EVALS Rhythms

• EVALS - CR

  • S - R into CR - support for light as a pacemaker
  • S - R into CR - evidence that individual differences are bio determined
• EVAL - UR

  • s - R into UR - evidence for stages of sleep
• EVALS - IR

  • S - support for the role of exogenous cues
  • w - R into IR - problems with synchronisation studies
• S - IR - support for the role of exogenous cues. Russell et all collected samples of sweat from a group of women and applied it to the upper lip of a 2nd group of women. Even though women were kept separate, found the menstrual cycle of women in the 2nd group synchronised with the women who was the odour donor. S bc - shows our understanding of IR being influenced by bio chemicals like pheromones is accurate. Shown by women whose cycles shift when exposed to pheromones and since pheromones are bio chemicals like hormones, we can infer that IR are bio determined. Increase V
• W - R into IR - problem with synchronisation studies. Critics of this R have argued that there are many factors that may influence the menstrual cycle e.g. diet, stress, exercise. These factors act as EVs so we Q the C+E rs between pheromones and the menstrual cycle. Also, the R used small samples of women and therefore might not be generalisable to the wider population. They all also rely on self report of the onset of cycles and the recollection may be inaccurate. finally, Trevathan et al failed to find evidence of menstrual sychrony. w with the supporting evidence undermine the v of IR
• S - R into CR - support for light as a pacemaker. Hughes tested hormone release in 4 Ps at an Antarctic station and found that in Feb (summer) cortisol levels were highest when Ps were waking up, and lowest as they were about to go sleep. But after 3 months of darkness and changes in daylight patterns, cortisol release changed to and peaked at afternoon instead. Shows the role of light in CR as it demonstrates that changes in the daylight can cause changes in CR and the hormone release cycle. Adds V to our understanding or CR and what causes them
• S - R into CR - evidence that individual diffs are bio determined. Diffs in the sleep patterns of individuals are usually blamed on situational factors such as room temp. Tucker et a studied Ps over 11 consecutive days + nights in a strictly controlled lab environment. Rs assessed sleep duration, time to fall asleep + the amount of time in each sleep stage. Found ...
• (S - CR - individual diffs bio determined - Tucker et al)... Found large individual diffs in characteristics such as sleep duration + time to fall asleep remained consistent over time. Shows changes in sleep conditions didn't lead to changes in sleep patterns. Seems that sleep habits are bio determined rather than driven by external factors. V CR
• S - R into UR - evidence for stages of sleep. Dement and Kleitman monitored sleep patterns of nine adults in a lab through brainwave activity recorded on an EEG. Rs also controlled for the effects of caffeine and alcohol. Found that REM activity correlated with dreaming and a specific pattern of brain activity. This shows that our understanding of the sleep cycle and what occurs in the stages of sleep is accurate. Bc it demonstrates that REM sleep is eliciting dreaming and it's own pattern of brain activity. Thus validating our understanding of UR