BIOPSYCH ( Infradian and Ultradian rhythms)

Question 1

Outline Infradian rhythms and state an example

Answer 1

Infradian rhythm have a duration of over 24hrs may be weekly, monthly or even annually. An example of this is the menstrual cycle . It is regulated by hormones , which either promote circulation or stimulate the uterus for fertilisation

Question 2

Define the Ultradian rhythm and state an example

Answer 2

Ultradian cycle lasts less than 24hrs such as the sleep cycle recovering throughout the night in 90 minute durations. A complete sleep cycle consists of a progression through the 4 stages of Non-REM before entering REM

Question 3

Evaluate the Infradian Rhythms

Answer 3

One limit is methodological limitations. Sychronity of periods could be put down to chance . Researchers found that the model explaining periods by chance was by far the best.

This is supported by study into 186 Chinese women who lived together in a dorm . Menstrual cycle data was collected and found that group synchrony was at the level of chance.

However McClintok found 68% experienced changes to cycle to be closer to odour donor. Although this reasearch was flawed.

Question 4

Evaluate the research into Ultradian cycles

Answer 4

Supporting research includes researchers monitoring 9 ppts in a sleep lab .REM activity was highly correlated with dreaming . The REM stage appears to be necessary for people to reap benefits of the increased plasticity they exhibit during NREM sleep.

HOWEVER individual differences in sleep cycles could also be determined by bio or even genetic factors. ppts spent 11 days in a controlled lab . Sleep duration , time to fall asleep ad amount of time in each stage was measured .

Found large individual differences in these characteristics which showed up across the time of the study . Differences at stage 4 and 5 were particularly significant