Effects of sex hormonal levels and phases of the menstrual cycle in the processing of emotional faces

Role of estrogen in sex differences in memory, emotion and neuropsychiatric disorders

Estrogen regulates a wide range of neuronal functions in the brain, such as dendritic spine formation, remodeling of synaptic plasticity, cognition, neurotransmission, and neurodevelopment. Estrogen interacts with intracellular estrogen receptors (ERs) and membrane-bound ERs to produce its effect via genomic and non-genomic pathways. Any alterations in these pathways affect the number, size, and shape of dendritic spines in neurons associated with psychiatric diseases. Increasing evidence suggests that estrogen fluctuation causes changes in dendritic spine density, morphology, and synapse numbers of excitatory and inhibitory neurons differently in males and females. In this review, we discuss the role of estrogen hormone in rodents and humans based on sex differences. First, we explain estrogen role in learning and memory and show that a high estrogen level alleviates the deficits in learning and memory. Secondly, we point out that estrogen produces a striking difference in emotional memories in men and women, which leads them to display sex-specific differences in underlying neuronal signaling. Lastly, we discuss that fluctuations in estrogen levels in men and women are related to neuropsychiatric disorders, including schizophrenia, autism spectrum disorder (ASD), attention deficit hyperactivity disorder (ADHD), bipolar disorder (BPD), major depressive disorder (MDD), substance use disorder (SUD), and anxiety disorders.

Does the interplay of emotion-related personality traits and reproductive hormones predict individual variation in emotion recognition?

Person-related variation has been identified in many socio-cognitive domains, and there is evidence for links between certain personality traits and individual emotion recognition. Some studies, utilizing the menstrual cycle as a hormonal model, attempted to demonstrate that hormonal fluctuations could predict variations in emotion recognition, but with merely inconsistent findings. Remarkably, the interplay between hormone fluctuations and other person-related factors that could potentially influence emotion recognition remains understudied. In the current study, we examined if the interactions of emotion-related personality traits, namely openness, extraversion, and neuroticism, and the ovulatory cycle predict individual variation in facial emotion recognition in healthy naturally cycling women. We collected salivary ovarian hormones measures from N = 129 (n = 72 validated via LH test) women across their late follicular and mid-luteal phases of the ovulatory cycle. The results revealed a negative association between neuroticism scores and emotion recognition when progesterone levels (within-subject) were elevated. However, the results did not indicate a significant moderating influence of neuroticism, openness, and extraversion on emotion recognition across phases (late follicular vs. mid-luteal) of the menstrual cycle. Additionally, there was no significant interaction between openness or extraversion and ovarian hormone levels in predicting facial emotion recognition. The current study suggests future lines of research to compare these findings in a clinical setting, as both neuroticism and ovarian hormone dysregulation are associated with some psychiatric disorders such as premenstrual dysphoric disorder (PMDD).

Emotion recognition and mood along the menstrual cycle

Previous studies have demonstrated menstrual cycle dependent changes in the recognition of facial emotional expressions, specifically the expression of fear, anger, sadness or disgust. While some studies demonstrate an improvement of emotion recognition performance during the peri-ovulatory phase, when estradiol levels peak, other studies demonstrate a deterioration of emotion recognition performance during the mid-luteal phase, when progesterone levels peak. It has been hypothesized, that these changes in emotion recognition performance mirror mood changes along the menstrual cycle. In the present study, we investigate, whether changes in emotion recognition performance along the menstrual cycle are mediated by mood changes along the menstrual cycle. In a combined cross-sectional and longitudinal study design, two large samples of women completed an emotion recognition task, as well as several mood questionnaires during their menses, peri-ovulatory or mid-luteal cycle phase. 65 women completed the task thrice, once during each cycle phase, order counterbalanced. In order to control for potential learning effects, a sample of 153 women completed the task only once in one of the three cycle phases. In both samples, results demonstrated no significant changes in emotion recognition performance along the menstrual cycle, irrespective of the performance measure investigated (accuracy, reaction time, frequency of emotion classifications) and irrespective of the emotion displayed. Bayesian statistics provided very strong evidence for the null hypothesis, that emotion recognition does not change along the menstrual cycle. There was also no moderation of emotion recognition changes along the menstrual cycle by mood changes along the menstrual cycle. Mood changes along the menstrual cycle followed the expected pattern with highest positive affect and least premenstrual symptoms around ovulation and lowest positive affect, but strongest premenstrual symptoms during menses. Interestingly, premenstrual symptoms were negatively related to estradiol, suggesting a protective effect of estrogen during the luteal cycle phase against mood worsening during the premenstrual phase.

Does emotion recognition change across phases of the ovulatory cycle?

Recognizing emotions is an essential ability for successful interpersonal interaction. Prior research indicates some links between the endocrine system and emotion recognition ability, but only a few studies focused on within-subject differences across distinct ovulatory cycle phases and this ability. These studies have demonstrated mixed results that might be potentially due to heterogeneity in experimental tasks, methodologies, and lacking ecological validity. In the current study, we investigated associations between within-subject differences in ovarian hormones levels and emotion recognition from auditory, visual, and audiovisual modalities in N = 131 naturally cycling participants across the late follicular and mid-luteal phase of the ovulatory cycle. We applied a within-subject design with sessions in the late follicular and mid-luteal cycle phase, and also assessed salivary progesterone and estradiol in these sessions. Our findings did not reveal any significant difference in emotion recognition ability across two cycle phases. Thus, they emphasize the necessity of employing large-scale replication studies with well-established study designs along with proper statistical analyses. Moreover, our findings indicate that the potential link between ovulatory cycle phases (late follicular and mid-luteal) and emotion recognition ability might have been overestimated in previous studies, and may contribute to theoretical and practical implications of socio-cognitive neuroendocrinology.

Menstrual cycle and exogenous attention toward emotional expressions

Several studies suggest that the menstrual cycle affects emotional processing. However, these results may be biased by including women with premenstrual syndrome (PMS) in the samples. PMS is characterized by negative emotional symptomatology, such as depression and/or anxiety, during the luteal phase. This study aimed to explore the modulation of exogenous attention to emotional facial expressions as a function of the menstrual cycle in women without PMS. For this purpose, 55 women were selected (from an original volunteer sample of 790) according to rigorous exclusion criteria. Happy, angry, and neutral faces were presented as distractors, while both behavioral performance in a perceptual task and event-related potentials (ERPs) were recorded. This task was applied during both phases of the menstrual cycle (luteal and follicular, counterbalanced), and premenstrual symptomatology was monitored daily. Traditional and Bayesian ANOVAs on behavioral data (reaction times and errors in the task) and ERP indices (P1, N170, N2, and LPP amplitudes) confirmed the expected lack of an interaction of phase and emotion. Taken together, these results indicate that women free of PMS present steady exogenous attention levels to emotionally positive and negative stimuli regardless of the menstrual phase.

The Effect of Menstrual Cycle Phases on Approach-Avoidance Behaviors in Women: Evidence from Conscious and Unconscious Processes

The menstrual cycle affects women’s emotional states, with estrogen and progesterone having predominant roles. However, it remains unclear whether the phases of the menstrual cycle also affect women’s motivational behaviors. In this study, the main aim was to investigate how the menstrual cycle influences approach–avoidance behavior under conditions of conscious versus unconscious processing of emotions. Briefly, after recruitment by advertisement and screening with a menstrual cycle survey questionnaire, 27 naturally cycling, healthy women participated in an improved “manikin task” and were presented both positive and negative emotional stimuli during early follicular, late follicular, and mid-luteal phases. Estrogen and progesterone levels were measured. Women in the late follicular phase exhibited the shortest response times for approaching positive stimuli, while women in the mid-luteal phase exhibited the shortest response times for avoiding negative stimuli. Estrogen and progesterone levels significantly correlated with the speed of the approach–avoidance responses observed for the women, indicating the important role that sex hormones have in mediating emotionally motivated behavior. Overall, these findings suggest that the menstrual cycle has strong and specific influences on women’s approach–avoidance behaviors that are in part mediated by estrogen and progesterone. By identifying characteristics of these behaviors in the late follicular and mid-luteal phases, greater insight can be provided to women regarding the physiological influences of the menstrual cycle on their personal growth and security.

The attention-emotion interaction in healthy female participants on oral contraceptives during 1-week escitalopram intake

Previous findings in healthy humans suggest that selective serotonin reuptake inhibitors (SSRIs) modulate emotional processing via earlier changes in attention. However, many previous studies have provided inconsistent findings. One possible reason for such inconsistencies is that these studies did not control for the influence of either sex or sex hormone fluctuations. To address this inconsistency, we administered 20 mg escitalopram or placebo for seven consecutive days in a randomized, double-blind, placebo-controlled design to sixty healthy female participants with a minimum of 3 months oral contraceptive (OC) intake. Participants performed a modified version of an emotional flanker task before drug administration, after a single dose, after 1 week of SSRI intake, and after a 1-month wash-out period. Supported by Bayesian analyses, our results do not suggest a modulatory effect of escitalopram on behavioral measures of early attentional-emotional interaction in female individuals with regular OC use. While the specific conditions of our task may be a contributing factor, it is also possible that a practice effect in a healthy sample may mask the effects of escitalopram on the attentional-emotional interplay. Consequently, 1 week of escitalopram administration may not modulate attention toward negative emotional distractors outside the focus of attention in healthy female participants taking OCs. While further research in naturally cycling females and patient samples is needed, our results represent a valuable contribution toward the preclinical investigation of antidepressant treatment.

Pregnancy and brain architecture: Associations with hormones, cognition and affect

Sex hormones such as estradiol (E2) have long-lasting influence on brain architecture. Recent studies indicate further structural changes during hormonal transition periods including pregnancy, when women experience the greatest increase in sex hormone levels across their life span. In the present study, three groups of women (n = 44) with different levels of E2 underwent structural magnetic resonance imaging: (1) first-time pregnant women (n = 13, 'extreme E2 group'); (2), nulliparous, naturally cycling women who received 12 mg of E2 valerate (n = 16, 'high E2 group'); and (3) nulliparous, naturally cycling women receiving a placebo and hence low E2 (n = 15, 'low E2 group'). Blood samples were taken to assess hormonal levels. Moreover, parameters for cognition, emotion regulation and affect were assessed. On the neuronal level, the extreme E2 compared to the high E2 group showed a reduced gray matter volume in the left putamen. However, no significant differences were found between the low vs. high E2 groups, nor between the low E2 and extreme E2 groups. Cognitive performance was reduced in the extreme E2 group, although a positive affect was increased compared to the high E2 and low E2 groups. Furthermore, regression analyses revealed several associations between cognition, subjective measures of affect, emotion regulation and gray matter volume. A volume reduction of the left putamen during pregnancy further supports the notion that the female brain is shaped by hormonal transition phases, possibly preparing women for their future roles (e.g., pregnant women for their role as mothers).

No Evidence for a Role of Oral Contraceptive-Use in Emotion Recognition But Higher Negativity Bias in Early Follicular Women

Accuracy in facial emotion recognition has shown to vary with ovarian hormones, both in naturally cycling women, as well as in women taking oral contraceptives. It remains uncertain however, if specific – endogenous and exogenous – hormonal levels selectively impact recognition of certain basic emotions (or neutral faces) and if this relationship coincides with certain affective states. Therefore, we investigated 86 women under different hormonal conditions and compared their performance in an emotion recognition task as well as self-reported measures of affective states. Based on self-reported cycle days and ovulation testing, the participants have been split into groups of naturally cycling women during their early follicular phase (fNC, n = 30), naturally cycling women during their peri-ovulatory phase (oNC, n = 26), and women taking oral contraceptives (OC, n = 30). Participants were matched for age and did not differ in education or neuropsychological abilities. Self-reported anxiety and depressive affective state scores were similar across groups, but current affective state turned out to be significantly more negative in fNC women. Independent of negative affective state, fNC women showed a significantly higher negativity bias in recognizing neutral faces, resulting in a lower recognition accuracy of neutral faces compared to oNC and OC women. In the OC group only, negative affective state was associated with lower recognition accuracy and longer response times for neutral faces. Furthermore, there was a significant, positive association between disgust recognition accuracy and negative affective state in the fNC group. Low progesterone levels during the early follicular phase were linked to higher negative affective state, whereas in the peri-ovulatory phase they were linked to elevated positive affective state. Overall, previous findings regarding impaired emotion recognition during OC-use were not confirmed. Synthetic hormones did not show a correlation with emotion recognition performance and affective state. Considering the important role of emotion recognition in social communication, the elevated negativity bias in neutral face recognition found for fNC women may adversely impact social interactions in this hormonal phase.

Hormonal abnormalities in alexithymia

Alexithymia is a personality trait characterized by difficulties in emotion recognition and regulation that is associated with deficits in social cognition. High alexithymia levels are considered a transdiagnostic risk factor for a range of psychiatric and medical conditions, including depression, anxiety, and autism. Hormones are known to affect social-emotional cognition and behavior in humans, including the neuropeptides oxytocin and vasopressin, the steroid hormones testosterone and estradiol, the stress hormone cortisol as well as thyroid hormones. However, few studies have investigated hormonal effects on alexithymia and on alexithymia-related impairments in emotion regulation and reactivity, stress response, and social cognition. Here, we provide a brief overview of the evidence linking alexithymia to abnormalities in hormone levels, particularly with regard to cortisol and oxytocin, for which most evidence exists, and to thyroid hormones. We address the current lack of research on the influence of sex hormones on alexithymia and alexithymia-related deficits, and lastly provide future directions for research on associations between hormonal abnormalities and deficits in emotion regulation and social cognition associated with alexithymia.

Facial threat affects trust more strongly than facial attractiveness in women than it does in men

Trust is essential in initiating social relationships. Due to the differential evolution of sex hormones as well as the fitness burdens of producing offspring, evaluations of a potential mating partner's trustworthiness likely differ across sexes. Here, we explore unknown sex-specific effects of facial attractiveness and threat on trusting other-sex individuals. Ninety-three participants (singles; 46 women) attracted by the other sex performed an incentivized trust game. They had to decide whether to trust individuals of the other sex represented by a priori-created face stimuli gradually varying in the intensities of both attractiveness and threat. Male and female participants trusted attractive and unthreatening-looking individuals more often. However, whereas male participants' trust behavior was affected equally by attractiveness and threat, female participants' trust behavior was more strongly affected by threat than by attractiveness. This indicates that a partner's high facial attractiveness might compensate for high facial threat in male but not female participants. Our findings suggest that men and women prioritize attractiveness and threat differentially, with women paying relatively more attention to threat cues inversely signaling parental investment than to attractiveness cues signaling reproductive fitness. This difference might be attributable to an evolutionary, biologically sex-specific decision regarding parental investment and reproduction behavior.

Sex-hormone status and emotional processing in healthy women

Fluctuations of sex hormones across the menstrual cycle allow investigating the role of 17-β estradiol and progesterone in emotional processing. We examined emotional memory, empathy-related measures, as well as mimic and skin-conductance responses to affective stimuli in 72 women either in the mid-cycle (MC-group: moderate to high estradiol, low progesterone), the later cycle (LC-group: high progesterone, moderate estradiol), or during oral contraceptive use (OC-group: low endogenous ovarian-hormone levels). In the first session, affective pictures were presented (memory encoding) while recording mimic and skin-conductance responses. Additionally, participants were exposed to a post-encoding stressor (cold pressor test). After 24 h, we tested surprise recall as well as empathy-related performance. Emotional memory was not affected by the hormone-status group, stressor, or salivary hormone levels. For the cognitive empathy-related measure, hormone status interacted with the protagonist gender. Women in the LC- and OC-groups identified emotions more accurately if depicted by female protagonists, yet the MC-group identified emotions depicted by men and women equally well. Correspondingly, the number of correctly identified emotions from male protagonists correlated positively with estradiol levels. In the affective empathy-related ratings, the OC-group showed a negativity bias, rating negative (vs. positive) emotions higher, although not associated with hormone levels. Mimic responses were not modulated by hormone-status group or related to hormone levels. Skin-conductance responses to negative pictures were heightened in the LC-group and correlated positively with progesterone levels. These data suggest a differential impact of female sex hormones on emotional processing, i.e., empathy-related performance and affective sympathetic reactivity, but not in emotional memory or affective mimic reactivity.

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

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.

Oxytocin effects on the resting-state mentalizing brain network

Oxytocin (OT) has modulatory effects in both human behavior and in the brain, which is not limited in the specific brain area but also with the potential effect on connectivity with other brain regions. Evidence indicates that OT effects on human behavior are multifaceted, such as trust behavior, decrease anxiety, empathy and bonding behavior. For the vital role of mentalizing in understanding others, here we examine whether OT has a general effect on mentalizing brain network which is associated to the effect of related social behavioral and personality traits. Using a randomized, double-blind placebo-controlled group design, we investigate the resting-state functional magnetic resonance imaging after intranasal OT or placebo. The functional connectivity (FC) maps with seed in left/right temporoparietal junction (lTPJ/rTPJ) showed that OT significantly increased connectivity between rTPJ and default attention network (DAN), but decreased the FC between lTPJ and medial prefrontal network (MPN). With machine learning approach, we report that identified altered FCs of TPJ can classify OT and placebo (PL) group. Moreover, individual's empathy trait can modulate the FC between left TPJ and right rectus (RECT), which shows a positive correlation with empathic concern in PL group but a negative correlation in OT group. These results demonstrate that OT has significant effect on FC with lTPJ and rTPJ, brain regions where are critical for mentalizing, and the empathy concern can modulate the FC. These findings advance our understanding of the neural mechanisms by which OT modulates social behaviors, especially in social interaction involving mentalizing.

Friend vs. Foe: Cognitive and Affective Empathy in Women With Different Hormonal States

Empathy is crucial for social functioning as well as social coherence. It can be influenced by modulatory factors such as familiarity and liking (i.e., emotional closeness). Furthermore, there are first hints that hormonal status may modulate affective but not cognitive empathy in women. The aim of this study was to investigate potential separate as well as combined modulatory effects of emotional closeness and hormonal status on female cognitive and affective empathy. Three hormonal status groups of women (n = 62) were studied: (1) naturally-cycling (NC) women in the early follicular phase (fNC), (2) NC women during periovulatory phase (oNC), and (3) oral contraceptive (OC) users. All women underwent a newly developed empathy task (i.e., Tübinger Empathy Test, TET) presenting textual descriptions of positive and negative emotional scenes relating to three different perspectives (i.e., self vs. friend vs. enemy/disliked person). Regardless of hormonal status, empathic responses were higher for the friend compared to the enemy perspective for both empathy components. However, cognitive empathy was less affected by varying emotional closeness toward the target person than affective empathy. Hormonal status modulated only affective empathy. OC users showed significantly less affective empathy toward the enemy compared to the fNC women. Overall, affective empathy seems more sensitive to modulatory effects of emotional closeness and hormonal status than cognitive empathy. Possible implications of this current investigation for future research on empathy and OC use, contraceptive education as well as for other clinical applications are discussed.

The role of olfaction and sex-hormone status in empathy-related measures

Reports of a female advantage in empathy-related measures suggest a role for sex hormones, although the data are inconsistent. Studies also report similar sex differences in human olfactory perception. In rodents, olfaction is involved in detecting and integrating socially relevant information and is modulated by the brain actions of estrogens. We hypothesized that olfaction may untangle the mixed evidence on the relationship between sex hormones and empathy-related measures (cognitive and affective) in humans. To test this, we examined 60 healthy participants in three sex-hormone-status groups: free-cycling women tested in cycle phases with higher 17-β estradiol and progesterone, oral-contraceptive users (low estradiol and progesterone), and men. We assessed empathy-related measures, facial mimicry (from zygomaticus and corrugator muscle activity), and odor discrimination ability. In the empathy-related measures and facial mimicry, we did not find overall group effects or meaningful associations with salivary levels of estradiol, progesterone, or testosterone. Free-cycling women only outperformed men in the recognition of emotions from pictures of the eye region, but sex hormones were unrelated to emotion recognition performance. Oral contraceptive users showed higher scores in the affective empathy-related measure when viewing negative emotions, with no relation to hormone levels. Free-cycling women exhibited the strongest facial mimicry (viewing female, but not male protagonists), positively associated with progesterone. Finally, the groups differed in odor discrimination, with free-cycling women outperforming men. However, odor discrimination ability and empathy-related performance were not correlated. Our results support a role of sex hormones in odor perception and in empathy-related measures, to a certain extent. However, no common underlying mechanism was found.

Hormonal Contraception and Depression: Updated Evidence and Implications in Clinical Practice

Hormonal contraceptives are used worldwide by more than 100 million women. Some studies have been published about the possible appearance of depressive symptoms when using hormonal contraceptives, but this link is still a matter of debate. The purpose of this review is to provide an update of the literature on this issue, and to investigate the possible explanations of this problem based on animal and human studies. The main pathway responsible for menstrual cycle-related mood changes is the γ-aminobutyric acid pathway, which is sensitive to changes in the levels of progesterone and of its metabolites, the neurosteroids. In particular, allopregnanolone is a potentiating neurosteroid with anxiolytic and anti-convulsant effects whose levels change during a normal menstrual cycle together with progesterone levels. Progestins have different effects on allopregnanolone, mainly owing to their diverse androgenicity. Moreover, they might affect brain structure and function, even though the meaning of these changes has yet to be clarified. It is important to define the groups of women in which negative mood disorders are more likely to occur. Adolescence is a critical period and this age-specific vulnerability is complex and likely bidirectional. Moreover, women with a history of mood affective disorders or premenstrual dysphoric syndrome are at a higher risk when taking contraceptives. In this review, we aim to provide clinicians with advice on how to approach these difficult situations.

Mapping changes in women's visual functions during the menstrual cycle: narrative review

BACKGROUND

This article systematically updates the literature on changes in visual functions during the phases of the normal menstrual cycle in women.

OBJECTIVES

To update Guttridge's 1994 review of visual structures and functions associated with the menstrual cycle and broaden the search through psychophysical, neuroimaging and neurobehavioral measurements covering 1994-2020.

DESIGN AND SETTING

Narrative review conducted in a neurosciences and behavior laboratory in Brazil.

METHODS

The PubMed, Cochrane Clinical Answers and Google Scholar databases were searched. After screening and applying the eligibility criteria, 32 articles were examined. Through this analysis, the following information was extracted: (1) geographical distribution of the study; (2) sample size (according to age and phase of the menstrual cycle); (3) type of measurements according to psychophysical, neuroimaging and neurobehavioral instruments; (4) vision testing model; (5) visual subcategory evaluated; (6) categories of processed visual stimuli; and (7) main findings.

RESULTS

The menstrual phases give rise to significant changes in visual functions, including in relation to orientation and spatial attention, visual campimetry and visual sensitivity. These relate specifically to the follicular and luteal phases.

CONCLUSIONS

These findings theoretically expand the effects of menstrual cycles on visual functions found by Guttridge (1994). Despite some inconsistencies in the studies analyzed, it was found that visual processing during the follicular and luteal phases of the normal menstrual cycle of healthy women can explain physiological, cognitive, behavioral and social modulations.

Shaping of the Female Human Brain by Sex Hormones: A Review

Traditionally sex hormones have been associated with reproductive and developmental processes only. Since the 1950s we know that hormones can have organizational effects on the developing brain and initiate hormonal transition periods such as puberty. However, recent evidence shows that sex hormones additionally structure the brain during important hormonal transition periods across a woman's life including short-term fluctuations during the menstrual cycle. However, a comprehensive review focusing on structural changes during all hormonal transition phases of women is still missing. Therefore, in this review structural changes across hormonal transition periods (i.e., puberty, menstrual cycle, oral contraceptive intake, pregnancy and menopause) were investigated in a structured way and correlations with sex hormones evaluated. Results show an overall reduction in grey matter and region-specific decreases in prefrontal, parietal and middle temporal areas during puberty. Across the menstrual cycle grey matter plasticity in the hippocampus, the amygdala as well as temporal and parietal regions were most consistently reported. Studies reporting on pre- and post-pregnancy measurements revealed volume reductions in midline structures as well as prefrontal and temporal cortices. During perimenopause, the decline in sex hormones was paralleled with a reduction in hippocampal and parietal cortex volume. Brain volume changes were significantly correlated with estradiol, testosterone and progesterone levels in some studies, but directionality remains inconclusive between studies. These results indicate that sex hormones play an important role in shaping women's brain structure during different transition periods and are not restricted to specific developmental periods.

High progesterone levels facilitate women's social information processing by optimizing attention allocation

Ovarian hormones exert an influence on social information processing, in which, however, the exact roles of estradiol and progesterone remain unclear. This study examines the specific influences of these two ovarian hormones on social information processing across the menstrual cycle using the emotional face flanker task and attentional network test (ANT). Twenty-six naturally cycling, healthy women were tested thrice: during menses, in the follicular phase, and in the luteal phase. In the emotional face flanker task, a significant positive relation was found between progesterone levels and reaction times (RTs) for sad faces, suggesting that high progesterone levels may activate the social monitoring system and allocate more attention to the social stimulus, which benefits individuals' survival and adaptation. In the ANT, a significant increase was found in RTs and accuracy during the luteal phase, suggesting that luteal women increase this accuracy by exerting a relatively conservative strategy of allocating more attention to the targets. Taken together, these findings indicate that high levels of progesterone may facilitate social information processing by optimizing attention allocation. Moreover, overactivation of the social monitoring system may make women more susceptible to stressors and promote affective disturbances, which may provide underlying pathophysiology of the premenstrual dysphoric disorder.

Gender identity better than sex explains individual differences in episodic and semantic components of autobiographical memory: An fMRI study

Advances in the literature of sex-related differences in autobiographical memory increasingly tend to highlight the importance of psychosocial factors such as gender identity, which may explain these differences better than sex as a biological factor. To date, however, none of these behavioral studies have investigated this hypothesis using neuroimaging. The purpose of this fMRI study is to examine for the first time sex and gender identity-related differences in episodic and semantic autobiographical memory in healthy participants (M=19, W=18). No sex-related differences were found; however, sex-related effects of masculine and feminine gender identity were identified in men and women independently. These results confirm the hypothesis that differences in episodic and semantic autobiographical memory are best explained by gender but are an interaction between biological sex and gender identity and extend these findings to the field of neuroimaging. We discuss the importance of hormonal factors to be taken into consideration in the future.

Gender Role, But Not Sex, Shapes Humans' Susceptibility to Emotion

It is unknown whether the famous sex-related difference in emotion processing is accounted for by biological sex, gender role, or their interaction. To clarify the issue, in Study 1 we recorded event-related potentials in response to negative and positive images of diverse intensities when 47 masculine (26 males) and 47 feminine (22 males) subjects performed a non-emotional task. The occipital P1 and N1 amplitudes were larger in women than in men, while feminine subjects showed larger N1 amplitudes than masculine subjects, regardless of sex. Moreover, feminine subjects showed enhanced frontocentral N2 (210-270 ms) amplitudes for highly and mildly negative than for neutral stimuli, while masculine subjects showed an emotion effect only for highly negative stimuli. The feminine-specific effect for mildly negative stimuli was positively correlated to the feminine score, and this correlation was located to the anterior cingulate and the superior and medial frontal gyri. Furthermore, feminine but not masculine subjects showed enhanced parietal P3 (330-560 ms) amplitudes for highly and mildly positive than for neutral stimuli, an effect positively related to the feminine score and localized to the precuneus, posterior cingulate, and superior temporal gyrus. Machine learning analyses verified that single-trial N2 and P3 amplitudes of feminine subjects reliably discriminated the intensity of negative and positive stimuli, respectively. For ecological considerations, in Study 2 we used an observational approach (n = 300) and confirmed that feminine gender role, rather than biological sex, predicted individual differences in daily experience of emotion-related psychopathological symptoms. These findings provide solid evidence for the critical impact of gender role rather than sex on emotional susceptibility.

Reconsidering the role of sex hormones in psychopathy development: Estrogen and psychopathy among male justice-involved youth

Prominent theory suggests that factor one psychopathic traits may develop from increased input from hormones in the hypothalamic pituitary gonadal axis (HPG; i.e., testosterone) and decreased input from the hypothalamic pituitary adrenal axis (HPA; i.e., cortisol). Although there are extensive findings connecting low cortisol to psychopathy, less support has emerged for high levels of testosterone. This study examined whether incorporating the HPG hormone, estradiol, into this model would reveal relationships in line with theory: high levels of estradiol and testosterone in combination with low levels of cortisol would inform psychopathic traits. Baseline and reactive hormone levels were measured and compared to Psychopathy Checklist-Youth Version (PCL-YV) interviews among 66 male justice-involved youth (M age = 15.73) in a Southeastern juvenile detention center. The primary findings of this study were relationships between interacting HPA and HPG axis hormones with facet one and facet two psychopathic traits. Specifically, psychopathy total scores, interpersonal traits, and affective traits related to estradiol and testosterone reactivity, in that psychopathy scores were more likely with decreases in hormone reactivity (i.e., change in hormone level) following a stressor. Moreover, affective traits related to reactivity in all three hormones. These findings support inclusion of estradiol in neurobiological models of psychopathy and consideration of the individual components of psychopathy. This study adds to the growing body of research supporting interactions between variations in functioning of the HPA and HPG axes in relation to psychopathy.

Progesterone - Friend or foe?

Estradiol is the "prototypic" sex hormone of women. Yet, women have another sex hormone, which is often disregarded: Progesterone. The goal of this article is to provide a comprehensive review on progesterone, and its metabolite allopregnanolone, emphasizing three key areas: biological properties, main functions, and effects on mood in women. Recent years of intensive research on progesterone and allopregnanolone have paved the way for new treatment of postpartum depression. However, treatment for premenstrual syndrome and premenstrual dysphoric disorder as well as contraception that women can use without risking mental health problems are still needed. As far as progesterone is concerned, we might be dealing with a two-edged sword: while its metabolite allopregnanolone has been proven useful for treatment of PPD, it may trigger negative symptoms in women with PMS and PMDD. Overall, our current knowledge on the beneficial and harmful effects of progesterone is limited and further research is imperative.

Multimodal Affective State Assessment Using fNIRS + EEG and Spontaneous Facial Expression

Human facial expressions are regarded as a vital indicator of one's emotion and intention, and even reveal the state of health and wellbeing. Emotional states have been associated with information processing within and between subcortical and cortical areas of the brain, including the amygdala and prefrontal cortex. In this study, we evaluated the relationship between spontaneous human facial affective expressions and multi-modal brain activity measured via non-invasive and wearable sensors: functional near-infrared spectroscopy (fNIRS) and electroencephalography (EEG) signals. The affective states of twelve male participants detected via fNIRS, EEG, and spontaneous facial expressions were investigated in response to both image-content stimuli and video-content stimuli. We propose a method to jointly evaluate fNIRS and EEG signals for affective state detection (emotional valence as positive or negative). Experimental results reveal a strong correlation between spontaneous facial affective expressions and the perceived emotional valence. Moreover, the affective states were estimated by the fNIRS, EEG, and fNIRS + EEG brain activity measurements. We show that the proposed EEG + fNIRS hybrid method outperforms fNIRS-only and EEG-only approaches. Our findings indicate that the dynamic (video-content based) stimuli triggers a larger affective response than the static (image-content based) stimuli. These findings also suggest joint utilization of facial expression and wearable neuroimaging, fNIRS, and EEG, for improved emotional analysis and affective brain-computer interface applications.

Electrophysiological and Behavioral Indices of the Role of Estrogens on Memory Processes for Emotional Faces in Healthy Young Women

It is well known that estrogens influence cognitive activities, such as memory, and emotional states. The objective of the present study was to investigate the role of estrogens in the short-term memory processing of basic emotional face expressions, by means of event-related potentials (ERPs) and a recognition memory (RM) behavioral task. Healthy young women were divided into a periovulatory (PO) group, characterized by high levels of estrogens and low levels of progesterone, and an early follicular (EF) group, characterized by low levels of both estrogens and progesterone. During the RM task, all subjects viewed images of faces expressing six basic emotions (happiness, anger, disgust, sadness, surprise, fear) and one neutral expression while their electrophysiological activity was recorded. We considered P300 components, amplitude, and latency in response to each stimulus. Soon after the presentation of each stimulus face, a target image was presented, consisting of two faces, one of which was the same, while the other was a chimerical face, obtained by mixing the upper or lower halves of the faces of the stimulus image with a different emotion. The subjects had to choose between the two alternatives, and the reaction time (RT) and accuracy of response (RM errors) were measured. The main findings of this study showed that P300 amplitudes are significantly higher in response to the expressions of happiness, but significantly lower for sadness, in PO compared to EF. The P300 data are consistent with performance in the RM task and with the measures of RT. The interest in the emotion of happiness, unlike sadness, during the PO phase may reflect the evolutionary significance of female sex hormones linked to mating behavior.

Do women expose themselves to more health-related risks in certain phases of the menstrual cycle? A meta-analytic review

Researchers have increasingly examined the menstrual cycle as a potential source of day-to-day variation in women's cognitions, motivations, and behavior. Within this literature, several lines of research have examined the impact of the menstrual cycle on women's engagement in activities that could negatively affect their health (alcohol and tobacco consumption, sexual behavior, risk recognition). However, findings have been mixed, leaving it unclear whether women may expose themselves to more health-related risks during certain phases of the cycle. We conducted a meta-analysis of 22 published and four unpublished studies (N = 7529, https://osf.io/xr37j/). The meta-analysis revealed shifts across the menstrual cycle in women's sexual behavior with others and risk recognition (higher in ovulatory phase), whereas there was no consistent pattern of difference for alcohol and cigarette consumption. These findings help to clarify the proximate physiological and evolutionary mechanisms underlying women's health-related risk-taking and may inform new interventions.

Phase of the menstrual cycle affects engagement of attention with emotional images

Changes that occur during the menstrual cycle affect various aspects of behavior, cognition, and emotion. Here, we focused on potential differences between early follicular and midluteal phases in the way women process images of behaviorally relevant content categories: children, threat, disgust, erotic scenes, low- and high-calorie food. Using eye-tracking, we examined women's engagement of attention in the key region of each image in a free-viewing condition. Specifically, we tested how quickly attention was attracted to these regions and for how long it was held there. Participants took part in two experimental sessions, one in the early follicular and one in the midluteal phase. The results showed that in the midluteal phase attention was attracted to the key region earlier than in the early follicular phase: the first fixation more often fell within the key region and there were fewer fixations preceding it. While the effect of the phase in terms of the capture of attention did not depend on the image category, the effect regarding the hold of attention was category-specific, concerning the disgust category only. Specifically, in the midluteal phase the duration of the exploration of the key region between reaching it for the first time and first exiting it was shorter, which might be due to heightened sensitivity to disgusting stimuli in this period. Overall, our results indicate the occurrence of changes in attentional processing of emotional scenes related to the menstrual cycle, which seem to differ depending on the aspect of attention deployment: in the midluteal phase the effect of enhancing orienting was general and concerned any important visual information, whereas the effect of the shortened hold of attention appeared to be limited to specific content.

The expectant social mind: A systematic review of face processing during pregnancy and the effect of depression and anxiety

Pregnancy carries enormous changes in the psychological and neurophysiological domains. It has been suggested that pregnant women undergo a cognitive reorganization aimed at increasing the salience of social stimuli (i.e., the tendency of social cues to capture observer's attention, so that their processing results prioritized). The goal of the present work was to systematically review the empirical evidence of a change in face processing during pregnancy. Moreover, we explored whether face processing is associated with antenatal depression and anxiety and the extent to which this is part of a potential mechanism to explain detrimental effects of maternal psychopathology on infant outcomes. We identified 19 relevant studies and discussed them based on their methodological qualities. The results of the review suggest that even though it is not possible to draw firm conclusions, pregnancy is likely to be a plasticity window for face processing at the behavioral and neural levels. Evidence confirms the detrimental effect of depression and anxiety on face processing during pregnancy. Clinical implications for parenting interventions are discussed.

Sex differences during emotion processing are dependent on the menstrual cycle phase

Sex differences in the neural processing of emotion are of special interest considering that mood and anxiety disorders predominant in females. However, these sex-related differences were typically studied without considering the hormonal status of female subjects, although emotion processing in the brain was shown to differ between phases of the menstrual cycle. In this functional MRI study, we demonstrated the influence of the menstrual cycle phase on sex differences in brain activity and functional connectivity during negative and positive emotions, using two different paradigms: emotion perception and emotion experience. Twenty naturally cycling healthy women without premenstrual symptoms were scanned twice: during the mid-follicular and late-luteal menstrual phases, and compared to a matched group of twenty healthy men. During negative emotion perception, men showed increased neural activity in the right hippocampal formation relative to women in the mid-follicular phase, and increased activity in the right cerebellum relative to women in the late-luteal phase. During experience of amusement, reduced putamen-ventrolateral prefrontal cortex and putamen-dorsomedial prefrontal cortex functional connectivity were observed for women in the late-luteal phase relative to men and associated with levels of sex hormones. These neural and hormonal findings were complemented by behavioral reports of reduced amusement and increased sadness in late-luteal women. Our results demonstrate menstrual phase-dependent sex differences in emotion perception and experience and may suggest a biological tendency for a deficient experience of pleasure and reward during the late-luteal phase. These findings may further shed light on the underlying pathophysiology of premenstrual dysphoric disorder.

Facial Sadness Recognition is Modulated by Estrogen Receptor Gene Polymorphisms in Healthy Females

Polymorphisms of the estrogen receptor ESR1 and ESR2 genes have been linked with cognitive deficits and affective disorders. The effects of these genetic variants on emotional processing in females with low estrogen levels are not well known. The aim was to explore the impact of the ESR1 and ESR2 genes on the responses to the facial emotion recognition task in females. Postmenopausal healthy female volunteers were genotyped for the polymorphisms Xbal and PvuII of ESR1 and the polymorphism rs1256030 of ESR2. The effect of these polymorphisms on the response to the facial emotion recognition of the emotions happiness, sadness, disgust, anger, surprise, and fear was analyzed. Females carrying the P allele of the PvuII polymorphism or the X allele of the Xbal polymorphism of ESR1 easily recognized facial expressions of sadness that were more difficult for the women carrying the p allele or the x allele. They displayed higher accuracy, fast response time, more correct responses, and fewer omissions to complete the task, with a large effect size. Women carrying the ESR2 C allele of ESR2 showed a faster response time for recognizing facial expressions of anger. These findings link ESR1 and ESR2 polymorphisms in facial emotion recognition of negative emotions.

Development of the Youth Emotion Picture Set

Several facial expression image sets have been developed. Nevertheless, there is a lack of facial expression sets comprising adolescents’ images depicting all basic emotions. This study aimed to fill this gap through the development of an image database of youth facial expressions, containing pictures of six basic emotions plus neutral. Posed and spontaneous expressions were collected from 31 youths, 12 to 20 years old; 2,279 frames were obtained, and an initial screening was conducted through the exclusion of similar frames, low intensity images, and ambiguous or blended expressions; 256 frames met criteria and were rechecked by two expert judges. Images were retained if they depicted all the prototypical features of the designated expression. A final selection was conducted to assure an image set that covered all age ranges, both sexes and an even number of images by expression, resulting in 42 frames (21 male, six of each emotion). Expert judges, independent adults, independent teenagers, and a software validation were used to assure database validity. Agreement across raters was high, and no differences were observed for posed and spontaneous images. The data set developed in this study can be a valid tool in studies of facial expressions, in particular, with adolescents’ samples.

Gender Differences in Processing Fearful and Angry Body Expressions

Previous studies have demonstrated differential perception of body expressions between males and females. However, only two recent studies (Kret et al., 2011; Krüger et al., 2013) explored the interaction effect between observer gender and subject gender, and it remains unclear whether this interaction between the two gender factors is gender-congruent (i.e., better recognition of emotions expressed by subjects of the same gender) or gender-incongruent (i.e., better recognition of emotions expressed by subjects of the opposite gender). Here, we used event-related potentials (ERPs) to investigate the recognition of fearful and angry body expressions posed by males and females. Male and female observers also completed an affective rating task (including valence, intensity, and arousal ratings). Behavioral results showed that male observers reported higher arousal rating scores for angry body expressions posed by females than males. ERP data showed that when recognizing angry body expressions, female observers had larger P1 for male than female bodies, while male observers had larger P3 for female than male bodies. These results indicate gender-incongruent effects in early and later stages of body expression processing, which fits well with the evolutionary theory that females mainly play a role in care of offspring while males mainly play a role in family guarding and protection. Furthermore, it is found that in both angry and fearful conditions male observers exhibited a larger N170 for male than female bodies, and female observers showed a larger N170 for female than male bodies. This gender-incongruent effect in the structural encoding stage of processing may be due to the familiarity of the body configural features of the same gender. The current results provide insights into the significant role of gender in body expression processing, helping us understand the issue of gender vulnerability associated with psychiatric disorders characterized by deficits of body language reading.

Females Are More Sensitive to Opponent's Emotional Feedback: Evidence From Event-Related Potentials

It is widely believed that females outperformed males in emotional information processing. The present study tested whether the female superiority in emotional information processing exists in a naturalistic social-emotional context, if so, what the temporal dynamics underlies. The behavioral and electrophysiological responses were recorded while participants were performing an interpersonal gambling game with opponents' facial emotions given as feedback. The results yielded that emotional cues modulated the influence of monetary feedback on outcome valuation. Critically, this modulation was more conspicuous in females: opponents' angry expressions increased females' risky tendency and decreased the amplitude of reward positivity (RewP) and feedback P300. These findings indicate that females are more sensitive to emotional expressions in real interpersonal interactions, which is manifested in both early motivational salience detection and late conscious cognitive appraisal stages of feedback processing.

Estradiol treatment in a nonhuman primate model of menopause preserves affective reactivity

Human affective life changes with age, becoming more positive and less negative in later life. This change occurs even as aging leads to declines in health and cognitive outcomes. Despite these well-documented effects in humans, the extent to which affective processes change as a result of aging in nonhuman animals, particularly nonhuman primates, is unclear. As a first step toward developing an animal model for human affective aging, we tested aged, surgically menopausal aged and middle-aged gonadally intact female rhesus monkeys (Macaca mulatta) on a classic index of affective reactivity in monkeys, the Human Intruder Task. The Human Intruder Task evaluates behavioral responses to varying levels of threat. Aged, surgically menopausal monkeys received hormone replacement therapy consisting of a cyclic estradiol regimen or vehicle injections as a control. Average responsivity to threat did not vary by condition, but middle-aged monkeys and aged monkeys on estradiol were more reactive to the most potent level of threat than to a moderate level of threat, replicating previously published results in other age groups and male monkeys. In contrast, aged monkeys who were not on estradiol did not show such calibration to threat level. These findings suggest that estrogen may be important for maintaining more youthful affective responding. They also illustrate the utility of behavioral assays of affective reactivity in nonhuman primate models of cognitive and reproductive aging in humans. (PsycINFO Database Record

Sex Hormones and Processing of Facial Expressions of Emotion: A Systematic Literature Review

Background: We systematically reviewed the literature to determine the influence of sex hormones on facial emotion processing (FEP) in healthy women at different phases of life. Methods: Searches were performed in PubMed, Web of Science, PsycINFO, LILACS, and SciELO. Twenty-seven articles were included in the review and allocated into five different categories according to their objectives and sample characteristics (menstrual cycle, oral contraceptives, pregnancy/postpartum, testosterone, and progesterone). Results: Despite the limited number of studies in some categories and the existence of inconsistencies in the results of interest, the findings of the review suggest that FEP may be enhanced during the follicular phase. Studies with women taking oral contraceptives showed reduced recognition accuracy and decreased responsiveness of different brain structures during FEP tasks. Studies with pregnant women and women in the postpartum showed that hormonal changes are associated with alterations in FEP and in brain functioning that could indicate the existence of a hypervigilant state in new and future mothers. Exogenous administration of testosterone enhanced the recognition of threatening facial expressions and the activation of brain structures involved in the processing of emotional stimuli. Conclusions: We conclude that sex hormones affect FEP in women, which may have an impact in adaptive processes of the species and in the onset of mood symptoms associated with the premenstrual syndrome.

Sex hormones play a role in vulnerability to sleep loss on emotion processing tasks

The central aim of this study was to investigate hormones as a predictor of individual vulnerability or resiliency on emotion processing tasks following one night of sleep restriction. The restriction group was instructed to sleep 3 a.m.–7 a.m. (13 men, 13 women in follicular phase, 10 women in luteal phase of menstrual cycle), and a control group slept 11 p.m.–7 a.m. (12 men, 12 follicular women, 12 luteal women). Sleep from home was verified with actigraphy. Saliva samples were collected on the evening prior to restriction, and in the morning and afternoon following restriction, to measure testosterone, estradiol, and progesterone. In the laboratory, event-related potentials (ERPs) were recorded during presentation of images and faces to index neural processing of emotional stimuli. Compared to controls, sleep-restricted participants had a larger amplitude Late Positive Potential (LPP) ERP to positive vs neutral images, reflecting greater motivated attention towards positive stimuli. Sleep-restricted participants were also less accurate categorizing sad faces and exhibited a larger N170 to sad faces, reflecting greater neural reactivity. Sleep-restricted luteal women were less accurate categorizing all images compared to control luteal women, and progesterone was related to several outcomes. Morning testosterone in men was lower in the sleep-restricted group compared to controls; lower testosterone was associated with lower accuracy to positive images, a greater difference between positive vs neutral LPP amplitude, and lower accuracy to sad and fearful faces. In summary, women higher in progesterone and men lower in testosterone were more vulnerable to the effects of sleep restriction on emotion processing tasks. This study highlights a role for sex and sex hormones in understanding individual differences in vulnerability to sleep loss.

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Sex and sex hormones play a role in individual differences in vulnerability to sleep loss.

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Women higher in progesterone and men lower in testosterone were more vulnerable to the effects of sleep restriction on emotion processing tasks.

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One night of sleep restriction was associated with lower testosterone in men.

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Sleep-restricted participants showed greater motivated attention towards positive picture stimuli compared to rested controls.

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Sleep-restricted participants were less accurate categorizing sad faces and exhibited a larger N170 ERP to sad faces, reflecting greater neural reactivity.

The Effects of Menstrual Cycle Phase on Processing of Emotional Images

Abstract. The ovarian hormone levels can affect subjective ratings and modulate late positive potential (LPP) amplitudes evoked by images of varying appeal. The present study examines how different progesterone levels influence the valence, arousal ratings and mean LPP amplitudes evoked by pleasant, neutral, and unpleasant images. Twenty-three healthy females were grouped by menstrual cycle days (estradiol and progesterone levels): 10 were included in the follicular phase group and 13 were included in the luteal phase group. Each female rated the affective images in terms of valence and arousal while event-related potentials (ERPs) were measured. The valence ratings of pleasant images were higher in follicular phase group than in luteal, but the same effect was not seen in the arousal ratings. The arousal ratings to unpleasant images were higher than those to pleasant in luteal, but not in follicular phase group. However, the mean amplitude of the early LPP (450–700 ms) was significantly greater to pleasant than to neutral and unpleasant stimuli, but did not differ between follicular and luteal phase groups. The mean amplitude of the late LPP (700–950 ms) was significantly larger to pleasant and unpleasant compared to neutral images, but did not differ between menstrual cycle phase groups. Correlation analysis showed a significant negative relationship between progesterone levels and arousal ratings of pleasant and unpleasant images in luteal phase group. Arousal scores for unpleasant images negatively correlated with mean LPP amplitudes to unpleasant images at Pz site in the luteal phase group. The present study provides evidence that subjective ratings of affective images of different attractiveness could be influenced by female menstrual cycle phase, but mean amplitudes of LPP (450–950 ms) are not affected. However, results of correlational analysis suggest that valence, arousal ratings and mean LPP amplitudes are susceptible to the influence of hormone progesterone in luteal phase.

The roots of empathy: Through the lens of rodent models

Empathy is a phenomenon often considered dependent on higher-order emotional control and an ability to relate to the emotional state of others. It is, by many, attributed only to species having well-developed cortical circuits capable of performing such complex tasks. However, over the years, a wealth of data has been accumulated showing that rodents are capable not only of sharing emotional states of their conspecifics, but also of prosocial behavior driven by such shared experiences. The study of rodent empathic behaviors is only now becoming an independent research field. Relevant animal models allow precise manipulation of neural networks, thereby offering insight into the foundations of empathy in the mammalian brains. Here we review the data on empathic behaviors in rat and mouse models, their neurobiological and neurophysiological correlates, and the factors influencing these behaviors. We discuss how simple rodent models of empathy enhance our understanding of how brain controls empathic behaviors.

The human body odor compound androstadienone leads to anger-dependent effects in an emotional Stroop but not dot-probe task using human faces

The androgen derivative androstadienone is a substance found in human sweat and thus is a putative human chemosignal. Androstadienone has been studied with respect to effects on mood states, attractiveness ratings, physiological and neural activation. With the current experiment, we aimed to explore in which way androstadienone affects attention to social cues (human faces). Moreover, we wanted to test whether effects depend on specific emotions, the participants' sex and individual sensitivity to smell androstadienone. To do so, we investigated 56 healthy individuals (thereof 29 females taking oral contraceptives) with two attention tasks on two consecutive days (once under androstadienone, once under placebo exposure in pseudorandomized order). With an emotional dot-probe task we measured visuo-spatial cueing while an emotional Stroop task allowed us to investigate interference control. Our results suggest that androstadienone acts in a sex, task and emotion-specific manner as a reduction in interference processes in the emotional Stroop task was only apparent for angry faces in men under androstadienone exposure. More specifically, men showed a smaller difference in reaction times for congruent compared to incongruent trials. At the same time also women were slightly affected by smelling androstadienone as they classified angry faces more often correctly under androstadienone. For the emotional dot-probe task no modulation by androstadienone was observed. Furthermore, in both attention paradigms individual sensitivity to androstadienone was neither correlated with reaction times nor error rates in men and women. To conclude, exposure to androstadienone seems to potentiate the relevance of angry faces in both men and women in connection with interference control, while processes of visuo-spatial cueing remain unaffected.

Sex-Related Differences in Emotion Recognition in Multi-concussed Athletes

OBJECTIVES

Concussion is defined as a complex pathophysiological process affecting the brain. Although the cumulative and long-term effects of multiple concussions are now well documented on cognitive and motor function, little is known about their effects on emotion recognition. Recent studies have suggested that concussion can result in emotional sequelae, particularly in females and multi-concussed athletes. The objective of this study was to investigate sex-related differences in emotion recognition in asymptomatic male and female multi-concussed athletes.

METHODS

We tested 28 control athletes (15 males) and 22 multi-concussed athletes (10 males) more than a year since the last concussion. Participants completed the Post-Concussion Symptom Scale, the Beck Depression Inventory-II, the Beck Anxiety Inventory, a neuropsychological test battery and a morphed emotion recognition task. Pictures of a male face expressing basic emotions (anger, disgust, fear, happiness, sadness, surprise) morphed with another emotion were randomly presented. After each face presentation, participants were asked to indicate the emotion expressed by the face.

RESULTS

Results revealed significant sex by group interactions in accuracy and intensity threshold for negative emotions, together with significant main effects of emotion and group.

CONCLUSIONS

Male concussed athletes were significantly impaired in recognizing negative emotions and needed more emotional intensity to correctly identify these emotions, compared to same-sex controls. In contrast, female concussed athletes performed similarly to same-sex controls. These findings suggest that sex significantly modulates concussion effects on emotional facial expression recognition. (JINS, 2017, 23, 65-77).

Affective responsiveness is influenced by intake of oral contraceptives

Despite the widespread use of oral contraceptive pills (OCs), little is known about their impact on psychological processes and emotional competencies. Recent data indicate impaired emotion recognition in OC users compared to naturally cycling females. Building upon these findings, the current study investigated the influence of OC use on three components of empathy, i.e., emotion recognition, perspective-taking, and affective responsiveness. We compared naturally cycling women to two groups of OC users, one being tested in their pill-free week and one in the phase of active intake. Whereas groups did not differ in emotion recognition and perspective-taking, an effect of pill phase was evident for affective responsiveness: Females currently taking the pill showed better performance than those in their pill-free week. These processing advantages complement previous findings on menstrual cycle effects and thereby suggest an association with changes in endogenous and exogenous reproductive hormones. The current study highlights the need for future research to shed more light on the neuroendocrine alterations accompanying OC intake.

A Preliminary Study of Sex Differences in Emotional Experience

Evolutionary approaches have proposed that women possess an advantage over men in emotional functioning to promote attachment for child-rearing. Likewise, sex differences have been reported in traits such as personality and empathy, traits that likely modulate emotional processing. In this preliminary study, sex differences in emotional processing were analyzed, including empathy as a social emotion and personality traits, as well as whether there exist relationships between those measures. Young volunteers ( N = 105) indicated the emotional valence, activation, and dominance that they experience in situations categorized as emotionally positive, negative, or neutral. The results of comparison between sexes supported the approach that women showed more sensitivity to high activation and dominance for positive emotions and empathy, and men were more sensitive to negative situations. Correlation analysis showed only one positive relationship between scores of Self-transcendence, a subscale of Temperament and Character Inventory, with activation scores of neutral situations, but not with emotionally charged situations, perhaps because emotions are context-dependent processes while personality traits are considered context-independent descriptions of habits. These findings should be replicated to enrich knowledge about problems in emotional processing.

Sex differences in social modulation of learning in rats

In its simplest form, empathy can be characterized as the capacity to share the emotional experiences among individuals, a phenomenon known as emotional contagion. Recent research shows that emotional contagion and its adaptive role can be studied in rodents. However, it is not known whether sex differences observed in human empathy extend to its more primitive forms. In the present study, we used a rat model of emotional contagion to compare the behavioral consequences of social transfer of information about threat, and the subsequent neural activation patterns in male and female rats. We found that: (1) males and females display a similar behavioral pattern during the interaction with either a fear-conditioned or a control rat; (2) interaction with a fear-conditioned conspecific positively modulates two-way avoidance learning in male and diestral female rats but not in estral females; and (3) such interaction results in increased c-Fos expression in the central and lateral nuclei of the amygdala and the prelimbic and infralimbic cortex in males, whereas in females no such changes were observed. Collectively, our results point to the occurrence of sex and estrus cycle phase differences in susceptibility to emotional contagion and underlying neuronal activation in rodents.

Progesterone mediates the late positive potentials evoked by affective pictures in high neuroticism females

BACKGROUND

Neuroticism, which is a personality trait characterized by the tendency to experience negative affect, is associated with premenstrual negative emotion changes. The present ERP study intended to investigate how neuroticism and the menstrual cycle influence the evaluation of emotion as a function of the tested levels of ovarian hormones.

METHOD

Forty-two healthy females with regular menstrual cycles were grouped by neuroticism (N): 16 were included in the high-N group, and 26 were included in the low-N group. Each female performed an emotion evaluation task in the early follicular phase, late follicular phase and luteal phase while the ERPs, hormone samples and Pleasure-Arousal-Dominance (PAD) mood ratings were measured.

RESULTS

The PAD and behavioral data did not differ between the two groups during the three phases. However, the mean amplitude of the Late Positive Potentials (LPP, 300-1000ms post-stimulus) of ERPs was significantly larger in the high-N group than that in the low-N group. Moreover, the interaction between the group and phase was significant 2000-4000ms post-stimulus: for the high-N group, the LPP of the luteal phase was the largest, followed by the late follicular phase and the early follicular phase; whereas the LPP of the luteal phase was the largest, followed by the early follicular phase and the late follicular phase for the low-N group. More importantly, the LPP (300-4000ms post-stimulus) evoked by positive pictures from the central or parietal area was significantly negatively correlated with the progesterone level in the early follicular phase.

CONCLUSIONS

The present study provides electrophysiological evidence showing that both the menstrual cycle and neuroticism modulate the LPP evoked by emotional pictures. Furthermore, the negative correlation between progesterone and the amplitude of the LPP suggests that the effect of the menstrual cycle on the LPP may be primarily a function of progesterone. These findings suggest that the LPP evoked by emotional pictures for high and low neuroticism females change throughout the menstrual cycle and that this change is in part mediated by progesterone.