only correlational
• they haven’t procent that women’s menstrual cycle can be altered by pheromones as other factors may have been involved
• however theres still clear evidence of a correlation between exposure to exogenous factors and an alteration in menstrual cycle although evidence is limited

Question 16

Evaluate the fact that inly 68% of women showed a change as a limitation of Mclintock and stern’s stufy

Answer 16

• only 68% of the women experienced changes to their cycle which brought them closer to the cycle of their odour donor. This means that 32% didnt
• this is a limitation of their conclusions because for them to be accepted the figure must be much closer to 100%
• suggests individual differences play a role in determining the extent to which a woman’s mentrsual cycle can be altered by communication with ohermones

Question 17

Evaluate methodical issues as a limitation of Mclintock and stern’s stufy

Answer 17

• there are many factors which effect a womans menstrual cycle including stress diet etc
• these may act as confounding variables which means the pattern of synchronisation observed may be no more that what would be expected to occur by chance
• their conclusion that a woman’s menstrual cycle can be altered by communication may be invalid

Question 18

What are strengths of infradian rhythms

Answer 18

• supported by research (McClintock)
• practical applications

Question 19

Evaluate supported by research as a strength of infradian rhythms

Answer 19

• supported by research
• McClintock and stern applied pheromones obtained from 9 women to 20 ppts from day 1 of their menstrual cycle. 68% of the women experienced changes in their cycle which brought them closer to the cycle of their odour donor. Suggests women’s cycle can be altered by exogenous zeitgebers
• strength because it demonstrates how pheromones play an important part in the timing of the menstrual cycle and is objective evidence that infradian rhythms exist

Question 20

Evaluate practical applications as a strength of infradian rhythms

Answer 20

• produced effective treatment for SAD phototherapy
• this is a lightboxwhich stimulates a very strong light in the morning and evening. Its thought to-reset melatonin levels in people with SAD and relieve symptoms
• its success suggests that infradian rhythms are affected by exogenous zeitgebers such as light