The impact of progesterone on memory consolidation of threatening images in women.

Recent findings suggest that consolidation of emotional memories is influenced by menstrual phase in women. In contrast to other phases, in the mid-luteal phase when progesterone levels are elevated, cortisol levels are increased and correlated with emotional memory. This study examined the impact of progesterone on cortisol and memory consolidation of threatening stimuli under stressful conditions. Thirty women were recruited for the high progesterone group (in the mid-luteal phase) and 26 for the low progesterone group (in non-luteal phases of the menstrual cycle). Women were shown a series of 20 neutral or threatening images followed immediately by either a stressor (cold pressor task) or control condition. Participants returned two days later for a surprise free recall test of the images and salivary cortisol responses were monitored. High progesterone levels were associated with higher baseline and stress-evoked cortisol levels, and enhanced memory of negative images when stress was received. A positive correlation was found between stress-induced cortisol levels and memory recall of threatening images. These findings suggest that progesterone mediates cortisol responses to stress and subsequently predicts memory recall for emotionally arousing stimuli.

Sex differences in emotional memory consolidation: the effect of stress-induced salivary alpha-amylase and cortisol.

This study examined sex differences in the emotional memory consolidation, and the impact of stress-induced cortisol and salivary alpha amylase responses on emotional memory recall. Following baseline salivary measures, 39 healthy women and 41 men viewed 20 neutral and 20 negative arousing images, and then underwent either a cold pressor stress test or control condition, followed by further salivary measures. Participants returned two days later for a free recall test. The stress condition induced greater cortisol response, and negative images were better recalled than neutral. Whereas women displayed greater recall of negative images under stress than men, they recalled fewer negative images in the control condition. Stress-induced cortisol predicted recall of negative images in women, and neutral images in men. This suggests there is an enhanced consolidation of negative images under stress in women that may be a potential mechanism for the greater female prevalence for developing anxiety disorders.