Infradian rhythms Flashcards
What are infradian rhythms ?
- Rhythms that have a duration greater than 24 hours
- May last days, weeks, months, years
What is the menstrual cycle ?
- Monthly changes in hormone level regarding ovulation
- Oestrogen increases to allow a mature egg to be released
- Progesterone thickens the womb lining for a period or pregnancy
- Influenced by exogenous or endogenas factors
What are examples of exogenous factors that affect the menstrual cycle ?
- diet
- weight
- exercise
- contraception
- stress
- Other women
What is Stern and McClintock’s study ?
Demonstrated how menstrual cycles may synchronise as a result of the influence of pheromones
Methods:
- 29 women with a history of irregular periods
- Samples of pheromones of 9 women via a cotton pad from the armpit
- On day 1, pads from the start of the menstrual cycle were applied under the nose of 20 women
- On day 2, the same happened and so on …..
Findings:
- Found 68% of women experienced changes to their cycle
- Bought closer to the cycle of the ‘odour donor’
- Shows period can be affected by exogenous factors
What is a strength of Stern and McClintock’s study ?
Evolutionary advantageous
- Helps with the survival of infants
- Women synced cycles to get pregnant at the same time
- In medieval times, if the women died then there was someone else to look after/ give their breast milk to
What is a limitation of Stern and McClintock’s study ?
Confounding variables
- Other exogenous factors were not controlled
- E.g stress and diet
What is a supporting study of Penton-Volk ?
Method: Made women rank pictures of men from most attractive to least attractive
Results: Most feminine face linked to least fertile
Most masculine face was linked to most fertile
Shows that Menstrual cycle can affected power of attraction
What does SAD stand for ?
Seasonal affective disorder
What is SAD ?
- A depressive disorder which has a seasonal pattern
- Diagnosed and described as a mental disorder
- Symptoms are triggered in the winter as daylight orders are shorter
- SAD is also known as a circannnual rhythm (specific infradian rhythm) due to it’s yearly cycle
What are the main symptoms of SAD ?
- persistent low mood
- lack of activity
- lack of intrest in life
What causes seasonal depression ?
- Due to the lack of light, the secretion of melatonin by the pineal gland takes longer
- This has a knock on effect to the production of serotonin
- An serotonin has been linked to depressive symptoms
