A general approach-avoidance hypothesis of oxytocin: accounting for social and non-social effects of oxytocin

Oxytocin reduces top-down control of attention by increasing bottom-up attention allocation to social but not non-social stimuli - A randomized controlled trial

The neuropeptide oxytocin (OXT) may facilitate attention to social stimuli by influencing early stage bottom-up processing although findings in relation to different emotional expressions are inconsistent and its influence on top-down cognitive processing mechanisms unclear. In the current double-blind placebo (PLC) controlled between-subject design study we therefore recruited 71 male subjects (OXT = 34, PLC = 37) to investigate the effects of intranasal OXT (24IU) on both bottom-up attention allocation and top-down attention inhibition using a prosaccade and antisaccade paradigm incorporating social (neutral, happy, fearful, sad, angry faces) and non-social (oval shape) visual stimuli with concurrent eye movement acquisition. Results revealed a marginal significant interaction effect between treatment, condition and task (p = 0.054), with Bonferroni-corrected post-hoc tests indicating that OXT specifically increased antisaccade errors for social stimuli (ps < 0.04, effect sizes 0.46-0.88), but not non-social stimuli. Antisaccades are under volitional control and therefore this may indicate that OXT treatment reduced top-down inhibition. However, the overall findings are consistent with OXT acting to reduce top-down control of attention as a result of increasing bottom-up early attentional processing of social, but not non-social, stimuli in situations where the two systems are in potential conflict. Marked deficits in bottom-up attention allocation to social stimuli have been reported in autism spectrum disorder, within this context OXT may have the potential to increase early attention allocation towards social cues.

Oxytocin reduces interpersonal distance: Examining moderating effects of childrearing experiences and interpersonal context in virtual reality

Oxytocin has been shown to stimulate social approach behaviors, although effects may depend on contextual and individual difference factors. Here, we examined intranasal oxytocin effects on interpersonal distance using an immersive Virtual Reality paradigm, taking into account early caregiving experiences and interpersonal context as potential moderators. Participants were 180 women who received 24 IU oxytocin or a placebo and had reported how often their mother used love withdrawal as a disciplinary strategy, involving withholding love and affection after a failure or misbehavior. We used a virtual stop-distance paradigm, instructing participants to approach a virtual person or to stop an approaching virtual person at a preferred distance (passive approach). In order to examine the role of interpersonal context in shaping oxytocin effects, facial expressions and bodily gestures of the virtual person were manipulated. The person showed a dynamical expression of sadness, happiness, anger, fear, disgust, or no emotional expression in six different emotion conditions. We found that oxytocin reduced interpersonal distance across the different emotion conditions, but only in individuals with lower levels of love withdrawal. In addition, oxytocin reduced anxiety levels during passive approach, in particular in the disgust condition, but only in individuals with lower levels of maternal disciplinary love withdrawal. Individuals with more love withdrawal experienced more anxiety while being approached by a virtual person displaying disgust or fear, but benefitted less from anxiety-reducing oxytocin effects. These results are consistent with previous research showing a dysregulated oxytocinergic system after childhood adversity and indicate that oxytocin may be less effective for individuals who are most in need of an intervention because of a problematic family background.

Impaired approach to novelty and striatal alterations in the oxytocin receptor deficient mouse model of autism

Long-standing studies established a role for the oxytocin system in social behavior, social reward, pair bonding and affiliation. Oxytocin receptors, implicated in pathological conditions affecting the social sphere such as autism spectrum disorders, can also modulate cognitive processes, an aspect generally overlooked. Here we examined the effect of acute (pharmacological) or genetic (Oxtr^-/-) inactivation of oxytocin receptor-mediated signaling, in male mice, in several cognitive tests. In the novel object recognition test, both oxytocin receptor antagonist treated wild type animals and Oxtr^-/- mice lacked the typical preference for novelty. Oxtr^-/- mice even preferred the familiar object; moreover, their performance in the Morris water maze did not differ from wild types, suggesting that oxytocin receptor inactivation did not disrupt learning. Because the preference for novel objects could be rescued in Oxtr^-/- mice with longer habituation periods, we propose that the loss of novelty preferences following Oxtr inactivation is due to altered processing of novel contextual information. Finally, we observed an increased expression of excitatory synaptic markers in the striatum of Oxtr^-/- mice and a greater arborization and higher number of spines/neuron in the dorsolateral area of this structure, which drives habit formation. Our data also indicate a specific reshaping of dorsolateral striatal spines in Oxtr^-/- mice after exposure to a novel environment, which might subtend their altered approach to novelty, and support previous work pointing at this structure as an important substrate for autistic behaviors.

The effect of oxytocin administration on empathy and emotion recognition in residential youth: A randomized, within-subjects trial

Previous research has revealed a positive effect of oxytocin administration on several social behaviors especially in individuals with social-affective deficits. However, it is still unknown whether intranasal oxytocin administration (OT-IN) can be beneficial to residential youth who exhibit severe social-affective impairments. We conducted a randomized, double-blind, placebo-controlled, within-subjects, sequential study to examine the effect of OT-IN on empathy and emotion recognition in 100 male adolescents living in residential youth care facilities. We also explored the moderating role of callous-unemotional traits, trauma, and dissociation in the oxytocin effect. Participants self-administered one dose of 24 IU of oxytocin or placebo and performed experimental tasks on empathy and emotion recognition before and after the administration. The same procedure was performed one week later with the other substance. We found that empathy was increased after oxytocin administration compared to placebo and this effect was specific to individuals with high callous-unemotional traits. There was no effect of OT-IN on the overall emotion recognition, but there was a positive effect on accuracy of fear recognition. Trauma and dissociation did not moderate the oxytocin effect on empathy or emotion recognition. Our findings provided evidence of a beneficial effect of OT-IN on empathy and fear recognition in residential youth. We propose that a combination of OT-IN and psychological interventions merits further exploration, as it might be a novel promising direction for more tailored approaches and better treatment outcomes.

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.

Subjective and Oxytocinergic Responses to Mindfulness Are Associated With Subjective and Oxytocinergic Responses to Sexual Arousal

Mindfulness – the ability to pay attention, on purpose, without judgment, and in the present moment – has consistently been shown to enhance women’s sexual arousal. As a first step toward understanding potential neuroendocrine underpinnings of mindfulness and sexual arousal, we examined whether individual differences in subjective and neuroendocrine (i.e., oxytocin) responses to mindful breathing were associated with individual differences in subjective and neuroendocrine responses to sexual arousal. To achieve this aim, 61 lesbian, bisexual, and heterosexual women completed a questionnaire assessing dispositional mindfulness, underwent an arousal task while continuously rating their sexual arousal and a mindful breathing task, after which participants reported on their ability to detect attentional shifts, and provided salivary samples after each assessment. Results indicated that women who were quicker to detect attentional shifts and women who reported greater sexual arousability reported larger changes (decreases) in oxytocin in response to mindful breathing and were the only women to report increases in oxytocin in response to the sexual arousal induction. Results further indicated that individuals who report greater subjective responsiveness to mindfulness and sexual arousal appear to have an oxytocinergic system that is also more responsive to both arousal and to mindfulness. These results make a significant contribution to our understanding of the role of attentional processes in sexual arousal, and warrant future examination of oxytocin as a potential neuroendocrine mechanism underlying the link between mindfulness and sexual arousal.

Oxytocin Enhances the Neural Efficiency of Social Perception

Face perception is a highly conserved process that directs our attention from infancy and is supported by specialized neural circuitry. Oxytocin (OT) can increase accuracy and detection of emotional faces, but these effects are mediated by valence, individual differences, and context. We investigated the temporal dynamics of OT’s influence on the neural substrates of face perception using event related potentials (ERPs). In a double blind, placebo controlled within-subject design, 21 healthy male adults inhaled OT or placebo and underwent ERP imaging during two face processing tasks. Experiment 1 investigated effects of OT on neural correlates of fearful vs. neutral facial expressions, and Experiment 2 manipulated point-of-gaze to neutral faces. In Experiment 1, we found that OT reduced N170 latency to fearful faces. In Experiment 2, N170 latency was decreased when participant gaze was directed to the eyes of neutral faces; however, there were no OT-associated effects in response to different facial features. Findings suggest OT modulates early stages of social perception for socially complex information such as emotional faces relative to neutral. These results are consistent with models suggesting OT impacts the salience of socially informative cues during processing, which leads to downstream effects in behavior. Future work should examine how OT affects neural processes underlying basic components of social behavior (such as, face perception) while varying emotional expression of stimuli or comparing different characteristics of participants (e.g., gender, personality traits).

Role of oxytocin in the control of stress and food intake

Oxytocin neurones in the hypothalamus are activated by stressful stimuli and food intake. The oxytocin receptor is located in various brain regions, including the sensory information-processing cerebral cortex; the cognitive information-processing prefrontal cortex; reward-related regions such as the ventral tegmental areas, nucleus accumbens and raphe nucleus; stress-related areas such as the amygdala, hippocampus, ventrolateral part of the ventromedial hypothalamus and ventrolateral periaqueductal gray; homeostasis-controlling hypothalamus; and the dorsal motor complex controlling intestinal functions. Oxytocin affects behavioural and neuroendocrine stress responses and terminates food intake by acting on the metabolic or nutritional homeostasis system, modulating emotional processing, reducing reward values of food intake, and facilitating sensory and cognitive processing via multiple brain regions. Oxytocin also plays a role in interactive actions between stress and food intake and contributes to adaptive active coping behaviours.

Expanding Regulation Theory With Oxytocin: A Psychoneurobiological Model for Infant Development

BACKGROUND

Oxytocin (OT), an affiliation hormone released during supportive social interactions, provides an exemplar of how social environments are reflected in our neurobiology from the beginning of life. A growing body of OT research has uncovered previously unknown functions of OT, including modulation of parenting behaviors, neuroprotection, affiliation, and bonding. Regulation theory provides a strong framework for describing how the maternal care environment affects infant neurodevelopment through a symphony of molecules that form the neurobiological milieu of the developing infant brain.

OBJECTIVES

The purpose of this article was to expand on regulation theory by discussing how OT-based processes contribute to infant neurobiology and by proposing a new model for maternal-infant nursing practice and research.

APPROACH

We structure our discussion of the socially based, neurobiological processes of OT through its effects in the nested hierarchies of genetic, epigenetic, molecular, cellular, neural circuit, multiorgan, and behavioral levels. Our discussion is also presented chronologically, as OT works through a positive feedback loop during infant neurodevelopment, beginning prenatally and continuing after birth.

IMPLICATIONS

Nurses are in a unique position to use innovative discoveries made by the biologic sciences to generate new nursing theories that inform clinical practice and inspire the development of innovative interventions that maximize the infant's exposure to supportive maternal care.

Low-dose intranasal oxytocin delivered with Breath Powered device modulates pupil diameter and amygdala activity: a randomized controlled pupillometry and fMRI study

Little is known about how intranasally administered oxytocin reaches the brain and modulates social behavior and cognition. Pupil dilation is a sensitive index of attentional allocation and effort, and inter-individual variability in pupil diameter during performance of social-cognitive tasks may provide a better assessment of pharmacological effects on the brain than behavioral measures. Here, we leverage the close relationship between pupil and neural activity to inform our understanding of nose-to-brain oxytocin routes and possible dose-response relationships. To this end, we assessed pupil diameter data from a previously reported functional magnetic resonance imaging (fMRI) study under four treatment conditions-including two different doses of intranasal oxytocin using a novel Breath Powered nasal device, intravenous (IV) oxytocin, and placebo-and investigated the association with amygdala activation in response to emotional stimuli. The study used a randomized, double-blind, double-dummy, crossover design, with 16 healthy male adults administering a single-dose of these four treatments. A significant main effect of treatment condition on pupil diameter was observed. Posthoc tests revealed reduced pupil diameter after 8IU intranasal oxytocin compared to placebo, but no significant difference between 8IU intranasal oxytocin and either 24IU intranasal oxytocin or IV oxytocin treatment conditions. Analysis also showed a significant relationship between pupil diameter and right amygdala activation after 8IU intranasal oxytocin. Although there was no significant difference between 8IU intranasal oxytocin and IV oxytocin on right amygdala activity and pupil diameter, the significant difference between 8IU intranasal oxytocin and placebo is consistent with the hypothesis that oxytocin can travel to the brain via a nose-to-brain route.

Oxytocin Modulates the Intrinsic Dynamics Between Attention-Related Large-Scale Networks

Attention and salience processing have been linked to the intrinsic between- and within-network dynamics of large-scale networks engaged in internal (default network [DN]) and external attention allocation (dorsal attention network [DAN] and salience network [SN]). The central oxytocin (OXT) system appears ideally organized to modulate widely distributed neural systems and to regulate the switch between internal attention and salient stimuli in the environment. The current randomized placebo (PLC)-controlled between-subject pharmacological resting-state fMRI study in N = 187 (OXT, n = 94; PLC, n = 93; single-dose intranasal administration) healthy male and female participants employed an independent component analysis approach to determine the modulatory effects of OXT on the within- and between-network dynamics of the DAN-SN-DN triple network system. OXT increased the functional integration between subsystems within SN and DN and increased functional segregation of the DN with both attentional control networks (SN and DAN). Whereas no sex differences were observed, OXT effects on the DN-SN interaction were modulated by autistic traits. Together, the findings suggest that OXT may facilitate efficient attention allocation by modulating the intrinsic functional dynamics between DN components and large-scale networks involved in external attentional demands (SN and DAN).

A Longitudinal Multilevel Study of the "Social" Genotype and Diversity of the Phenotype

Sociability and social domain-related behaviors have been associated with better well-being and endogenous oxytocin levels. Inspection of the literature, however, reveals that the effects between sociability and health outcomes, or between sociability and genotype, are often weak or inconsistent. In the field of personality psychology, the social phenotype is often measured by error-prone assessments based on different theoretical frameworks, which can partly explain the inconsistency of the previous findings. In this study, we evaluated the generalizability of “sociability” measures by partitioning the population variance in adulthood sociability using five indicators from three personality inventories and assessed in two to four follow-ups over a 15-year period (n = 1,573 participants, 28,323 person-observations; age range 20–50 years). Furthermore, we tested whether this variance partition would shed more light to the inconsistencies surrounding the “social” genotype, by using four genetic variants (rs1042778, rs2254298, rs53576, rs3796863) previously associated with a wide range of human social functions. Based on our results, trait (between-individual) variance explained 23% of the variance in overall sociability, differences between sociability indicators explained 41%, state (within-individual) variance explained 5% and measurement errors explained 32%. The genotype was associated only with the sociability indicator variance, suggesting it has specific effects on sentimentality and emotional sharing instead of reflecting general sociability.

Diminished positive affect and traumatic stress: A biobehavioral review and commentary on trauma affective neuroscience

Post-traumatic stress manifests in disturbed affect and emotion, including exaggerated severity and frequency of negative valence emotions, e.g., fear, anxiety, anger, shame, and guilt. However, another core feature of common post-trauma psychopathologies, i.e. post-traumatic stress disorder (PTSD) and major depression, is diminished positive affect, or reduced frequency and intensity of positive emotions and affective states such as happiness, joy, love, interest, and desire/capacity for interpersonal affiliation. There remains a stark imbalance in the degree to which the neuroscience of each affective domain has been probed and characterized in PTSD, with our knowledge of post-trauma diminished positive affect remaining comparatively underdeveloped. This remains a prominent barrier to realizing the clinical breakthroughs likely to be afforded by the increasing availability of neuroscience assessment and intervention tools. In this review and commentary, the author summarizes the modest extant neuroimaging literature that has probed diminished positive affect in PTSD using reward processing behavioral paradigms, first briefly reviewing and outlining the neurocircuitry implicated in reward and positive emotion and its interrelationship with negative emotion and negative valence circuitry. Specific research guidelines are then offered to best and most efficiently develop the knowledge base in this area in a way that is clinically translatable and will exert a positive impact on routine clinical care. The author concludes with the prediction that the development of an integrated, bivalent theoretical and predictive model of how trauma impacts affective neurocircuitry to promote post-trauma psychopathology will ultimately lead to breakthroughs in how trauma treatments are conceptualized mechanistically and developed pragmatically.

Oxytocin differentially modulates specific dorsal and ventral striatal functional connections with frontal and cerebellar regions

Interactions between oxytocin and the basal ganglia are central in current overarching conceptualizations of its broad modulatory effects on behavior. Whereas evidence from animal models emphasizes the critical role of the ventral striatum in the behavioral effects of oxytocin, region-specific contributions of the basal ganglia have not been systematically explored in humans. The present study combined the randomized placebo-controlled administration of oxytocin versus placebo in healthy men (n = 144) with fMRI-based resting-state functional connectivity to determine the modulatory role of oxytocin on the major basal ganglia pathways. Oxytocin specifically increased connectivity between ventral striatal and pallidal nodes with upstream frontal regions, whereas it decreased the strengths of downstream pathways between the dorsal striatum and posterior cerebellum. These pathways have previously been implicated in salience, reward and behavioral flexibility, thus shaping goal-directed behavior. Given the importance of aberrant striatal intrinsic organization in autism, addiction and schizophrenia the present findings may suggest new mechanistic perspectives for the therapeutic potential of oxytocin in these disorders.

Oxytocin Facilitates Approach Behavior to Positive Social Stimuli via Decreasing Anterior Insula Activity

BACKGROUND

The neuropeptide oxytocin can extensively modulate human social behavior and affective processing, and its effects can be interpreted in terms of mediating approach-avoidance motivational processes. However, little is known about how oxytocin mediates approach-avoidance behavior and particularly the underlying neural mechanisms.

METHODS

In a randomized, double-blind, between-subject design, the present pharmaco-fMRI study used an approach-avoidance paradigm to investigate oxytocin's effects on approach-avoidance behavior and associated neural mechanisms.

RESULTS

Results revealed that oxytocin generally decreased activity in the right striatum irrespective of response (approach/avoidance) and social context, suggesting an inhibitory effect on motivational representation during both appetitive approach and aversive avoidance. Importantly, while on the behavioral level oxytocin selectively enhanced accuracy when approaching social positive stimuli, on the neural level it decreased left ventral and right dorsal anterior insula activity in response to social vs nonsocial positive stimuli compared with the placebo treatment. The left ventral anterior insula activity was negatively correlated with the corresponding accuracy difference scores in the oxytocin but not in the placebo group.

CONCLUSION

Given the role of the ventral anterior insula in emotional processing and the dorsal anterior insula in salience processing, the oxytocin-induced suppression of activity in these regions may indicate that oxytocin is acting to reduce interference from hyper-activity in core regions of the emotional and salience networks when approaching salient positive social stimuli and thereby to promote social interaction. Thus, oxytocin may be of potential therapeutic benefit for psychiatric disorders exhibiting avoidance of social stimuli.

An integrated framework for the role of oxytocin in multistage social decision-making

Interest in the effects of oxytocin on social behavior has persisted even as an overarching theory describing these effects has remained largely elusive. Some of the earliest studies on the effects of oxytocin on social decision-making indicated that oxytocin might enhance prosocial actions directed toward others. This led to development of the prosocial hypothesis, which stipulates that oxytocin specifically enhances prosocial choices. However, further work indicated that oxytocin administration could elicit antisocial behaviors as well in certain social situations, highlighting the importance of context-dependent effects. At least two prominent hypotheses have been used to explain these seemingly contradictory findings. The social salience hypothesis indicates that the effects of oxytocin can be conceptualized as a general increase in the salience of social stimuli in the environment. Distinctly, the approach/withdrawal hypothesis stipulates that oxytocin enhances approach behaviors and decreases withdrawal behaviors. These phenomenologically motivated hypotheses regarding the effects of oxytocin on social behavior have created controversies in the field. In this review, we present a multistage framework of social decision-making designed to unify these disparate theories in a process common to all social decisions. We conceptualize this process as involving multiple distinct computational steps, including sensory input, sensory perception, valuation, decision formulation, and behavioral output. Iteratively, these steps generate social behaviors, and oxytocin could be acting on any of these steps to exert its effects. In support of this framework, we examine both behavioral and neural evidence across rodents, non-human primates, and humans, determining at what point in our multistage framework oxytocin could be eliciting its socially relevant effects. Finally, we postulate based on our framework that the prosocial, social salience, and approach/withdrawal hypotheses may not be mutually exclusive and could explain the influence of oxytocin on social behavior to different extents depending on context.

Intranasal oxytocin increases neural responses to social reward in post-traumatic stress disorder

Therapeutic alliance and perceived social support are important predictors of treatment response for post-traumatic stress disorder (PTSD). Intranasal oxytocin administration may enhance treatment response by increasing sensitivity for social reward and thereby therapeutic alliance and perceived social support. As a first step to investigate this therapeutical potential, we investigated whether intranasal oxytocin enhances neural sensitivity to social reward in PTSD patients. Male and female police officers with (n = 35) and without PTSD (n = 37) were included in a double-blind, randomized, placebo-controlled cross-over fMRI study. After intranasal oxytocin (40 IU) and placebo administration, a social incentive delay task was conducted to investigate neural responses during social reward and punishment anticipation and feedback. Under placebo, PTSD patients showed reduced left anterior insula (AI) responses to social rewards (i.e. happy faces) compared with controls. Oxytocin administration increased left AI responses during social reward in PTSD patients, such that PTSD patients no longer differed from controls under placebo. Furthermore, in PTSD patients, oxytocin increased responses to social reward in the right putamen. By normalizing abberant insula responses and increasing putamen responses to social reward, oxytocin administration may enhance sensitivity for social support and therapeutic alliance in PTSD patients. Future studies are needed to investigate clinical effects of oxytocin.

Oxytocin conditions trait-based rule adherence

Rules, whether in the form of norms, taboos or laws, regulate and coordinate human life. Some rules, however, are arbitrary and adhering to them can be personally costly. Rigidly sticking to such rules can be considered maladaptive. Here, we test whether, at the neurobiological level, (mal)adaptive rule adherence is reduced by oxytocin—a hypothalamic neuropeptide that biases the biobehavioural approach-avoidance system. Participants (N = 139) self-administered oxytocin or placebo intranasally, and reported their need for structure and approach-avoidance sensitivity. Next, participants made binary decisions and were given an arbitrary rule that demanded to forgo financial benefits. Under oxytocin, participants violated the rule more often, especially when they had high need for structure and high approach sensitivity. Possibly, oxytocin dampens the need for a highly structured environment and enables individuals to flexibly trade-off internal desires against external restrictions. Implications for the treatment of clinical disorders marked by maladaptive rule adherence are discussed.

Oxytocin attenuates social and non-social avoidance: Re-thinking the social specificity of Oxytocin

Re-examining decades of the social construal of Oxytocin, the General Approach-Avoidance Hypothesis of Oxytocin (GAAO) predicts that Oxytocin will modulate responding to emotionally-evocative and personally-relevant social and non-social stimuli due to its action on the neural substrate of approach and avoidance motivation. We report the first critical experimental test of GAAO predictions by means of a double-blind intra-nasal administration of Oxytocin vs. placebo in 90 healthy adults (N=90, 50% women). As predicted, we found that among men and women for whom negative emotion (anxious arousal) is motivationally-relevant, intra-nasal administration of Oxytocin reduced behavioral avoidance of emotionally-evocative negatively-valenced social and non-social stimuli, but not closely matched emotionally-neutral stimuli. Findings cannot be explained by extant social theories of Oxytocin. We discuss the implications of the present findings for basic and translational clinical Oxytocin research.

Oxytocin promotes intuitive rather than deliberated cooperation with the in-group

A contribution to a special issue on Hormones and Human Competition. In intergroup settings, individuals prefer cooperating with their in-group, and sometimes derogate and punish out-groups. Here we replicate earlier work showing that such in-group bounded cooperation is conditioned by oxytocin and extend it by showing that oxytocin-motivated in-group cooperation is intuitive rather than deliberated. Healthy males (N=65) and females (N=129) self-administered intranasal placebo or 24IU oxytocin in a double-blind placebo-controlled between-subjects design, were assigned to a three-person in-group (that faced a 3-person out-group), and given an endowment from which they could contribute to a within-group pool (benefitting the in-group), and/or to a between-group pool (benefitting the in-group and punishing the out-group). Prior to decision-making, participants performed a Stroop Interference task that was either cognitively taxing, or not. Cognitively taxed individuals kept less to themselves and contributed more to the within-group pool. Furthermore, participants receiving placebo contributed more to the within-group pool when they were cognitively taxed rather than not; those receiving oxytocin contributed to the within-group pool regardless of cognitive taxation. Neither taxation nor treatment influenced contributions to the between-group pool, and no significant sex differences were observed. It follows that in intergroup settings (i) oxytocin increases in-group bounded cooperation, (ii) oxytocin neither reduces nor increases out-group directed spite, and (iii) oxytocin-induced in-group cooperation is independent of cognitive taxation and, therefore, likely to be intuitive rather than consciously deliberated.

Recognition of facial expressions is moderated by Islamic cues

Recognising emotions from faces that are partly covered is more difficult than from fully visible faces. The focus of the present study is on the role of an Islamic versus non-Islamic context, i.e. Islamic versus non-Islamic headdress in perceiving emotions. We report an experiment that investigates whether briefly presented (40 ms) facial expressions of anger, fear, happiness and sadness are perceived differently when covered by a niqāb or turban, compared to a cap and shawl. In addition, we examined whether oxytocin, a neuropeptide regulating affection, bonding and cooperation between ingroup members and fostering outgroup vigilance and derogation, would differentially impact on emotion recognition from wearers of Islamic versus non-Islamic headdresses. The results first of all show that the recognition of happiness was more accurate when the face was covered by a Western compared to Islamic headdress. Second, participants more often incorrectly assigned sadness to a face covered by an Islamic headdress compared to a cap and shawl. Third, when correctly recognising sadness, they did so faster when the face was covered by an Islamic compared to Western headdress. Fourth, oxytocin did not modulate any of these effects. Implications for theorising about the role of group membership on emotion perception are discussed.

Oxytocin reduces amygdala responses during threat approach

Oxytocin reduces amygdala responses to threatening social stimuli in males and has been suggested to facilitate approach-related processing by either decreasing anxiety or intensifying salience. The current administration study tested whether oxytocin either reduces or enhances amygdala responses during threat approach in a placebo-controlled randomized, double-blind, between-subjects design with 52 healthy males undergoing fMRI during a social approach-avoidance task. Oxytocin decreased amygdala activation during threat approach and not during threat avoidance. This neural effect supports oxytocin's social anxiolytic effects and provides a neuroendocrine mechanism promoting social approach. The findings may yield clinical implications for individuals suffering from dysregulations of social approach such as patients with anxiety disorders.

Oxytocin modulates third-party sanctioning of selfish and generous behavior within and between groups

Human groups function because members trust each other and reciprocate cooperative contributions, and reward others' cooperation and punish their non-cooperation. Here we examined the possibility that such third-party punishment and reward of others' trust and reciprocation is modulated by oxytocin, a neuropeptide generally involved in social bonding and in-group (but not out-group) serving behavior. Healthy males and females (N=100) self-administered a placebo or 24 IU of oxytocin in a randomized, double-blind, between-subjects design. Participants were asked to indicate (incentivized, costly) their level of reward or punishment for in-group (outgroup) investors donating generously or fairly to in-group (outgroup) trustees, who back-transferred generously, fairly or selfishly. Punishment (reward) was higher for selfish (generous) investments and back-transfers when (i) investors were in-group rather than outgroup, and (ii) trustees were in-group rather than outgroup, especially when (iii) participants received oxytocin rather than placebo. It follows, first, that oxytocin leads individuals to ignore out-groups as long as out-group behavior is not relevant to the in-group and, second, that oxytocin contributes to creating and enforcing in-group norms of cooperation and trust.

Oxytocin and Stress-related Disorders: Neurobiological Mechanisms and Treatment Opportunities

Novel pharmacotherapies that improve outcomes for individuals with stress-related psychiatric disorders are needed. The neurohormone oxytocin (OT) is a promising candidate given its influence on the social-emotional brain. In this review, we present an overview of evidence supporting OT's utility for treating major depressive disorder and posttraumatic stress disorder. We first discuss endogenous OT, which research suggests is not yet a reliable biomarker of stress-related disorders. Second, we review effects of intranasal (IN) OT on processes relevant to stress-related disorders in healthy populations (anhedonia, reward processing, psychosocial stress reactivity, fear/anxiety, and social behavior) and their neurobiological mechanisms (e.g., the salience network and hypothalamic-pituitary-adrenal axis). Third, we present the sparse but promising findings from clinical populations, followed by discussion of critical moderating variables to consider in the service of maximizing the therapeutic potential of OT (e.g., patient sex and child maltreatment). We also identify heterogeneous findings and limitations of existing research, including reliance on single-dose studies in psychiatrically healthy samples and unanswered questions regarding the effectiveness of IN drug delivery and dosing schedules. Well-controlled multidose studies including women and measures of potentially moderating variables are sorely needed and would inform our understanding of the utility of OT for preventing and treating stress-related psychiatric disorders.

Does oxytocin lead to emotional interference during a working memory paradigm?

BACKGROUND

Oxytocin administration may increase attention to emotional information. We hypothesized that this augmented emotional processing might in turn lead to interference on concurrent cognitive tasks. To test this hypothesis, we examined whether oxytocin administration would lead to heightened emotional interference during a working memory paradigm. Additionally, moderating effects of childhood maltreatment were explored.

METHODS

Seventy-eight healthy males received 24 IU of intranasal oxytocin or placebo in a randomized placebo-controlled double-blind between-subjects study. A working memory task was performed during which neutral, positive, and negative distractors were presented.

RESULTS

The main outcome observed was that oxytocin did not enhance interference by emotional information during the working memory task. There was a non-significant trend for oxytocin to slow down performance irrespective of distractor valence, while accuracy was unaffected. Exploratory analyses showed that childhood maltreatment was related to lower overall accuracy, but in the placebo condition only. However, the maltreated group sample size was very small precluding any conclusions on its moderating effect.

CONCLUSIONS

Despite oxytocin's previously proposed role in enhanced emotional processing, no proof was found that this would lead to reduced performance on a concurrent cognitive task. The routes by which oxytocin exerts its effects on cognitive and social-emotional processes remain to be fully elucidated.

Assessing Emotional Vocalizations From Cultural In-Group and Out-Group Depends on Oxytocin

Group-living animals, humans included, produce vocalizations like screams, growls, laughs, and victory calls. Accurately decoding such emotional vocalizations serves both individual and group functioning, suggesting that (i) vocalizations from in-group members may be privileged, in terms of speed and accuracy of processing, and (ii) such processing may depend on evolutionary ancient neural circuitries that sustain and enable cooperation with and protection of the in-group against outside threat. Here, we examined this possibility and focused on the neuropeptide oxytocin. Dutch participants self-administered oxytocin or placebo (double-blind, placebo-controlled study design) and responded to emotional vocalizations produced by cultural in-group members (Native Dutch) and cultural out-group members (Namibian Himba). In-group vocalizations were recognized faster and more accurately than out-group vocalizations, and oxytocin enhanced accurate decoding of specific vocalizations from one’s cultural out-group—triumph and anger. We discuss possible explanations and suggest avenues for new research.

Affectionate Touch to Promote Relational, Psychological, and Physical Well-Being in Adulthood: A Theoretical Model and Review of the Research

Throughout the life span, individuals engage in affectionate touch with close others. Touch receipt promotes well-being in infancy, but the impacts of touch in adult close relationships have been largely unexplored. In this article, we propose that affectionate touch receipt promotes relational, psychological, and physical well-being in adulthood, and we present a theoretical mechanistic model to explain why affectionate touch may promote these outcomes. The model includes pathways through which touch could affect well-being by reducing stress and by promoting well-being independent of stress. Specifically, two immediate outcomes of affectionate touch receipt—relational-cognitive changes and neurobiological changes—are described as important mechanisms underlying the effects of affectionate touch on well-being. We also review and evaluate the existing research linking affectionate touch to well-being in adulthood and propose an agenda to advance research in this area. This theoretical perspective provides a foundation for future work on touch in adult close relationships.

Oxytocin, but not vasopressin, impairs social cognitive ability among individuals with higher levels of social anxiety: a randomized controlled trial

Individuals with social anxiety are characterized by a high degree of social sensitivity, which can coincide with impairments in social cognitive functioning (e.g. theory of mind). Oxytocin (OT) and vasopressin (AVP) have been shown to improve social cognition, and OT has been theorized as a potential therapeutic agent for individuals with social anxiety disorder. However, no study has investigated whether these neuropeptides improve social cognitive ability among socially anxious individuals. In a randomized, double-blind, placebo controlled, between-subjects design we investigated whether social anxiety moderated the effects of OT or AVP (vs placebo) on social working memory (i.e. working memory that involves manipulating social information) and non-social working memory. OT vs placebo impaired social working memory accuracy in participants with higher levels of social anxiety. No differences were found for non-social working memory or for AVP vs placebo. Results suggest that OT administration in individuals with higher levels of social anxiety may impair social cognitive functioning. Randomized-controlled trial registration: NCT01680718.

Intranasal oxytocin enhances neural processing of monetary reward and loss in post-traumatic stress disorder and traumatized controls

BACKGROUND

Anhedonia is a significant clinical problem in post-traumatic stress disorder (PTSD). PTSD patients show reduced motivational approach behavior, which may underlie anhedonic symptoms. Oxytocin administration is known to increase reward sensitivity and approach behavior. We therefore investigated whether oxytocin administration affected neural responses during motivational processing in PTSD patients and trauma-exposed controls.

METHODS

35 police officers with PTSD (21 males) and 37 trauma-exposed police officers without PTSD (19 males) were included in a within-subjects, randomized, placebo-controlled fMRI study. Neural responses during anticipation of monetary reward and loss were investigated with a monetary incentive delay task (MID) after placebo and oxytocin (40 IU) administration.

RESULTS

Oxytocin increased neural responses during reward and loss anticipation in PTSD patients and controls in the striatum, dorsal anterior cingulate cortex and insula, key regions in the reward pathway. Although PTSD patients did not differ from controls in motivational processing under placebo, anhedonia severity in PTSD patients was negatively related to reward responsiveness in the ventral striatum. Furthermore, oxytocin effects on reward processing in the ventral striatum were positively associated with anhedonia.

CONCLUSIONS

Oxytocin administration increased reward pathway sensitivity during reward and loss anticipation in PTSD patients and trauma-exposed controls. Thus, oxytocin administration may increase motivation for goal-directed approach behavior in PTSD patients and controls, providing evidence for a neurobiological pathway through which oxytocin could potentially increase motivation and reward sensitivity in PTSD patients.

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.

The Social Salience Hypothesis of Oxytocin

Oxytocin is a nonapeptide that also serves as a neuromodulator in the human central nervous system. Over the last decade, a sizeable body of literature has examined its effects on social behavior in humans. These studies show that oxytocin modulates various aspects of social behaviors such as empathy, trust, in-group preference, and memory of socially relevant cues. Several theoretical formulations have attempted to explain the effects of oxytocin. The prosocial account argues that oxytocin mainly enhances affiliative prosocial behaviors; the fear/stress theory suggests that oxytocin affects social performance by attenuating stress; and the in-/out-group approach proposes that oxytocin regulates cooperation and conflict among humans in the context of intergroup relations. Nonetheless, accumulating evidence reveals that the effects of oxytocin are dependent on a variety of contextual aspects and the individual's characteristics and can induce antisocial effects including aggression and envy. In an attempt to reconcile these accounts, we suggest a theoretical framework that focuses on the overarching role of oxytocin in regulating the salience of social cues through its interaction with the dopaminergic system. Crucially, the salience effect modulates attention orienting responses to external contextual social cues (e.g., competitive vs. cooperative environment) but is dependent on baseline individual differences such as gender, personality traits, and degree of psychopathology. This view could have important implications for the therapeutic applications of oxytocin in conditions characterized with aberrant social behavior.

The Neurobiology Shaping Affective Touch: Expectation, Motivation, and Meaning in the Multisensory Context

Inter-individual touch can be a desirable reward that can both relieve negative affect and evoke strong feelings of pleasure. However, if other sensory cues indicate it is undesirable to interact with the toucher, the affective experience of the same touch may be flipped to disgust. While a broad literature has addressed, on one hand the neurophysiological basis of ascending touch pathways, and on the other hand the central neurochemistry involved in touch behaviors, investigations of how external context and internal state shapes the hedonic value of touch have only recently emerged. Here, we review the psychological and neurobiological mechanisms responsible for the integration of tactile “bottom–up” stimuli and “top–down” information into affective touch experiences. We highlight the reciprocal influences between gentle touch and contextual information, and consider how, and at which levels of neural processing, top-down influences may modulate ascending touch signals. Finally, we discuss the central neurochemistry, specifically the μ-opioids and oxytocin systems, involved in affective touch processing, and how the functions of these neurotransmitters largely depend on the context and motivational state of the individual.

Emotion, rationality, and decision-making: how to link affective and social neuroscience with social theory

In this paper, we argue for a stronger engagement between concepts in affective and social neuroscience on the one hand, and theories from the fields of anthropology, economics, political science, and sociology on the other. Affective and social neuroscience could provide an additional assessment of social theories. We argue that some of the most influential social theories of the last four decades-rational choice theory, behavioral economics, and post-structuralism-contain assumptions that are inconsistent with key findings in affective and social neuroscience. We also show that another approach from the social sciences-plural rationality theory-shows greater compatibility with these findings. We further claim that, in their turn, social theories can strengthen affective and social neuroscience. The former can provide more precise formulations of the social phenomena that neuroscientific models have targeted, can help neuroscientists who build these models become more aware of their social and cultural biases, and can even improve the models themselves. To illustrate, we show how plural rationality theory can be used to further specify and test the somatic marker hypothesis. Thus, we aim to accelerate the much-needed merger of social theories with affective and social neuroscience.

The influence of early life sexual abuse on oxytocin concentrations and premenstrual symptomatology in women with a menstrually related mood disorder

Oxytocin (OT), associated with affiliation and social bonding, social salience, and stress/pain regulation, may play a role in the pathophysiology of stress-related disorders, including menstrually-related mood disorders (MRMD's). Adverse impacts of early life sexual abuse (ESA) on adult attachment, affective regulation, and pain sensitivity suggest ESA-related OT dysregulation in MRMD pathophysiology. We investigated the influence of ESA on plasma OT, and the relationship of OT to the clinical phenomenology of MRMD's. Compared to MRMD women without ESA (n=40), those with ESA (n=20) displayed significantly greater OT [5.39pg/mL (SD, 2.4) vs. 4.36pg/mL (SD, 1.1); t (58)=-2.26, p=0.03]. In women with ESA, OT was significantly, inversely correlated with premenstrual psychological and somatic symptoms (r's=-0.45 to -0.64, p's<0.05). The relationship between OT and premenstrual symptomatology was uniformly low and non-significant in women without ESA. In women with ESA, OT may positively modulate MRMD symptomatology.

Hormones as "difference makers" in cognitive and socioemotional aging processes

Aging is associated with well-recognized alterations in brain function, some of which are reflected in cognitive decline. While less appreciated, there is also considerable evidence of socioemotional changes later in life, some of which are beneficial. In this review, we examine age-related changes and individual differences in four neuroendocrine systems-cortisol, estrogen, testosterone, and oxytocin-as "difference makers" in these processes. This suite of interrelated hormonal systems actively coordinates regulatory processes in brain and behavior throughout development, and their level and function fluctuate during the aging process. Despite these facts, their specific impact in cognitive and socioemotional aging has received relatively limited study. It is known that chronically elevated levels of the stress hormone cortisol exert neurotoxic effects on the aging brain with negative impacts on cognition and socioemotional functioning. In contrast, the sex hormones estrogen and testosterone appear to have neuroprotective effects in cognitive aging, but may decrease prosociality. Higher levels of the neuropeptide oxytocin benefit socioemotional functioning, but little is known about the effects of oxytocin on cognition or about age-related changes in the oxytocin system. In this paper, we will review the role of these hormones in the context of cognitive and socioemotional aging. In particular, we address the aforementioned gap in the literature by: (1) examining both singular actions and interrelations of these four hormonal systems; (2) exploring their correlations and causal relationships with aspects of cognitive and socioemotional aging; and (3) considering multilevel internal and external influences on these hormone systems within the framework of explanatory pluralism. We conclude with a discussion of promising future research directions.

Experimenter Effects on Pain Reporting in Women Vary across the Menstrual Cycle

Background. Separate lines of research have shown that menstrual cycling and contextual factors such as the gender of research personnel influence experimental pain reporting. Objectives. This study examines how brief, procedural interactions with female and male experimenters can affect experimentally reported pain (cold pressor task, CPT) across the menstrual cycle. Methods. Based on the menstrual calendars 94 naturally cycling women and 38 women using hormonal contraceptives (M age = 19.83,  SD = 3.09) were assigned to low and high fertility groups. This assignment was based on estimates of their probability of conception given their current cycle day. Experimenters (12 males, 7 females) engaged in minimal procedural interactions with participants before the CPT was performed in solitude. Results. Naturally cycling women in the high fertility group showed significantly higher pain tolerance (81 sec, d = .79) following interactions with a male but not a female experimenter. Differences were not found for women in the low fertility or contraceptive groups. Discussion. The findings illustrate that menstrual functioning moderates the effect that experimenter gender has on pain reporting in women. Conclusion. These findings have implications for standardizing pain measurement protocols and understanding how basic biopsychosocial mechanisms (e.g., person-perception systems) can modulate pain experiences.