Biopsychology - infradian and ultraradian rhythms Flashcards
what are infradian rhythms
frequency of less than 1 cycle in 24 hours
how the menstrual cycle synchronised
Stern and McClintock (1998)
- 29 women with a history of irregular periods
- samples of pheromones gathered via a cotton placed under their armpit
- pads rubbed on upper lip of other pps
- 68% experienced changes
what is seasonal affective disorder
- melatonin is involved
- at night the pineal gland secretes melatonin until dawn where there is an increase in light
- in winter the serotonin process continues for longer - knock on effect on serotonin in the brain linking to depression
what is the strength of Infradian rhythms
- may be explained by natural selection
- synchronisation may have some evolutionary value
- for ancestors may have been advantageous for women to be pregnant at the same time - help of other mothers
Real World application
- light therapies can reduce effects of SAD in 80% of people
what is the limitation of infradian rhythm
- many factors that may affect the menstrual cycle
- confounding variables
- findings may occur by chance
what are ultradian rhythms
frequency of more than one cycle in 24 hours
- sleep cycle
what are the stages of sleep
Stages 1+2
- light sleep and easily woken
- alpha waves
Stages 3+4
- deep sleep
- delta waves
- more difficult to wake someone
Stage 5 -REM
- rapid eye movement
- occurrence of dreams
- body is paralysed but the brain is awake
what is the strength of ultradian rhythms
- improved understanding of age related sleep
- growth hormone produced more in deep sleep and reduced in older people
- to increase deep sleep medication and meditation may be used
what is the limitation of ultradian rhythms
Tucker et al (2007)
- found large differences between participants in terms of duration of each sleep stage
