Women have sometimes reported that their memory works differently depending on which phase of the menstrual cycle they are in -- even during and following pregnancy, or following menopause, the study said.
"Our research shows that, rather than impairing memory in general, oestrogen and progesterone - female sex hormones - may instead cause the brain to favour one memory system or strategy over another," said Wayne Brake, Professor at Concordia University in Quebec, Canada.
For the study, researchers tested 45 women who had regular menstrual cycles. First, participants responded to a 'hormonal profile' questionnaire that gathered detailed information on their periods, past pregnancies, contraceptive and synthetic hormone intake history and general life habits.
The participants were then given a verbal memory task, such as remembering a list of words, as well as a virtual navigation task, such as finding their way through a maze in a video game, that could be solved in several ways.
The results showed that women who were ovulating performed better on the verbal memory task. On the other hand, women in their pre-menstrual phase tested better at solving spatial navigation tasks.
That proves that women tend to use different strategies to solve tasks -- such as navigating a maze or remembering a list of words -- depending on where they are in their menstrual cycle.
Previously studies have shown that the levels of oestrogen and progesterone in rodents influence different brain regions, affecting various memory systems involved in task-solving.
"For example, when oestrogen levels are high, female rats will use one type of memory system or strategy versus another to solve a maze. This is the first study to show that this is also true in humans (women), who solve tasks in different ways based on their hormones," Brake noted, in the paper published in the journal Psychoneuroendocrinology.
