We all have that one colleague or friend who cries "period!" when they do something stupid or miss a deadline, but is there any evidence for this menstruation myth?

A top reproductive specialist says it's long been assumed that women aren't operating at top mental pitch during their period, but Professor Brigitte Leeners and her team of researchers have found evidence to suggest that's actually not the case. New findings, published yesterday in Frontiers in Behavioural Neuroscience, are set to change the way we think about our periods. Professor Leeners and her team from the Medical School Hannover and University Hospital Zürich, examined three aspects of cognition across two menstrual cycles, and found that the levels of oestrogen, progesterone and testosterone in women's systems have no impact on their working memory, cognitive bias or ability to pay attention to two things at once. The top specialist says that, 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 women's brain function:

"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. The hormonal changes related to the menstrual cycle do not show any association with cognitive performance. Although there might be individual exceptions, women's cognitive performance is in general not disturbed by hormonal changes occurring with the menstrual cycle."

However, the professor cautions that there's more work to do when it comes to understanding how our periods affect our brains:

"While this study represents a meaningful step forward, larger samples, bigger subsamples of women with hormone disorders, and further cognitive tests would provide a fuller picture of the way that the menstrual cycle affects the brain."

In the meantime, Leeners hopes her team's work will start the long process of changing society's mindset about menstruation.