Biopsychology- Infradian and Ultradian rhythms

Question 1

Infradian rhythm definition

Answer 1

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

Question 2

Example of Infradian rhythm

Answer 2

Menstrual cycle

Question 3

What exogenous factors affect menstural cycle

Answer 3

Stress, diet, light

Question 4

A03- research support for Infradian rhythms (R)

Answer 4

Reinburg (1967)
-woman 3 months in cave
-small light from lamp
-days lengthened to 24.9 hrs
-mensural cycle shortened to 25.7 days

-light is important factor in determining Infradian cycles

Question 5

Counter argument for Reinburg

Answer 5

-lacks population validity (1 person)
-lacks generalisability
-varies between people, not everyone is the same
-focused on males (would affected in same way?)

Question 6

A03- research support for Infradian rhythms (M)

Answer 6

McClintok
-pheromones collected from 9 women different stages of menstrual cycle
-cotton pads in armpit then alcohol and frozen
-rubbed on upper lip of other ppts
-68% women experienced changes to their cycle which bought them closer to the odour donor

-suggests synchronisation of menstrual cycles can be affected my pheromones, exogenous factor

Question 7

Counter argument for McClintok

Answer 7

Lack validity
- unable to control other factors eg. Stress, diet
-lack of control of extraneous variables; cause and effect hard

• confounding factor- natural variation with amount of time females spend together

Question 8

Ultradian rhythms definition

Answer 8

Lasts longer than 24 hours can be found in pattern of human sleep

Question 9

What are the stages of sleep

Answer 9

Stage 1: very short, theta waves, nodding off
Stage 2: 20 mins, sleep spindles, easily woken
Stage 3: 15 minutes, brain waves slow, delta waves deep sleep
Stage 4: 40 minutes, delta waves, heart rate, blood pressure fall, low temp, growth hormones released
Then…
Go back through 3 and 2
Then…
Stage 5: REM sleep: very active, brain activity like awake, dreams, muscles temporality paralysed, heart rate increases etc
Go back through 4,3,2
Wake up

Question 10

A03- research support for ultradian rhythms

Answer 10

Dement and Kleitman
-monitored sleep patterns 9 ppts
-recorded on EEG
-woken by doorbell, asked to describe dream then sleep again
-either woken in REM or nREM sleep

-described dreams more in REM sleep than nREM sleep
-woken in nREM returned to nREM but woken in REM didn’t return to dream till next REM

-SUPPORTS IDEA STAGES BEING CYCLICAL IN NATURE

Question 11

Counter point for Dement and Kleitman

Answer 11

Many ppts didn’t report dreams in REM, some reported outside of REM sleep
- goes against idea rem sleep associated with dreams, not everyone having same experience, individual differences when dreaming

Question 12

A03- mythological issues with Ultradian rhythms study of slee

Answer 12

-sleep labs using EEG- electrodes and hooked up to monitor
-will disrupts normal sleeping patterns
-may lack validity