Facial Emotion Recognition and Emotional Memory From the Ovarian-Hormone Perspective: A Systematic Review

Abstract

Background: We review original papers on ovarian-hormone status in two areas of emotional processing: facial emotion recognition and emotional memory. Ovarian-hormone status is operationalized by the levels of the steroid sex hormones 17β-estradiol (E2) and progesterone (P4), fluctuating over the natural menstrual cycle and suppressed under oral contraceptive (OCs) use. We extend previous reviews addressing single areas of emotional processing. Moreover, we systematically examine the role of stimulus features such as emotion type or stimulus valence and aim at elucidating factors that reconcile the inconsistent results.

Methods: We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and included papers published until September 2020 indexed in PubMed and Web of Science databases. Search terms were MeSH terms (emotional OR emotion) AND (X) AND (estrogen OR progesterone OR menstrual cycle OR oral contraceptives) with (X) representing our separately searched areas, resulting in (processing OR recognition OR empathy), and (memory OR recall). To be included, articles had to (1) be written and published in English, (2) examine healthy, non-pregnant adult women in their reproductive age, and (3) measure or at least estimate levels of E2 and P4. In PubMed, the search was (4) limited to humans and (5) to the search term present in the title or abstract.

Results: Features of the provided stimulus material (emotion type and/or valence) constitute a relevant influence that interacts with E2- and P4-related ovarian-hormone status. For instance, recognition of basic emotions appears to be more related to P4- than E2-levels. Quite consistent, OC intake (vs. natural menstrual cycling) was accompanied by impaired recognition accuracy of basic and also complex emotions, although not in a recent large-sample study assessing complex emotions. Memory recall of negative content was mainly enhanced by P4, especially after having been stressed.

Discussion and conclusion: We document the methodological diversity in the field, presumably contributing to the heterogeneity of results. More studies explicitly contrasting the early follicular phase, mid-cycle phase, mid-luteal, and OC intake while standardizing tasks are needed. Research would take advantage of using within-subject designs and accounting for the recognition of complex emotions.

Keywords: emotion recognition; emotional memory; estrogen; menstrual cycle; oral contraceptives; ovarian hormones; progesterone; sex hormones.

FIGURE 1

Flow chart showing detailed systematic search and selection process for emotion recognition.

FIGURE 2

Flow chart showing detailed systematic search and selection process for emotional memory.

FIGURE 3

Classification of the definition of cycle phases across the reviewed menstrual cycle studies. The bold-face titles of the rectangular boxes show the labels we use throughout the review, to refer to phases of the menstrual cycle. The three horizontal stripes in the middle show the idealized 28 cycle days and the associated levels of 17β-estradiol (E2, green) and progesterone (P4, orange). The color gradient signifies hormone levels, with the highest levels shown in the darkest color and the lowest in the lightest color. The boxes are arranged so that the width of a box reflects the menstrual cycle days included under the specific label and the associated hormone levels. Entries in each box (small font) reflect the individual studies we combined under the same label, with their specific cycle days and their own cycle-phase labels. E.g., 2 × LU: 15-28 in the “Luteal”-box implies that two studies labeled cycle days from 15 to 28 days as the luteal phase. The figure serves to illustrate the variety of labels and included cycle days for the follicular and the luteal phase. Abbreviations. E2: 17β-estradiol; FO: follicular; LU: luteal; P4: progesterone. [number] × …: number of studies using the referred labeling; blue print: emotion recognition studies; black print: emotional memory studies; (+): more than a 28-day cycle.