Effects of menstrual cycle on electrophysiological correlates of selective auditory spatial attention

The fluctuations in steroid hormones associated with the female menstrual cycle have been suggested to modulate auditory processing. This study focused on cycle-dependent changes in the electrophysiological correlates of sound localization in a cocktail-party situation. Event-related-potentials were recorded at three (1 - luteal, 2 - menses, 3 - follicular) phases in women not taking hormonal contraceptives, at three corresponding points in time in women taking oral hormonal contraceptives, and in men. An effect of phase in women was obtained exclusively for the N2 component, which may reflect processes of auditory selective spatial attention. N2 amplitudes were strongest in phase 1 (luteal phase or initial phase of pill intake) and lowest in phase 2 (menses or pause of pill intake). Compared with the male group, the N2 amplitudes were lower in women in phase 2, but not in phase 1 and 3. Cortical source localization at the time of the N2 revealed a related modulation of electrical activity in right superior frontal sulcus depending on phase. Also, electrical activity in left inferior frontal gyrus was increased in women in phase 2 compared with men. These results suggest that neural processing in the cocktail-party task is modulated by female steroid hormones, irrespective of whether the change in hormone concentrations was caused by the natural cycle or by intake of synthetic steroids. Since the N2 component was increased when concentrations of estrogen and progesterone are known to be maximal, it seems as if these hormones enhance brain processes of auditory selective spatial attention. HighlightsO_LIN2 amplitude varied depending on cycle phase and contraceptive pill intake C_LIO_LIN2 amplitudes were lowest during low-hormone phases C_LIO_LIRelated changes in electrical activity were localized in frontal cortex C_LIO_LIAuditory spatial attention may be modulated by female sex hormones C_LI