Females' menstrual cycle and incentive salience: Insights on neural reaction towards erotic pictures and effects of gonadal hormones.

Background: Studies in regard to womens' neural reactivity to erotic and other positive emotional cues in association with sexual hormones are relatively rare and findings rather inconclusive. Concerning the neural reactions towards erotic stimuli, the late positive potential (LPP) is seen as the most relevant ERP-component: More positive amplitudes are supposed to reflect larger motivational salience and higher arousal in reaction to the presented stimuli. Therefore, it was expected that the LPP in reaction to erotic pictures would be more pronounced during fertile periods of the menstrual cycle around ovulation, as well as to be associated with estradiol-levels. A similar pattern was hypothesized to be present with testosterone-levels, whereas no association with progesterone was expected. Method: N ​= ​35 free-cycling women completed an Erotic picture Stroop task (neutral, positive, and erotic stimuli, with three neutral- and three erotic subcategories) during follicular phase, ovulation and luteal phase, while EEG was recorded. Subjects provided saliva samples in order to determine estradiol-, progesterone-, and testosterone levels at each measuring time, and affective states were assessed using the Positive and Negative Affect Scale (PANAS). Results: LPPs in reaction to erotic-compared to positive- and neutral pictures were larger in every cycle phase. LPPs in reaction to erotic couples were strongest in comparison to every other (sub-) category. During ovulation, higher estradiol-concentrations were associated with lower LPP-amplitudes towards erotic-couples- than to neutral pictures. No effects of progesterone, no direct effect of testosterone, as well as no effects of cycle phase, were evident. Conclusion: Results partly contradict our hypotheses, as estradiol was expected to be positively associated with LPP during fertile stages. Possible differences between stimulus-entities (words v. pictures) and ideas for further research are being discussed.