Infradian and Ultradian rhythms
Cards (11)
- Infradian rhythms - rhythms that have a duration of over 24 hours (e.g. menstrual cycle)
- Ultradian rhythms - cycles that last less than 24 hours (e.g. stages of sleep)
- Infradian rhythm
- weekly rhythms
- monthly rhythms
- annual rhythms
- Weekly rhythms
- male testosterone levels peak at the weekends
- lower frequency of births at weekends
- Monthly rhythmsMenstrual cycle 23-36 days
- governed by monthly changes in hormone levels
Research study - McClintock- menstrual cycle is an endogenous system that is affected by EZs (such as other women's pheromones)
- Annual rhythms
- birds who migrate to warmer climates/more food
- seasonal affective disorder (SAD)
- Ultradian rhythm - sleep stages
- stages 1-4 that are involved in a cycle of around 90 minutes
- some research states that it continues throughout the day (with cycles of hunger/fatigue/concentration)
- Sleep pattern research
- taking people into a different environment from one they're used when sleeping can create confounding variables that effect the results
this questions that validity and reliability of research - Russell et al
- samples of sweat from a donor were taken and rubbed onto the upper lip of women
- the groups were kept separate but their menstrual cycles synched
supports research into menstrual cycles and the EZs affects on some infradian rhythms - Methodological limitations in synchronisation studies
- there are many factors that affect a woman's cycle (e.g. stress/diet) which could act as confounding variables in synchronisation studies
this questions the validity of the results and their applicability to this area of psychology - Animal studies
- much of the knowledge of the effects of pheromones comes from animal studies which are well documented
- evidence from human behaviour is speculative and inconclusive
we can't certainly explain the effect of pheromones on humans based solely off of the questionable generalisability of animal studies