Menstrual cycle modulation of the relationship between cortisol and long-term memory.

Numerous cognitive effects of fluctuations in ovarian hormones across the menstrual cycle have been previously identified. However, the influence of ovarian hormones on learning under stressful conditions is not well understood. In this experiment, the relationship between salivary cortisol and recall performance was assessed in women at hormonally distinct phases of the menstrual cycle at encoding after cortisol levels were elevated using a cold-pressor stress (CPS) procedure. No memory difference was found between control and CPS groups in any of the three menstrual positions tested, nor was any interaction between stress condition and menstrual phase detected. However, significantly different correlations between cortisol and memory were found in the different phases. A positive correlation was found between salivary cortisol levels and recall 1 week post training when encoding occurred during the mid-luteal phase, whereas no significant relationship was found in either the early or the late follicular phase. In addition, cortisol levels were found to be elevated during the mid-luteal phase. These findings suggest that glucocorticoid effects on memory are modulated by sex hormone levels.