Effects of the menstrual cycle on working memory: comparison of postmenstrual and premenstrual phases.

This study aimed to examine the effects on working memory of the postmenstrual and premenstrual phases. The subjects were 12 female students. Computer-based tasks formulated by the authors, using the working memory that actively retains the information as the index, were used for experiments of 60 min during the premenstrual and postmenstrual phases. Session order was counter-balanced. The results showed that there was a significantly lower error rate for working memory tasks in the premenstrual phase, suggesting that task performance was good. Mild premenstrual symptoms had no effect on working memory function of the premenstrual phase. Further, no clear difference in terms of phase was found for mental workload or change in heart rate variability, which are used to evaluate workload. For this reason, the estrogen sex hormone secreted from the ovaries in relation to the menstrual cycle is thought to be involved in the working memory function rather than the indefinite menstrual complaint.