Hormonal contraceptives, menstrual cycle and brain response to faces

Abstract

Both behavioral and neuroimaging evidence support a female advantage in the perception of human faces. Here we explored the possibility that this relationship may be partially mediated by female sex hormones by investigating the relationship between the brain's response to faces and the use of oral contraceptives, as well as the phase of the menstrual cycle. First, functional magnetic resonance images were acquired in 20 young women [10 freely cycling and 10 taking oral contraception (OC)] during two phases of their cycle: mid-cycle and menstruation. We found stronger neural responses to faces in the right fusiform face area (FFA) in women taking oral contraceptives (vs freely cycling women) and during mid-cycle (vs menstruation) in both groups. Mean blood oxygenation level-dependent response in both left and right FFA increased as function of the duration of OC use. Next, this relationship between the use of OC and FFA response was replicated in an independent sample of 110 adolescent girls. Finally in a parallel behavioral study carried out in another sample of women, we found no evidence of differences in the pattern of eye movements while viewing faces between freely cycling women vs those taking oral contraceptives. The imaging findings might indicate enhanced processing of social cues in women taking OC and women during mid-cycle.

Keywords: eye movements; fMRI, fusiform face area (FFA); menstrual cycle; oral contraception (OC).

Fig. 1

(A) Effect of OC (pill vs freely cycling). The left image shows the effect of pill during ambiguous face condition, the right image shows the effect of pill during angry face condition. (B) Effect of phase (mid-cycle vs menstruation). The left image shows the effect of phase during ambiguous face condition, the right image shows the effect of phase during angry face condition. (C) Effect of pill duration on mean BOLD response. The left image shows the effect of pill duration on left FFA during ambiguous condition, the right image shows the effect of pill duration on left FFA during angry condition. Each women is represented by a number. Data obtained in menstruation and mid-cycle phase are represented by squares and circles, respectively.

Fig. 2

(A) Experiment I — effect of pill and cycle phase on BOLD response in FFA in young women. (B) Experiment II — effect of pill on BOLD response in FFA in adolescent females.

Fig. 3

(A) Experiment I — unionized FFA masks created for angry (red) and ambiguous (yellow) condition. (Their intersection is in orange). (B) Experiment II — unionized FFA masks created for angry (red) and ambiguous (yellow) condition. (Their intersection is in orange).