Mariska E. Kret

A review on sex differences in processing emotional signals

Interest in sex-related differences in psychological functioning has again come to the foreground with new findings about their possible functional basis in the brain. Sex differences may be one way how evolution has capitalized on the capacity of homologous brain regions to process social information between men and women differently. This paper focuses specifically on the effects of emotional valence, sex of the observed and sex of the observer on regional brain activations. We also discuss the effects of and interactions between environment, hormones, genes and structural differences of the brain in the context of differential brain activity patterns between men and women following exposure to seen expressions of emotion and in this context we outline a number of methodological considerations for future research. Importantly, results show that although women are better at recognizing emotions and express themselves more easily, men show greater responses to threatening cues (dominant, violent or aggressive) and this may reflect different behavioral response tendencies between men and women as well as evolutionary effects. We conclude that sex differences must not be ignored in affective research and more specifically in affective neuroscience.

Standing up for the body. Recent progress in uncovering the networks involved in the perception of bodies and bodily expressions.

Recent studies of monkeys and humans have identified several brain regions that respond to bodies. Researchers have so far mainly addressed the same questions about bodies and bodily expressions that are already familiar from three decades of face and facial expression studies. Our present goal is to review behavioral, electrophysiological and neurofunctional studies on whole body and bodily expression perception against the background of what is known about face perception. We review all currently available evidence in more detail than done so far, but we also argue for a more theoretically motivated comparison of faces and bodies that reflects some broader concerns than only modularity or category specificity of faces or bodies.

Reviews and perspectivesA review on sex differences in processing emotional signals

Interest in sex-related differences in psychological functioning has again come to the foreground with new findings about their possible functional basis in the brain. Sex differences may be one way how evolution has capitalized on the capacity of homologous brain regions to process social information between men and women differently. This paper focuses specifically on the effects of emotional valence, sex of the observed and sex of the observer on regional brain activations. We also discuss the effects of and interactions between environment, hormones, genes and structural differences of the brain in the context of differential brain activity patterns between men and women following exposure to seen expressions of emotion and in this context we outline a number of methodological considerations for future research. Importantly, results show that although women are better at recognizing emotions and express themselves more easily, men show greater responses to threatening cues (dominant, violent or aggressive) and this may reflect different behavioral response tendencies between men and women as well as evolutionary effects. We conclude that sex differences must not be ignored in affective research and more specifically in affective neuroscience.

Similarities and differences in perceiving threat from dynamic faces and bodies. An fMRI study.

Neuroscientific research on the perception of emotional signals has mainly focused on how the brain processes threat signals from photographs of facial expressions. Much less is known about body postures or about the processing of dynamic images. We undertook a systematic comparison of the neurofunctional network dedicated to processing facial and bodily expressions. Two functional magnetic resonance imaging (fMRI) experiments investigated whether areas involved in processing social signals are activated differently by threatening signals (fear and anger) from facial or bodily expressions. The amygdala (AMG) was more active for facial than for bodily expressions. Body stimuli triggered higher activation than face stimuli in a number of areas. These were the cuneus, fusiform gyrus (FG), extrastriate body area (EBA), temporoparietal junction (TPJ), superior parietal lobule (SPL), primary somatosensory cortex (SI), as well as the thalamus. Emotion-specific effects were found in TPJ and FG for bodies and faces alike. EBA and superior temporal sulcus (STS) were more activated by threatening bodies.

Oxytocin-Motivated Ally Selection is Moderated by Fetal Testosterone Exposure and Empathic Concern.

In humans, the hypothalamic neuropeptide oxytocin shifts the individual’s focus on self-interest toward group-serving cognitions and decision-making. Here we examine this general tendency in the context of group formation, where individuals included into their group (or not) 18 targets morphed as having low or high-threat potential (with high-threat targets being beneficial to group-interests but potentially hurting the recruiter’s self-interest). Ninety healthy males self-administered oxytocin or placebo in a randomized double-blind, placebo-controlled study design, had their hands scanned to derive fetal testosterone vs. estradiol exposure from their 2D:4D ratio, and self-reported on their chronic empathic concern. Multilevel regression models revealed that when given oxytocin rather than placebo, individuals with low fetal testosterone priming included low-threat targets more and high-threat targets (somewhat) less. Individuals with high fetal testosterone (i.e., low estradiol) exposure, however, included high-threat targets more, and low-threat targets less when given oxytocin rather than placebo. Second, when given oxytocin rather than placebo, individuals with low empathic concern included low-threat targets more and high-threat targets less. Individuals with high empathic concern, however, included high-threat targets more, and low-threat targets less when given oxytocin rather than placebo. We conclude that oxytocin shifts the individual’s focus from self to group-serving cognition and decision-making, and that these tendencies are stronger for males with high rather than low fetal testosterone vs. estradiol exposure, and high rather than low empathic concern. Implications and avenues for future research are discussed.

Oxytocin conditions intergroup relations through upregulated in-group empathy, cooperation, conformity, and defense

Humans live in, rely on, and contribute to groups. Evolution may have biologically prepared them to quickly identify others as belonging to the in-group (vs. not), to decode emotional states, and to empathize with in-group members; to learn and conform to group norms and cultural practices; to extend and reciprocate trust and cooperation; and to aggressively protect the in-group against outside threat. We review evidence that these components of human group psychology rest on and are modulated by the hypothalamic neuropeptide oxytocin. It appears that oxytocin motivates and enables humans to 1) like and empathize with others in their groups, 2) comply with group norms and cultural practices, and 3) extend and reciprocate trust and cooperation, which may give rise to intergroup discrimination and sometimes defensive aggression against threatening (members of) out-groups. We explore the possibility that deficiencies in (components of) group psychology, seen in autistic spectrum disorder, schizophrenia, and borderline personality and social anxiety disorders, may be reduced by oxytocin administration. Avenues for new research are highlighted, and implications for the role of oxytocin in cooperation and competition within and between groups are discussed.

Perception of face and body expressions using electromyography, pupillometry and gaze measures.

Traditional emotion theories stress the importance of the face in the expression of emotions but bodily expressions are becoming increasingly important as well. In these experiments we tested the hypothesis that similar physiological responses can be evoked by observing emotional face and body signals and that the reaction to angry signals is amplified in anxious individuals. We designed three experiments in which participants categorized emotional expressions from isolated facial and bodily expressions and emotionally congruent and incongruent face-body compounds. Participants’ fixations were measured and their pupil size recorded with eye-tracking equipment and their facial reactions measured with electromyography. The results support our prediction that the recognition of a facial expression is improved in the context of a matching posture and importantly, vice versa as well. From their facial expressions, it appeared that observers acted with signs of negative emotionality (increased corrugator activity) to angry and fearful facial expressions and with positive emotionality (increased zygomaticus) to happy facial expressions. What we predicted and found, was that angry and fearful cues from the face or the body, attracted more attention than happy cues. We further observed that responses evoked by angry cues were amplified in individuals with high anxiety scores. In sum, we show that people process bodily expressions of emotion in a similar fashion as facial expressions and that the congruency between the emotional signals from the face and body facilitates the recognition of the emotion.

Social context influences recognition of bodily expressions

Previous studies have shown that recognition of facial expressions is influenced by the affective information provided by the surrounding scene. The goal of this study was to investigate whether similar effects could be obtained for bodily expressions. Images of emotional body postures were briefly presented as part of social scenes showing either neutral or emotional group actions. In Experiment 1, fearful and happy bodies were presented in fearful, happy, neutral and scrambled contexts. In Experiment 2, we compared happy with angry body expressions. In Experiment 3 and 4, we blurred the facial expressions of all people in the scene. This way, we were able to ascribe possible scene effects to the presence of body expressions visible in the scene and we were able to measure the contribution of facial expressions to the body expression recognition. In all experiments, we observed an effect of social scene context. Bodily expressions were better recognized when the actions in the scenes expressed an emotion congruent with the bodily expression of the target figure. The specific influence of facial expressions in the scene was dependent on the emotional expression but did not necessarily increase the congruency effect. Taken together, the results show that the social context influences our recognition of a person’s bodily expression.

The role of negative affectivity and social inhibition in perceiving social threat: an fMRI study.

Personality is associated with specific emotion regulation styles presumably linked with unique brain activity patterns. By using functional magnetic resonance imaging (fMRI) in 26 individuals, the neural responses to threatening (fearful and angry) facial and bodily expressions were investigated in relation to negative affectivity and social inhibition. A negative correlation was observed between negative affectivity and activation of the amygdala, fusiform gyrus, insula and hippocampus. Increased activation following threatening stimuli was observed in the left temporo-parietal junction and right extrastriate body area correlating with more social inhibition traits. Interestingly, the orbitofrontal cortex, superior temporal sulcus, inferior frontal gyrus (Brodmann area 45) and temporal pole correlated negatively with negative affectivity and positively with social inhibition. Whereas individuals with increased negative affectivity tend to de-activate the core emotion system, socially inhibited people tend to over-activate a broad cortical network. Our findings demonstrate effects of personality traits on the neural coding of threatening signals.

Men Fear Other Men Most: Gender Specific Brain Activations in Perceiving Threat from Dynamic Faces and Bodies – An fMRI Study

Gender differences are an important factor regulating our daily interactions. Using functional magnetic resonance imaging we show that brain areas involved in processing social signals are activated differently by threatening signals send from male and female facial and bodily expressions and that their activation patterns are different for male and female observers. Male participants pay more attention to the female face as shown by increased amygdala activity. But a host of other areas show selective sensitivity for male observers attending to male threatening bodily expressions (extrastriate body area, superior temporal sulcus, fusiform gyrus, pre-supplementary motor area, and premotor cortex). This is the first study investigating gender differences in processing dynamic female and male facial and bodily expressions and it illustrates the importance of gender differences in affective communication.