Specialization of amygdala subregions in emotion processing

The amygdala is important for human fear processing. However, recent research has failed to reveal specificity, with evidence that the amygdala also responds to other emotions. A more nuanced understanding of the amygdala's role in emotion processing, particularly relating to fear, is needed given the importance of effective emotional functioning for everyday function and mental health. We studied 86 healthy participants (44 females), aged 18-49 (mean 26.12 ± 6.6) years, who underwent multiband functional magnetic resonance imaging. We specifically examined the reactivity of four amygdala subregions (using regions of interest analysis) and related brain connectivity networks (using generalized psycho-physiological interaction) to fear, angry, and happy facial stimuli using an emotional face-matching task. All amygdala subregions responded to all stimuli (p-FDR < .05), with this reactivity strongly driven by the superficial and centromedial amygdala (p-FDR < .001). Yet amygdala subregions selectively showed strong functional connectivity with other occipitotemporal and inferior frontal brain regions with particular sensitivity to fear recognition and strongly driven by the basolateral amygdala (p-FDR < .05). These findings suggest that amygdala specialization to fear may not be reflected in its local activity but in its connectivity with other brain regions within a specific face-processing network.

Resting-state amygdala subregion and precuneus connectivity provide evidence for a dimensional approach to studying social anxiety disorder

Social anxiety disorder (SAD) is a prevalent and disabling mental health condition, characterized by excessive fear and anxiety in social situations. Resting-state functional magnetic resonance imaging (fMRI) paradigms have been increasingly used to understand the neurobiological underpinnings of SAD in the absence of threat-related stimuli. Previous studies have primarily focused on the role of the amygdala in SAD. However, the amygdala consists of functionally and structurally distinct subregions, and recent studies have highlighted the importance of investigating the role of these subregions independently. Using multiband fMRI, we analyzed resting-state data from 135 participants (42 SAD, 93 healthy controls). By employing voxel-wise permutation testing, we examined group differences of fMRI connectivity and associations between fMRI connectivity and social anxiety symptoms to further investigate the classification of SAD as a categorical or dimensional construct. Seed-to-whole brain functional connectivity analysis using multiple 'seeds' including the amygdala and its subregions and the precuneus, revealed no statistically significant group differences. However, social anxiety severity was significantly negatively correlated with functional connectivity of the precuneus - perigenual anterior cingulate cortex and positively correlated with functional connectivity of the amygdala (specifically the superficial subregion) - parietal/cerebellar areas. Our findings demonstrate clear links between symptomatology and brain connectivity in the absence of diagnostic differences, with evidence of amygdala subregion-specific alterations. The observed brain-symptom associations did not include disturbances in the brain's fear circuitry (i.e., disturbances in connectivity between amygdala - prefrontal regions) likely due to the absence of threat-related stimuli.

EEG-Meta-Microstates: Towards a More Objective Use of Resting-State EEG Microstate Findings Across Studies

Over the last decade, EEG resting-state microstate analysis has evolved from a niche existence to a widely used and well-accepted methodology. The rapidly increasing body of empirical findings started to yield overarching patterns of associations of biological and psychological states and traits with specific microstate classes. However, currently, this cross-referencing among apparently similar microstate classes of different studies is typically done by "eyeballing" of printed template maps by the individual authors, lacking a systematic procedure. To improve the reliability and validity of future findings, we present a tool to systematically collect the actual data of template maps from as many published studies as possible and present them in their entirety as a matrix of spatial similarity. The tool also allows importing novel template maps and systematically extracting the findings associated with specific microstate maps from ongoing or published studies. The tool also allows importing novel template maps and systematically extracting the findings associated with specific microstate maps in the literature. The analysis of 40 included sets of template maps indicated that: (i) there is a high degree of similarity of template maps across studies, (ii) similar template maps were associated with converging empirical findings, and (iii) representative meta-microstates can be extracted from the individual studies. We hope that this tool will be useful in coming to a more comprehensive, objective, and overarching representation of microstate findings.

Normalized affective responsiveness following deep brain stimulation of the medial forebrain bundle in depression

Deep brain stimulation (DBS) of the supero-lateral medial forebrain bundle (slMFB) is associated with rapid and sustained antidepressant effects in treatment-resistant depression (TRD). Beyond that, improvements in social functioning have been reported. However, it is unclear whether social skills, the basis of successful social functioning, are systematically altered following slMFB DBS. Therefore, the current study investigated specific social skills (affective empathy, compassion, and theory of mind) in patients with TRD undergoing slMFB DBS in comparison to healthy subjects. 12 patients with TRD and 12 age- and gender-matched healthy subjects (5 females) performed the EmpaToM, a video-based naturalistic paradigm differentiating between affective empathy, compassion, and theory of mind. Patients were assessed before and three months after DBS onset and compared to an age- and gender-matched sample of healthy controls. All data were analyzed using non-parametric Mann-Whitney U tests. DBS treatment significantly affected patients' affective responsiveness towards emotional versus neutral situations (i.e. affective empathy): While their affective responsiveness was reduced compared to healthy subjects at baseline, they showed normalized affective responsiveness three months after slMFB DBS onset. No effects occurred in other domains with persisting deficits in compassion and intact socio-cognitive skills. Active slMFB DBS resulted in a normalized affective responsiveness in patients with TRD. This specific effect might represent one factor supporting the resumption of social activities after recovery from chronic depression. Considering the small size of this unique sample as well as the explorative nature of this study, future studies are needed to investigate the robustness of these effects.

Social high performers under stress behave more prosocially and detect happy emotions better in a male sample

Psychosocial stress is increasing in society, impacting our lives in all social domains. However, the conditions under which stress facilitates ("tend-and-befriend") or hinders ("fight-or-flight") social approach remain elusive. We tested whether previous heterogeneous findings might be resolved by accounting for individual differences in social performance under stress. For that purpose, we introduce the novel Trier Social Stress Test (TSST) social performance index that was aggregated across ratings from two independent observers. Moreover, we apply an innovative setup enabling electroencephalographic (EEG) data to be measured inside an electrically-shielded cabin during stress, namely the TSST-EEG. Relying on a sample of 59 healthy male participants, we collected behavioral (i.e., sharing resources with others) and cognitive (i.e., detecting facial emotional expressions) approach patterns while participants experienced either acute psychosocial stress (n = 31) or no stress (control condition; n = 28) and while EEG was being recorded. During stress exposure, high-performing participants behaved more prosocially, and differentiated better between happy and neutral emotions on both behavioral and neurophysiological levels (revealed by intensity differences in a N170-like response). Overall, our findings demonstrate the added value of both the novel TSST social performance index and the novel TSST-EEG setup. By showing that high social performance during the TSST is associated with behavioral, cognitive, and neurophysiological approach patterns, our study offers valuable insights into adaptive or maladaptive psychobiological mechanisms in coping with psychosocial stress. Future stress research should address the role of social performance differences during stress in social interaction to better understand the behavioral consequences of psychosocial stress in humans.

Oxytocin in response to MDMA provocation test in patients with arginine vasopressin deficiency (central diabetes insipidus): a single-centre, case-control study with nested, randomised, double-blind, placebo-controlled crossover trial

BACKGROUND

Disruptions of the hypothalamic-pituitary axis can cause an arginine vasopressin deficiency, also known as central diabetes insipidus. Patients with this condition are at high risk of additional oxytocin deficiency owing to the close anatomical proximity of oxytocin-producing neurons; however, no conclusive evidence for such a deficiency has been reported. We aimed to use 3,4-methylenedioxymethamphetamine (MDMA, also known as ecstasy), a strong activator of the central oxytocinergic system, as a biochemical and psychoactive provocation test to investigate oxytocin deficiency in patients with arginine vasopressin deficiency (central diabetes insipidus).

METHODS

This single-centre, case-control study with nested, randomised, double-blind, placebo-controlled crossover trial included patients with arginine vasopressin deficiency (central diabetes insipidus) and healthy controls (matched 1:1 by age, sex, and BMI) and was conducted at the University Hospital Basel, Basel, Switzerland. We used block randomisation to assign participants to receive either a single oral dose of MDMA (100 mg) or placebo in the first experimental session; patients received the opposite treatment at the next session, with a wash-out period of at least 2 weeks between the two sessions. Participants and investigators assessing the outcomes were masked to assignment. Oxytocin concentrations were measured at 0, 90, 120, 150, 180, and 300 min after MDMA or placebo. The primary outcome was the area under the plasma oxytocin concentration curve (AUC) after drug intake. The AUC was compared between groups and conditions using a linear mixed-effects model. Subjective drug effects were assessed throughout the study using ten-point visual analogue scales. Acute adverse effects were assessed before and 360 min after drug intake using a 66-item list of complaints. This trial is registered with ClinicalTrials.gov, NCT04648137.

FINDINGS

Between Feb 1, 2021, and May 1, 2022, we recruited 15 patients with arginine vasopressin deficiency (central diabetes insipidus) and 15 healthy controls. All participants completed the study and were included in the analyses. In healthy controls, median plasma oxytocin concentration was 77 pg/mL (IQR 59-94) at baseline and increased by 659 pg/mL (355-914) in response to MDMA, resulting in an AUC of 102 095 pg/mL (41 782-129 565); in patients, baseline oxytocin concentration was 60 pg/mL (51-74) and only slightly increased by 66 pg/mL (16-94) in response to MDMA, resulting in an AUC of 6446 pg/mL (1291-11 577). The effect of MDMA on oxytocin was significantly different between groups: the AUC for oxytocin was 82% (95% CI 70-186) higher in healthy controls than in patients (difference 85 678 pg/mL [95% CI 63 356-108 000], p<0·0001). The increase in oxytocin in healthy controls was associated with typical strong subjective prosocial, empathic, and anxiolytic effects, whereas only minimal subjective effects were observed in patients, in agreement with the lack of increase in oxytocin concentrations. The most frequently reported adverse effects were fatigue (eight [53%] healthy controls and eight [53%] patients), lack of appetite (ten [67%] healthy controls and eight [53%] patients), lack of concentration (eight [53%] healthy controls and seven [47%] patients), and dry mouth (eight [53%] healthy controls and eight [53%] patients). In addition, two (13%) healthy controls and four (27%) patients developed transient mild hypokalaemia.

INTERPRETATION

These findings are highly suggestive of clinically meaningful oxytocin deficiency in patients with arginine vasopressin deficiency (central diabetes insipidus), laying the groundwork for a new hypothalamic-pituitary disease entity.

FUNDING

Swiss National Science Foundation, Swiss Academy of Medical Sciences, and the G&J Bangerter-Rhyner Foundation.

Impairment in reading negative social cues extends beyond the face in autism

Nonverbal expressions are essential to regulating social communication and interaction. Impaired emotion recognition from facial expressions has been linked to various psychiatric conditions characterized by severe social deficits such as autism. As body expressions as an additional source of social-emotional information have attracted little research attention, little is known about whether emotion recognition impairments are specific to faces, or extend to body expressions. This study explored and compared emotion recognition from face versus body expressions in autism spectrum disorder. We compared 30 men with autism spectrum disorder to 30 male age- and IQ-matched control participants in their ability to recognize angry, happy, and neutral expressions from dynamic face and body expressions. Participants with autism spectrum disorder showed impaired recognition of angry expressions from both faces and bodies, while there were no group differences in recognizing happy and neutral expressions. In autism spectrum disorder, recognizing angry face expressions was inversely predicted by gaze avoidance, while recognizing angry body expressions was inversely predicted by impairments in social interaction and autistic traits. These findings suggest that distinct mechanisms may underlie the impaired emotion recognition from face and body expressions in autism spectrum disorder, respectively. Overall, our study demonstrates that emotion-specific recognition difficulties in autism spectrum disorder are not limited to face expressions but extend to emotional body expressions.

Reduced eye gaze during facial emotion recognition in chronic depression: Effects of intranasal oxytocin

Chronic depression disorders (CDD) are characterized by impaired social cognitive functioning. Visual attention during social perception is altered in clinical depression and is known to be sensitive to intranasal treatment with oxytocin (OT). The present study thus investigated potential alterations in gaze preferences during a standardized facial emotion recognition (FER) task using remote eye tracking in patients with CDD and the effect of a single dose of intranasal OT (compared to placebo). In emotion recognition, CDD patients were not more impaired than healthy controls, and there was no OT effect. However, CDD patients (with placebo) demonstrated less attentional preference for the eye region during FER than healthy controls, which was not apparent in the CDD group after OT treatment. Our results suggest that despite largely preserved basic facial emotions recognition, attention in social perception may be altered in CDD, and that this bias may be sensitive to OT treatment. These findings highlight OTs potential as a means of augmenting psychotherapy.

Effects of intranasal oxytocin and positive couple interaction on immune factors in skin wounds

BACKGROUND

Intimate social relationships improve individual health and longevity, an effect which is supposed to be mediated through stress-sensitive endocrine and immune mechanisms in response to positive interaction behavior. On a neuroendocrine level, oxytocin (OT) buffers stress responses, modulates social attachment behavior and has been associated with cytokine expression. Consequently, the aim of the present study was to investigate instructed positive couple interaction, observed behavior, and OT in their effect on immune function.

METHODS

In a 4-group design, 80 healthy couples (N = 160 individuals) received four standard dermal suction blister wounds and were randomized to instructed positive interaction/control and intranasal OT/placebo. Unstimulated cytokines (IL-1β, IL-6, TNF-α) were assessed from wound liquid at 40 min, 105 min and 24 hrs after wounding.

RESULTS

Overall, group assignment did not affect friendly or dominant behavior during the interaction sequence. IL-1β and IL-6 levels, however, were moderated by group assignment with lowest levels in women in the positive interaction and OT condition in IL-1 and highest levels in IL-6. TNF-α responses to wounding were not affected from group assignment, however observed friendliness in women was associated with lower TNF-α levels.

DISCUSSION

These findings support the immune-regulating role of friendly behavior in romantic couples. Above this, the data provide the first empirical evidence that an intervention that simultaneously targets neuroendocrine mediators and behavior could affect immune function in a sex specific manner and with potential long-term health relevance.

No evidence that gaze anxiety predicts gaze avoidance behavior during face-to-face social interaction

Eye contact is an indispensable social signal, yet for some individuals it is also a source of discomfort they fear and avoid. However, it is still unknown whether gaze anxiety actually produces avoidant gaze behavior in naturalistic, face-to-face interactions. Here, we relied on a novel dual eye-tracking setup that allows us to assess interactive gaze behavior. To investigate the effect of gaze anxiety on gaze behavior, we a priori created groups of participants reporting high or low levels of gaze anxiety. These participants (n = 51) then performed a semi-standardized interaction with a previously unknown individual reporting a medium level of gaze anxiety. The gaze behavior of both groups did not differ in either classical one-way, eye-tracking parameters (e.g. unilateral eye gaze), or interactive, two-way ones (e.g. mutual gaze). Furthermore, the subjective ratings of both participants' interaction did not differ between groups. Gaze anxious individuals seem to exhibit normal gaze behavior which does not hamper the perceived quality of interactions in a naturalistic face-to-face setup. Our findings point to the existence of cognitive distortions in gaze anxious individuals whose exterior behavior might be less affected than feared by their interior anxiety.

A Self-Controlled Mind Is Reflected by Stable Mental Processing

Self-control-the ability to inhibit inappropriate impulses-predicts economic, physical, and psychological well-being. However, recent findings demonstrate low correlations among self-control measures, raising the question of what self-control actually is. Here, we examined the idea that people high in self-control show more stable mental processing, characterized by processing steps that are fewer in number but longer lasting because of fewer interruptions by distracting impulses. To test this hypothesis, we relied on resting electroencephalography microstate analysis, a method that provides access to the stream of mental processing by assessing the sequential activation of neural networks. Across two samples (Study 1: N = 58 male adults from Germany; Study 2: N = 101 adults from Canada, 58 females), the temporal stability of resting networks (i.e., longer durations and fewer occurrences) was positively associated with self-reported self-control and a neural index of inhibitory control, and it was negatively associated with risk-taking behavior. These findings suggest that stable mental processing represents a core feature of a self-controlled mind.

Impaired socio-affective, but intact socio-cognitive skills in patients with treatment-resistant, recurrent depression

BACKGROUND

Social withdrawal is a key symptom of depression. The resulting loss of social reinforcement in turn contributes to chronic, recurrent courses of the disease. However, it is not clear whether depressed patients have less motivation to socially interact, or whether their skills in doing so are impaired. The current study investigates potential skill deficits in patients with treatment-resistant depression (TRD).

METHODS

15 TRD patients and 19 age- and sex-matched healthy controls performed the EmpaToM, a paradigm which includes naturalistic video stimuli of either neutral or emotional valence and which differentiates between socio-affective (affective empathy, compassion) and socio-cognitive (theory of mind) skills.

RESULTS

Controlling for the baseline affective state in neutral situations, TRD patients displayed significantly reduced affective empathy towards emotional situations compared to healthy controls. Furthermore, TRD patients were less compassionate in both neutral and emotional situations. In contrast, socio-cognitive skill performances did not differ between patients and healthy controls.

LIMITATIONS

Further studies might explore socio-affective and socio-cognitive skills in TRD patients using socio-affective/-cognitive tasks involving face-to-face social interactions.

CONCLUSION

Our study revealed a specific socio-affective deficit in TRD patients, while showing intact socio-cognitive skills. Patients were less able to affectively resonate with others (affective empathy) and exhibited generally reduced feelings of compassion. These deficits might interfere with providing and receiving social support. Our study contributes to a better understanding of the underlying causes of social withdrawal and stresses the need to specifically address pervasive socio-affective deficits in psychotherapy of TRD patients.

Empathy Modulates the Effects of Acute Stress on Anxious Appearance and Social Behavior in Social Anxiety Disorder

Patients suffering from social anxiety disorder (SAD) fear social interaction and evaluation, which severely undermines their everyday life. There is evidence of increased prosocial behavior after acute social stress exposure in healthy individuals, which may be interpreted as stress-regulating "tend-and-befriend" behavior. In a randomized controlled trial, we measured empathic abilities in a first diagnostic session. In the following experimental session, we investigated how patients with SAD (n = 60) and healthy control participants (HC) (n = 52) respond to an acute social stressor (Trier Social Stress Test for groups) or a non-stressful control condition, and whether empathic abilities and acute social stress interact to modulate anxious appearance and social behavior in a social conversation test. Salivary cortisol, heart rate, and subjective stress response were repeatedly measured. The anxious appearance and social behavior of participants were rated by the conversation partner. SAD patients demonstrated stronger subjective stress responses while the biological responses did not differ from HC. Moreover, patients performed worse overall in the conversation task, which stress additionally undermined. Finally, we found that both emotional and cognitive empathy buffered the negative effects of acute stress on social behavior in SAD, but not in HC. Our data highlight the importance of empathic abilities for SAD during stressful situations and call for multimodal clinical diagnostics. This may help to differentiate clinical subtypes and offer better-tailored treatment for patients. General Scientific Summary: This study shows that high levels of cognitive and emotional empathy can buffer the negative effects of acute stress on social behavior in social anxiety disorder (SAD). Empathic abilities may be included as an additional diagnostic resource marker for SAD.

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.

Acute alcohol intoxication modulates the temporal dynamics of resting electroencephalography networks

This study aimed to provide a currently missing link between general intoxication-induced changes in overall brain activity and the multiple cognitive control deficits typically observed during acute alcohol intoxication. For that purpose, we analyzed the effects of acute alcohol intoxication (1.1‰) on the four archetypal electroencephalography (EEG) resting networks (i.e., microstates A-D) and their temporal dynamics (e.g., coverage and transitions from one microstate to another), as well as on self-reported resting-state cognition in n = 22 healthy young males using a counterbalanced within-subject design. Our microstate analyses indicated that alcohol increased the coverage of the visual processing-related microstate B at the expense of the autonomic processing-related microstate C. Add-on exploratory analyses revealed that alcohol increased transitions from microstate C to microstate B and decreased bidirectional transitions between microstate C and the attention-related microstate D. In line with the observed alcohol-induced decrease of the autonomic processing-related microstate C, participants reported decreases of their somatic awareness during intoxication, which were positively associated with more transitions from microstate C to microstate B. In sum, the observed effects provide mechanistic insights into how alcohol might hamper cognitive processing by generally prioritizing the bottom-up processing of visual stimuli over top-down internal information processing. The fact that this was found during the resting state further proves that alcohol-induced changes in brain activity are continuously present and do not only emerge during demanding situations or tasks.

Oxytocin Receptor Gene DNA Methylation: A Biomarker of Treatment Response in Obsessive-Compulsive Disorder?

INTRODUCTION

Obsessive-compulsive disorder (OCD) is associated with high chronicity and treatment resistance, indicating the need for early therapy response markers enabling fast and personalized treatment adaptations. Although epigenetic mechanisms such as DNA methylation of the oxytocin receptor (OXTR) gene have previously been linked to OCD pathogenesis, epigenetic markers as predictors of treatment success have not yet been investigated in OCD.

OBJECTIVE

For the first time, this therapyepigenetic study aimed to investigate the role of OXTR methylation as a treatment response marker in OCD.

METHODS

In total, 113 inpatients with OCD (57 females) were compared to 113 age- and sex-matched healthy controls. Patients were investigated over a 10-week course of standardized, OCD-specific cognitive-behavioral psychotherapy. Clinical response was measured using the Yale-Brown Obsessive Compulsive Scale (Y-BOCS) at baseline, before in vivo exposure, and after therapy. OXTR exon III methylation was analyzed via direct sequencing of sodium bisulfite-treated DNA extracted from blood cells.

RESULTS

Relative OXTR hypermethylation was observed in OCD patients compared to healthy controls. In OCD, higher baseline OXTR methylation was found to predict impaired treatment response at both categorical (responders vs. nonresponders) and dimensional (relative Y-BOCS reduction) levels, whereas lower baseline methylation was related to treatment response and greater symptom improvements. Analysis of Y-BOCS subdimensions revealed that the association between OXTR hypermethylation with impaired treatment response applied especially to symptoms related to obsessions, but not compulsions.

CONCLUSIONS

OXTR hypermethylation may constitute a predictive marker of impaired treatment response in OCD and thus carries great potential for future personalized treatment efforts in OCD.

The effect of attachment security priming and oxytocin on physiological responses to trauma films and subsequent intrusions

To further understand protective mechanisms to prevent post-traumatic stress disorder or assist recovery from psychological trauma, this study investigated whether pharmacological and psychological activation of a secure attachment representation elicits higher felt-security and a related response pattern of reduced physiological arousal and increased parasympathetic activation; and whether it protects individuals from developing intrusions and experiencing distress in the week following exposure to a trauma film. Using a double-blind, experimental mixed factorial design, 101 volunteers received either oxytocin or placebo and either secure attachment or neutral priming before watching a trauma film. We measured felt security as an indicator of the strength of activation of a secure attachment representation, skin conductance and heart rate as indicators of physiological arousal, and high frequency heart rate variability as an indicator of parasympathetic activation during the priming and the film. Participants then completed a seven-day intrusion diary. Secure attachment priming, but not oxytocin administration or the combination of both, was associated with reduced physiological arousal and increased parasympathetic activity during priming. Although secure attachment priming was not related to the absolute number of intrusions or to less perceived distress or physiological arousal during the trauma film, it was associated with lower intrusion-related distress in the 7-days post-testing. Our findings extend previous research that suggests the importance of interventions that address intrusion-related distress for recovery from trauma, and suggest a promising role for secure attachment priming in trauma-focused psychological therapies. We contribute to the growing literature that finds that higher subjective distress during a trauma is associated with higher intrusion-related distress. We discuss theoretical implications and possible mechanisms through which secure attachment priming may exert potential beneficial effects.

Oxytocin and positive couple interaction affect the perception of wound pain in everyday life

A large body of animal and human laboratory research has linked social interaction and support to pain perception, with a possible role for the neuropeptide oxytocin as a neuroendocrine mediator. However so far, it has been unclear whether these effects translate to ecologically valid everyday life behavior and pain perception. In a randomized placebo-controlled study, a standard suction blister skin wound was induced to N = 80 romantic couples (N = 160 individuals). Couples then received intranasal oxytocin or placebo twice daily and were either instructed to perform a positive social interaction (partner appraisal task, PAT) once in the laboratory and two times during the following five days, or not. During these days, all participants reported their subjective pain levels multiple times a day using ecologically momentary assessment. Results from hierarchical linear modeling suggest that pain levels within the couples were inter-related. In men, but not in women, oxytocin reduced pain levels. Women reported lower pain levels in the group of positive social interaction, while this effect did not show in men. These results suggest that intranasal oxytocin might have sex-specific effects with pain reducing effects in men but the opposite effects in women. In contrast, especially women benefit from positive interaction in terms of dampened pain levels after positive interaction. The results add to the evidence for health-beneficial effects of positive couple interaction and point to underlying neuroendocrine mechanisms in everyday life pain specifically. The sex-specific effects, in particular, may have implications for psychopharmacological treatment of pain in men and women.

Evaluation of an eye tracking setup for studying visual attention in face-to-face conversations

Many eye tracking studies use facial stimuli presented on a display to investigate attentional processing of social stimuli. To introduce a more realistic approach that allows interaction between two real people, we evaluated a new eye tracking setup in three independent studies in terms of data quality, short-term reliability and feasibility. Study 1 measured the robustness, precision and accuracy for calibration stimuli compared to a classical display-based setup. Study 2 used the identical measures with an independent study sample to compare the data quality for a photograph of a face (2D) and the face of the real person (3D). Study 3 evaluated data quality over the course of a real face-to-face conversation and examined the gaze behavior on the facial features of the conversation partner. Study 1 provides evidence that quality indices for the scene-based setup were comparable to those of a classical display-based setup. Average accuracy was better than 0.4° visual angle. Study 2 demonstrates that eye tracking quality is sufficient for 3D stimuli and robust against short interruptions without re-calibration. Study 3 confirms the long-term stability of tracking accuracy during a face-to-face interaction and demonstrates typical gaze patterns for facial features. Thus, the eye tracking setup presented here seems feasible for studying gaze behavior in dyadic face-to-face interactions. Eye tracking data obtained with this setup achieves an accuracy that is sufficient for investigating behavior such as eye contact in social interactions in a range of populations including clinical conditions, such as autism spectrum and social phobia.

Temporal dynamics of resting EEG networks are associated with prosociality

As prosociality is key to facing many of our societies' global challenges (such as fighting a global pandemic), we need to better understand why some individuals are more prosocial than others. The present study takes a neural trait approach, examining whether the temporal dynamics of resting EEG networks are associated with inter-individual differences in prosociality. In two experimental sessions, we collected 55 healthy males' resting EEG, their self-reported prosocial concern and values, and their incentivized prosocial behavior across different reward domains (money, time) and social contexts (collective, individual). By means of EEG microstate analysis we identified the temporal coverage of four canonical resting networks (microstates A, B, C, and D) and their mutual communication in order to examine their association with an aggregated index of prosociality. Participants with a higher coverage of microstate A and more transitions from microstate C to A were more prosocial. Our study demonstrates that temporal dynamics of intrinsic brain networks can be linked to complex social behavior. On the basis of previous findings on links of microstate A with sensory processing, our findings suggest that participants with a tendency to engage in bottom-up processing during rest behave more prosocially than others.

Glucocorticoids and cortical decoding in the phobic brain

Glucocorticoids reduce phobic fear in anxiety disorders and enhance psychotherapy, possibly by reducing the retrieval of fear memories and enhancing the consolidation of new corrective memories. Glucocorticoid signaling in the basolateral amygdala can influence connected fear and memory-related cortical regions, but this is not fully understood. Previous studies investigated specific pathways moderated by glucocorticoids, for example, visual-temporal pathways; however, these analyses were limited to a-priori selected regions. Here, we performed whole-brain pattern analysis to localize phobic stimulus decoding related to the fear-reducing effect of glucocorticoids. We reanalyzed functional magnetic resonance imaging (fMRI) data from a previously published study with spider-phobic patients and healthy controls. The patients received glucocorticoids or a placebo before the exposure to spider images. There was moderate evidence that patients with phobia had higher decoding of phobic content in the anterior cingulate cortex (ACC) and the left and right anterior insula compared to controls. Decoding in the ACC and the right insula showed strong evidence for correlation with experienced fear. Patients with cortisol reported a reduction of fear by 10-13%; however, there was only weak evidence for changes in neural decoding compared to placebo which was found in the precuneus, the opercular cortex, and the left cerebellum.

The mediating role of KITLG DNA methylation in the association between childhood adversity and cortisol stress reactivity does not replicate in monocytes

Adverse childhood experiences such as maltreatment or neglect are associated with mental health problems in adulthood. Changes in the regulation of the psychological and physiological stress reaction, mediated via epigenetic modifications, are discussed as potential mechanisms. This study aimed to replicate the role of DNA methylation of the KITLG gene in mediating the association between childhood adversity and stress-induced cortisol reactivity in a sample of adults reporting childhood adversity and a matched control group (N = 60). DNA was extracted from purified CD14⁺ monocytes and genome-wide DNA methylation was assessed with the 450k BeadChip for targeted replication and exploratory analyses. As previously reported, childhood adversity was associated with significantly lower cortisol reactivity to stress. We could neither replicate the association between KITLG DNA methylation and cortisol stress reactivity nor the association with childhood adversity. Moreover, DNA methylation of the target CpG (cg27512205) was not associated with KITLG mRNA expression in monocytes. Exploratory analyses of array-wide DNA methylation patterns showed no significant results for individual sites after correction for multiple testing - neither in association with childhood trauma nor with adult cortisol stress reactivity. The analysis of differentially methylated regions (DMRs) revealed two significant regions which both mapped to non-coding genes in the association with cortisol stress reactivity. The mediating role of DNA methylation of the KITLG locus in the association between childhood adversity and cortisol stress reactivity could not be replicated in monocytes. In addition to differences in investigated tissue, reasons for non-replication might include differences between samples in age, ethnicity, trauma severity, and cortisol reactivity.

A global database of Holocene paleotemperature records

A comprehensive database of paleoclimate records is needed to place recent warming into the longer-term context of natural climate variability. We present a global compilation of quality-controlled, published, temperature-sensitive proxy records extending back 12,000 years through the Holocene. Data were compiled from 679 sites where time series cover at least 4000 years, are resolved at sub-millennial scale (median spacing of 400 years or finer) and have at least one age control point every 3000 years, with cut-off values slackened in data-sparse regions. The data derive from lake sediment (51%), marine sediment (31%), peat (11%), glacier ice (3%), and other natural archives. The database contains 1319 records, including 157 from the Southern Hemisphere. The multi-proxy database comprises paleotemperature time series based on ecological assemblages, as well as biophysical and geochemical indicators that reflect mean annual or seasonal temperatures, as encoded in the database. This database can be used to reconstruct the spatiotemporal evolution of Holocene temperature at global to regional scales, and is publicly available in Linked Paleo Data (LiPD) format.

The Trust Game for Couples (TGC): A new standardized paradigm to assess trust in romantic relationships

Trust between couples is a prerequisite for stable and satisfactory romantic relationships. However, there has been no valid research tool to assess partner-specific trust behavior including costly investments in the trustworthiness of the romantic partner. We here present a comprehensive validation of the newly developed Trust Game for Couples (TGC) by means of various self-report and implicit relationship-related measures. The TGC operationalizes trust by measuring an individual's willingness to invest his or her own financial resources in pro-relationship attitudes of their romantic partner (collected by dichotomous responses to relationship-relevant items, e.g., answering yes to "I am absolutely sure that I love my partner"). Thirty-five healthy couples between 20 and 34 years completed the TGC in an interactive (both partners present), but anonymous setting (no information on the partner's responses revealed). Trust, as measured by the TGC, correlates positively with self-reported trust, satisfaction, and felt closeness in the relationship, but not with general interpersonal trust, confirming both its convergent and discriminant validity. In addition to explicit criteria for construct validity, implicit measures of partner valence and confidence explained variance in the TGC, demonstrating that it constitutes an economical measure of implicit and explicit ingredients of trust between couples. In sum, the TGC provides a novel, specific behavioral tool for a sensitive assessment of trust in dyadic relationships with potential for numerous research fields.

Oxytocin changes behavior and spatio-temporal brain dynamics underlying inter-group conflict in humans

Inter-group conflicts drive human discrimination, mass migration, and violence, but their psychobiological mechanisms remain largely unknown. Here, we investigated whether the neuropeptide oxytocin modulates behavior and spatio-temporal brain dynamics in naturalistic inter-group conflict. Eighty-six male members of natural rival social groups received either oxytocin or placebo intranasally. In a decision-making paradigm involving real monetary stakes, participants could sacrifice their own resources to modulate the monetary gains and losses of in- and out-group members. Oxytocin eliminated the reduction in out-group gains - particularly in individuals with low emotional empathy, whereas those given placebo exhibited this negative social behavior. Our spatio-temporal analysis of event-related potentials elicited by outcome valuation revealed that oxytocin replaced a neurophysiological process associated with the negative valuation of out-group gains via a process associated with positive valuation between 200-500ms after outcome presentation. Oxytocin thus seems to modulate inter-group behavior in humans via a specific alteration of valuation-related brain dynamics.

Effects of a 6-Week Internet-Based Stress Management Program on Perceived Stress, Subjective Coping Skills, and Sleep Quality

Occupational stress management intervention programs are known to be effective in preventing stress-related health burden. Two essential mechanisms underlie this effect: (i) a reduction in perceived stress (e.g., via relaxation-oriented techniques), and (ii) an improvement in coping skills (e.g., via cognitive-behavioral interventions). While relaxation-oriented interventions are more frequently employed in occupational settings, cognitive-behavioral stress management interventions reveal stronger effects on stress-related outcomes. As an effective and economic strategy, the dissemination of stress management programs via the internet is soaring, but most internet-based programs focus on relaxation or reducing perceived stress. In the present study, we examined the effects of a self-guided, cognitive-behavioral 6-week Internet-Based Stress Management (IBSM) program on perceived stress, coping skills, emotional exhaustion, depressive symptoms, and sleep quality. The IBSM consists of six modules focusing on the improvement of stress management skills such as dealing with acute stress, building up resources, or reappraising stress-facilitating cognitions. The participants have to work through the content on a weekly basis, requiring about 30 min per week followed by a transfer task lasting another 30 min. Healthy employees reporting elevated stress were recruited over the Internet and then randomly assigned to the IBSM group or a waiting list control group. A total of 134 participants completed all assessments before and after the training or waiting period. The IBSM group reported lower subjective stress levels after the program than the control group. In addition, the IBSM group exhibited improved coping skills and better sleep quality. Emotional exhaustion was reduced in both groups, while depressive symptoms did not change. These results suggest that a brief, 6-week, cognitive-behavioral internet-based stress management program improves coping skills, sleep quality, and well-being, and reduces the perceived stress of employees. Our results might encourage large-scale studies on the long-term stability and clinical efficacy of internet-based programs. The trial is registered in the German Clinical Trials Register (DRKS00014837) URL. https://www.drks.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00014837.

Oxytocin modulates the temporal dynamics of resting EEG networks

Oxytocin is a key modulator of social interaction, but we possess little knowledge of its underlying effects on neuropsychological processes. We used a spatio-temporal EEG microstates analysis to reveal oxytocin's effects on the temporal dynamics of intrinsically generated activity in neural networks. Given oxytocin's known anxiolytic effects, we hypothesized that it increases the temporal stability of the four archetypal EEG resting networks. Eighty-six male participants had received oxytocin or placebo intranasally before we recorded their resting EEG. As hypothesized, oxytocin globally increased the average duration of the four archetypal resting networks and specifically decreased the occurrence and coverage of an autonomic processing-related network to benefit greater coverage of an attention-related network. Moreover, these neurophysiological changes were more pronounced in participants with high anxiety levels and strong subjectively experienced effects of the oxytocin administration. In sum, our study shows that oxytocin reduces rapid switching among neural resting networks by increasing their temporal stability. Specifically, it seems to reduce the brain's need for preparing the internally-oriented processing of autonomic information, thus enabling the externally-oriented processing of social information. Changes in the temporal dynamics of resting networks might underlie oxytocin's anxiolytic effects - potentially informing innovative psychobiological treatment strategies.

Oxytocin Modulates the Cognitive Appraisal of the Own and Others Close Intimate Relationships

Close and intimate relationships are important promoters of health. Oxytocin and its association with social cognition have been investigated in a large number of studies, especially highlighting the neuropeptide's involvement in attachment behavior and intimate relationships. However, mixed findings on exogenous oxytocin application have led to the focus on moderators and mediators, suggesting that the effects are depended on specific factors - namely context and salience. The objective of the current study was to assess the effect of intranasal oxytocin on social appraisal of own and others' close intimate relationship characteristics. Different characteristics of relationships, including trust or closeness, between romantic couples (unknown and own) were assessed using the Couple Appraisal Task. In a randomized controlled double-blind cross-over within subject design, N = 71 healthy men and women were investigated after receiving first intranasal oxytocin and 2 weeks later placebo, or vice versa. We found an oxytocin-induced increase in the positive appraisal of one's own overall relationship characteristics but not in the evaluation of the relationship of others. The present study - one of the first of its kind administrating oxytocin in a repeated measures cross-over design - adds further evidence to the mediating role of oxytocin in social cognition, specifically with regard to romantic relationship characteristics.

Dyadic Coping and Its Underlying Neuroendocrine Mechanisms - Implications for Stress Regulation

Previous research suggests that neuroendocrine mechanisms underlie inter-individual stress coping in couples. The neuropeptide oxytocin (OT), while regulating stress-sensitive HPA-axis activity might be crucial in this process. The purpose of this study was to examine the impact of dyadic coping abilities and OT on HPA-axis outcomes and constructive behavior during couple conflict. We conducted a secondary analysis of our previous database (Ditzen et al., 2009), assessing the modulating role of dyadic coping and intranasal OT on couple conflict behavior. The data revealed a significant interaction effect of the dyadic coping by oneself score and OT on cortisol responses during couple conflict, suggesting that particularly individuals with low a priori dyadic coping benefit from OT in terms of dampened HPA-activity. The results are in line with previous research suggesting OT’s central role for stress regulation and prosocial behavior. Furthermore, an interaction with dyadic coping indicates adaptations in the sensitivity of the OT system during the individual attachment and relationship history. These data add to the evidence that the neuroendocrine attachment systems influence couple behavior. Future studies of neurobiological mechanisms underlying dyadic coping will be of high relevance for the development of prevention and intervention programs.

Effects of acute stress on social behavior in women

Acute stress is known to increase prosocial behavior in men via a "tend-and-befriend" pattern originally proposed as a specifically female stress response alongside the fight-or-flight response. However, the direct effects of acute stress on women's social behavior have not been investigated. Applying the Trier Social Stress Test for groups (TSST-G), 94 women were confronted with either a stress or control condition. We repeatedly measured their subjective stress responses, salivary cortisol, and heart rate, and investigated their level of trust, trustworthiness, sharing, punishment and non-social risk using social decision paradigms. We detected significant increases in all stress parameters, as well as the wish for closeness during the stress condition. Acute stress exposure elevated prosocial trustworthiness and sharing without affecting non-social risk behavior. These results are in line with findings on the effects of stress in men, and further validate the tend-and-befriend pattern as one possible behavioral response during stress in humans.

Stress-induced body dissatisfaction in women with binge eating disorder

Stress is known to be a trigger for binge eating in individuals with binge eating disorder (BED). However, the influence of stressful situations on BED patients' body image is less understood. Our study objective was to gain insight into the effects of inducing psychosocial stress on body dissatisfaction in women with BED. Overweight women with BED (n = 29) and without an eating disorder (control group, CG; n = 38) underwent the Trier Social Stress Test for Groups (TSST-G stress) and a nonstressful control task (TSST-G no stress). Additionally, to test for the influence of body salience, participants were either exposed or not exposed to a mirror. Participants repeatedly rated their current body dissatisfaction and psychological distress. Simultaneously, biological stress reactivity was measured using salivary cortisol and alpha-amylase (sAA). Participants responded to TSST-G stress with significantly higher psychological and biological stress compared to the TSST-G control task. The psychological distress response was significantly greater in women with BED than the CG. As hypothesized, exposure to acute socioevaluative stress led to exacerbated body dissatisfaction in the BED group only. The findings of the present study suggest that acute socioevaluative stress may play an influential role in BED patients' body dissatisfaction. Body image programs might benefit from targeting stress management or coping skills in patients with BED. (PsycINFO Database Record

Acute social and physical stress interact to influence social behavior: The role of social anxiety

Stress is proven to have detrimental effects on physical and mental health. Due to different tasks and study designs, the direct consequences of acute stress have been found to be wide-reaching: while some studies report prosocial effects, others report increases in antisocial behavior, still others report no effect. To control for specific effects of different stressors and to consider the role of social anxiety in stress-related social behavior, we investigated the effects of social versus physical stress on behavior in male participants possessing different levels of social anxiety. In a randomized, controlled two by two design we investigated the impact of social and physical stress on behavior in healthy young men. We found significant influences on various subjective increases in stress by physical and social stress, but no interaction effect. Cortisol was significantly increased by physical stress, and the heart rate was modulated by physical and social stress as well as their combination. Social anxiety modulated the subjective stress response but not the cortisol or heart rate response. With respect to behavior, our results show that social and physical stress interacted to modulate trust, trustworthiness, and sharing. While social stress and physical stress alone reduced prosocial behavior, a combination of the two stressor modalities could restore prosociality. Social stress alone reduced nonsocial risk behavior regardless of physical stress. Social anxiety was associated with higher subjective stress responses and higher levels of trust. As a consequence, future studies will need to investigate further various stressors and clarify their effects on social behavior in health and social anxiety disorders.

Glucocorticoid administration restores salience network activity in patients with spider phobia

BACKGROUND

Glucocorticoids reduce phobic fear in patients with anxiety disorders. Although the neurobiology of anxiety disorders is not fully understood, convergent structural and functional neuroimaging studies have identified abnormalities in various brain regions, including those in the salience network (SN) and default mode network (DMN). Here, we examine the effects of glucocorticoid administration on SN and DMN activity during the processing of phobic stimuli.

METHODS

We use functional magnetic resonance imaging to record brain activity in 24 female patients with spider phobia who were administered either 20 mg of cortisol or placebo while viewing pictures of spiders. Fourteen healthy female participants were tested with the same task but without substance administration. Independent component analysis (ICA) performed during stimulus encoding identified the SN and DMN as exhibiting synchronized activation in diverse brain regions; thus, we examined the effects of cortisol on these networks. Furthermore, participants had to rate their level of fear at various time points.

RESULTS

Glucocorticoids reduced phobic fear in patients with spider phobia. The ICA performed during stimulus encoding revealed that activity in the SN and DMN was reduced in placebo-treated patients versus healthy controls. Brain activity in the SN, but not the DMN, was altered in cortisol- versus placebo-treated patients to a level that was similar to that observed in healthy controls.

CONCLUSIONS

Activity in both the SN and DMN was reduced in patients with spider phobia. Cortisol administration altered the SN activity to a level that was comparable to that found in healthy controls. This alteration in SN activity might reflect the fear-reducing effects of glucocorticoids in phobia.

Oxytocin and brain activity in humans: A systematic review and coordinate-based meta-analysis of functional MRI studies

Oxytocin (OXT) is a neuropeptide which has a critical role in human social behaviour and cognition. Research investigating the role of OXT on functional brain changes in humans has often used task paradigms that probe socioemotional processes. Preliminary evidence suggests a central role of the amygdala in the social cognitive effects of intranasal OXT (IN-OXT), however, inconsistencies in task-design and analysis methods have led to inconclusive findings regarding a cohesive model of the neural mechanisms underlying OXT's actions. The aim of this meta-analysis was to systematically investigate these findings. A systematic search of PubMed, PsycINFO, and Scopus databases was conducted for fMRI studies which compared IN-OXT to placebo in humans. First, we systematically reviewed functional magnetic resonance imaging (fMRI) studies of IN-OXT, including studies of healthy humans, those with clinical disorders, and studies examining resting-state fMRI (rsfMRI). Second, we employed a coordinate-based meta-analysis for task-based neuroimaging literature using activation likelihood estimation (ALE), whereby, coordinates were extracted from clusters with significant differences in IN-OXT versus placebo in healthy adults. Data were included for 39 fMRI studies that reported a total of 374 distinct foci. The meta-analysis identified task-related IN-OXT increases in activity within a cluster of the left superior temporal gyrus during tasks of emotion processing. These findings are important as they implicate regions beyond the amygdala in the neural effects of IN-OXT. The outcomes from this meta-analysis can guide a priori predictions for future OXT research, and provide an avenue for targeted treatment interventions.

Positive and negative hysteresis effects for the perception of geometric and emotional ambiguities

AIM

The present study utilizes perceptual hysteresis effects to compare the ambiguity of Mona Lisa's emotional face expression (high-level ambiguity) and of geometric cube stimuli (low-level ambiguity).

METHODS

In two experiments we presented series of nine Mona Lisa variants and nine cube variants. Stimulus ambiguity was manipulated by changing Mona Lisa's mouth curvature (Exp. 1) and the cubes' back-layer luminance (Exp. 2). Each experiment consisted of three conditions, two with opposite stimulus presentation sequences with increasing and decreasing degrees of ambiguity, respectively, and a third condition with a random presentation sequence. Participants indicated happy or sad face percepts (Exp. 1) and alternative 3D cube percepts (Exp. 2) by key presses. We studied the influences of a priori perceptual biases (long-term memory) and presentation order (short-term memory) on perception.

RESULTS

Perception followed sigmoidal functions of the stimulus ambiguity morphing parameters. The morphing parameter for the functions' inflection points depended strongly on stimulus presentation order with similar effect sizes but different signs for the two stimulus types (positive hysteresis / priming for the cubes; negative hysteresis / adaptation for Mona Lisa). In the random conditions, the inflection points were located in the middle between those from the two directional conditions for the Mona Lisa stimuli. For the cube stimuli, they were superimposed on one sigmoidal function for the ordered condition.

DISCUSSION

The hysteresis effects reflect the influence of short-term memory during the perceptual disambiguation of ambiguous sensory information. The effects for the two stimulus types are of similar size, explaining up to 34% of the perceptual variance introduced by the paradigm. We explain the qualitative difference between positive and negative hysteresis with adaptation for Mona Lisa and with priming for the cubes. In addition, the hysteresis paradigm allows a quantitative determination of the impact of adaptation and priming during the resolution of perceptual ambiguities. The asymmetric shifts of inflection points in the case of the cube stimuli is likely due to an a priori perceptual bias, reflecting an influence of long-term memory. Whether corresponding influences also exist for the Mona Lisa variants is so far unclear.

Increased neural responses to empathy for pain might explain how acute stress increases prosociality

Recent behavioral investigations suggest that acute stress can increase prosocial behavior. Here, we investigated whether increased empathy represents a potential mechanism for this finding. Using functional magnetic resonance imaging, we assessed the effects of acute stress on neural responses related to automatic and regulatory components of empathy for pain as well as subsequent prosocial behavior. Stress increased activation in brain areas associated with the automatic sharing of others' pain, such as the anterior insula, the anterior midcingulate cortex, and the primary somatosensory cortex. In addition, we found increased prosocial behavior under stress. Furthermore, activation in the anterior midcingulate cortex mediated the effects of stress on prosocial behavior. However, stressed participants also displayed stronger and inappropriate other-related responses in situations which required them to take the perspective of another person, and to regulate their automatic affective responses. Thus, while acute stress may increase prosocial behavior by intensifying the sharing of others' emotions, this comes at the cost of reduced cognitive appraisal abilities. Depending on the contextual constraints, stress may therefore affect empathy in ways that are either beneficial or detrimental.

Testosterone and androgen receptor gene polymorphism are associated with confidence and competitiveness in men

A contribution to a special issue on Hormones and Human Competition. Studies in non-human animals and humans have demonstrated the important role of testosterone in competitive interactions. Here, we investigated whether endogenous testosterone levels predict the decision to compete, in a design excluding spite as a motive underlying competitiveness. In a laboratory experiment with real monetary incentives, 181 men solved arithmetic problems, first under a noncompetitive piece rate, followed by a competition incentive scheme. We also assessed several parameters relevant to competition, such as risk taking, performance, and confidence in one's own performance. Salivary testosterone levels were measured before and 20min after the competition task using mass spectrometry. Participants were also genotyped for the CAG repeat polymorphism of the androgen receptor gene, known to influence the efficacy of testosterone signaling in a reciprocal relationship to the number of CAG repeats. We observed a significant positive association between basal testosterone levels and the decision to compete, and that higher testosterone levels were related to greater confidence in one's own performance. Whereas the number of CAG repeats was not associated with the choice to compete, a lower number of CAG repeats was related to greater confidence in those who chose to compete, but this effect was attributable to the polymorphism's effect on actual performance. An increase in testosterone levels was observed following the experiment, and this increase varied with self-reported high-school math grades. We expand upon the latest research by documenting effects of the androgen system in confidence in one's own ability, and conclude that testosterone promotes competitiveness without spite.

Mona Lisa is always happy - and only sometimes sad

The worldwide fascination of da Vinci's Mona Lisa has been dedicated to the emotional ambiguity of her face expression. In the present study we manipulated Mona Lisa's mouth curvature as one potential source of ambiguity and studied how a range of happier and sadder face variants influences perception. In two experimental conditions we presented different stimulus ranges with different step sizes between stimuli along the happy-sad axis of emotional face expressions. Stimuli were presented in random order and participants indicated the perceived emotional face expression (first task) and the confidence of their response (second task). The probability of responding 'happy' to the original Mona Lisa was close to 100%. Furthermore, in both conditions the perceived happiness of Mona Lisa variants described sigmoidal functions of the mouth curvature. Participants' confidence was weakest around the sigmoidal inflection points. Remarkably, the sigmoidal functions, as well as confidence values and reaction times, differed significantly between experimental conditions. Finally, participants responded generally faster to happy than to sad faces. Overall, the original Mona Lisa seems to be less ambiguous than expected. However, perception of and reaction to the emotional face content is relative and strongly depends on the used stimulus range.

Altered Stress-Induced Regulation of Genes in Monocytes in Adults with a History of Childhood Adversity

Exposure to serious or traumatic events early in life can lead to persistent alterations in physiological stress response systems, including enhanced cross talk between the neuroendocrine and immune system. These programming effects may be mechanistically involved in mediating the effects of adverse childhood experience on disease risk in adulthood. We investigated hormonal and genome-wide mRNA expression responses in monocytes to acute stress exposure, in a sample of healthy adults (n=30) with a history of early childhood adversity, and a control group (n=30) without trauma experience. The early adversity group showed altered hypothalamus-pituitary-adrenal axis responses to stress, evidenced by lower ACTH and cortisol responses. Analyses of gene expression patterns showed that stress-responsive transcripts were enriched for genes involved in cytokine activity, cytokine-cytokine receptor interaction, chemokine activity, and G-protein coupled receptor binding. Differences between groups in stress-induced regulation of gene transcription were observed for genes involved in steroid binding, hormone activity, and G-protein coupled receptor binding. Transcription factor binding motif analysis showed an increased activity of pro-inflammatory upstream signaling in the early adversity group. We also identified transcripts that were differentially correlated with stress-induced cortisol increases between the groups, enriched for genes involved in cytokine-cytokine receptor interaction and glutamate receptor signaling. We suggest that childhood adversity leads to persistent alterations in transcriptional control of stress-responsive pathways, which-when chronically or repeatedly activated-might predispose individuals to stress-related psychopathology.

Disadvantage of Social Sensitivity: Interaction of Oxytocin Receptor Genotype and Child Maltreatment on Brain Structure

BACKGROUND

Oxytocin has received much attention as a prosocial and anxiolytic neuropeptide. In human studies, the G-allele of a common variant (rs53576) in the oxytocin receptor gene (OXTR) has been associated with protective properties such as reduced stress response and higher receptiveness for social support. In contrast, recent studies suggest a detrimental role of the rs53576 G-allele in the context of childhood maltreatment. To further elucidate the role of OXTR, gene by maltreatment interactions on brain structure and function were investigated.

METHODS

Three hundred nine healthy participants genotyped for OXTR rs53576 underwent structural as well as functional magnetic resonance imaging during a common emotional face-matching task. Childhood maltreatment was assessed with the Childhood Trauma Questionnaire (CTQ). Gray matter volumes were investigated by means of voxel-based morphometry across the entire brain.

RESULTS

Structural magnetic resonance imaging data revealed a strong interaction of rs53576 genotype and CTQ scores, mapping specifically to the bilateral ventral striatum. GG homozygotes but not A-allele carriers showed strong gray matter reduction with increasing CTQ scores. In turn, lower ventral striatum gray matter volumes were associated with lower reward dependence, a prosocial trait. Furthermore, the G-allele was associated with increased amygdala responsiveness to emotional facial expressions.

CONCLUSIONS

The findings suggest that the G-allele constitutes a vulnerability factor for specific alterations of limbic brain structure in individuals with adverse childhood experiences, complemented by increased limbic responsiveness to emotional interpersonal stimuli. While oxytocinergic signaling facilitates attachment and bonding in supportive social environments, this attunement for social cues may turn disadvantageous under early adverse conditions.

Oxytocin's inhibitory effect on food intake is stronger in obese than normal-weight men

Background/Objectives:

Animal studies and pilot experiments in men indicate that the hypothalamic neuropeptide oxytocin limits food intake, and raise the question of its potential to improve metabolic control in obesity.

Subjects/Methods:

We compared the effect of central nervous oxytocin administration (24 IU) via the intranasal route on ingestive behaviour and metabolic function in 18 young obese men with the results in a group of 20 normal-weight men. In double-blind, placebo-controlled experiments, ad libitum food intake from a test buffet was examined in fasted subjects 45 min after oxytocin administration, followed by the assessment of postprandial, reward-driven snack intake. Energy expenditure was repeatedly assessed by indirect calorimetry and blood was sampled to determine concentrations of blood glucose and hormones.

Results:

Oxytocin markedly reduced hunger-driven food intake in the fasted state in obese but not in normal-weight men, and led to a reduction in snack consumption in both groups, whereas energy expenditure remained generally unaffected. Hypothalamic–pituitary–adrenal axis secretion and the postprandial rise in plasma glucose were blunted by oxytocin in both groups.

Conclusions:

Oxytocin exerts an acutely inhibitory impact on food intake that is enhanced rather than decreased in obese compared with normal-weight men. This pattern puts it in contrast to other metabolically active neuropeptides and bodes well for clinical applications of oxytocin in the treatment of metabolic disorders.

As time goes by: Oxytocin influences the subjective perception of time in a social context

Time perception depends on an event's emotional relevance to the beholder; a subjective time dilation effect is associated with self-relevant, emotionally salient stimuli. Previous studies have revealed that oxytocin modulates the salience of social stimuli and attention to social cues. However, whether the oxytocin system is involved in human subjective time perception is unknown. The aim of the present study was to investigate whether increased oxytocin levels would induce a time dilation effect for self-relevant, positive social cues. In a double-blind, placebo-controlled, between-subject design, heterosexual men were administered intranasal oxytocin or placebo. After about 50min, participants completed a time-bisection task in which they estimated lengths of exposure to happy female faces (self-relevant positive stimuli, based on sexual orientation), emotionally neutral and negative female faces (control), and happy, neutral, and negative male faces (control). Oxytocin induced a subjective time dilation effect for happy female faces and a time compression effect for happy male faces. Our results provide evidence that oxytocin influences time perception, a primary form of human subjectivity.