Fluctuations of estradiol during women’s menstrual cycle: Influences on reactivity towards erotic stimuli in the late positive potential

•Associations of LPP-amplitudes in reaction to erotic words with estradiol concentrations in free cycling women.•Estradiol concentrations correlate positively with LPP-amplitudes towards erotic words during follicular phase & ovulation.•Progesterone is not associated with the reactivity towards erotic words in the LPP.•During luteal phase, estradiol-concentrations are not associated with LPP-amplitudes towards erotic (vs. neutral) words.•Cycle phase is not associated with the reactivity towards erotic words in the LPP. While several studies examined the reactivity towards negative emotional stimuli across women’s menstrual cycle, only few investigated responses to positive emotional cues in association with sexual hormones on a neural level. Therefore, the aim of the current EEG-experiment was to study the differential reactivity towards positive (erotic) words during the menstrual cycle (i.e. with fluctuations in the steroids estradiol and progesterone) in the late positive potential (LPP). Regarding reactivity towards erotic stimuli, the LPP is seen as the most relevant ERP-component, as more positive amplitudes in the LPP reflect larger incentive salience and higher arousal. The LPP towards erotic words was expected to be more pronounced during fertile phases of the menstrual cycle (around ovulation). Furthermore, associations with hormonal concentrations of estradiol and progesterone were investigated. 19 young, free cycling women were tested in an Erotic Stroop paradigm during the follicular phase, ovulation, and the luteal phase in a balanced cross-over design, while electroencephalogram (EEG) was recorded. LPPs in reaction to erotic compared to neutral words were larger in every phase. During the follicular phase and ovulation, higher estradiol-concentrations were associated with more positive LPP-amplitudes towards erotic- than to neutral words. No effects of progesterone, as well as no effects of cycle phase, were evident. Results are being discussed regarding implications for further research.