Social attention, memory, and memory-guided orienting change across the menstrual cycle.

Numerous studies have shown that perception of emotion and emotional memory vary across the menstrual cycle. However, most of these studies used stimuli that contained not only emotional but also social elements. Importantly, the social cognitive abilities of individuals are as crucial as emotional abilities for danger avoidance and recruitment of allies. Therefore, the issue that natural hormonal fluctuations may affect emotion processing should be revisited. To investigate whether the effects of the menstrual cycle are emotion-specific or can also be attributed to social information processing, the present study examined social attention across the menstrual cycle in three tasks-visual search, memory, and memory-guided orienting-with a combination of behavioral and eye-tracking measures. We used images of people standing upright with neutral emotion as social distractors and everyday objects with physical properties matched as non-social distractors. Thirty-six healthy women without hormone use and with stable menstrual cycles of 26 - 30 days participated in the three tasks in the late follicular phase (FP) and mid-luteal phase (LP), respectively. During visual search, participants were asked to search for targets accompanied by social or non-social distractors in complex scenes. Social attentional bias, as evidenced by longer search times and shorter gaze behaviors for targets with social distractors, was found in the FP but not in the LP. In the following memory task, memory accuracy for targets was higher in the FP than in the LP, and the memory for targets with social distractors was more precise in both phases. Finally, in the orienting task, targets in social scenes were detected more slowly than in non-social scenes in LP. Taken together, these findings point to the interplay between social attention, memory, and memory-oriented attention and reveal the distinct processing pathways for social information in the FP and LP. The underlying mechanisms from an evolutionary perspective and from behavioral and neural basis were discussed.