The relationship between menstrual cycle changes in nervous system activity and psychological, behavioural and...

The present study (N = 30) investigated the relationship between menstrual cycle changes in nervous system activity and in psychological, behavioural and physical variables. Two-flash fusion, electrodermal activity and questionnaire measures were used. Each participant was tested in the premenstrual phase (PM) and in the middle third of the cycle (MC). PM cortical alertness was low, and these low levels were related to high levels of negative psychological change. PM autonomic (electrodermal) reactivity, though high, was not directly related to other variables; electrodermal resting level was negatively related to some physical and behavioural variables. PM self-reported perception of autonomic activity was significantly related to negative mood. MC cortical alertness was high. Self-reported levels of cortical and of autonomic activity were related negatively and positively respectively to negative states. It is suggested that certain aspects of nervous system activity, in combination with individual perceptions of reactivity, are significant intermediary mechanisms in some of the reported manifestations of the cycle.