An examination of three aspects of cognition across two menstrual cycles found that the levels of estrogen, progesterone and testosterone had no impact on working memory, cognitive bias or ability to pay attention to two things at once.
While some hormones were associated with changes across one cycle in some of the women taking part, these effects didn't repeat in the following cycle. Overall, none of the hormones the team studied had any replicable, consistent effect on study participants' cognition.
The team, working from the Medical School Hannover and University Hospital Zürich, recruited 68 women to undergo detailed monitoring to investigate changes in three selected cognitive processes at different stages in the menstrual cycle. While analysis of the results from the first cycle suggested that cognitive bias and attention were affected, these results weren't replicated in the second cycle. The team looked for differences in performance between individuals and changes in individuals' performance over time, and found none.
Professor Brigitte Leeners , team lead, said, "As a specialist in reproductive medicine and a psychotherapist, I deal with many women who have the impression that the menstrual cycle influences their well-being and cognitive performance."
But at least in this small study it was shown that there is difference that can't be attributed to normal statistical variation.