Oxytocin reduces the link between neural and affective responses after social exclusion

Oxytocin modulates neural activity during early perceptual salience attribution

Leading hypotheses of oxytocin's (OT) role in human cognition posit that it enhances salience attribution. However, whether OT exerts its effects predominantly in social (vs non-social) contexts remains debatable, and the time-course of intranasal OT's effects' on salience attribution processing is still unknown. We used the social Salience Attribution Task modified (sSAT) in a double-blind, placebo-controlled intranasal OT (inOT) administration, between-subjects design, with 54 male participants, to test existing theories of OT's role in cognition. Namely, we aimed to test whether inOT would differently affect salience attribution processing of social stimuli (expressing fearfulness) and non-social stimuli (fruits) made relevant via monetary reinforcement, and its neural processing time-course. During electroencephalography (EEG) recording, participants made speeded responses to emotional social (fearful faces) and non-emotional non-social (fruits) stimuli - which were matched for task-relevant motivational salience through their (color-dependent) probability of monetary reinforcement. InOT affected early (rather than late, P3b and LPP) EEG components, increasing N170 amplitude (p = .041) and P2b latency (p .001; albeit not of P1), regardless of stimuli's (emotional) socialness or reinforcement probability. Fear-related socialness affected salience attribution processing EEG (p .05) across time (N170, P2b and P3b), being later modulated by reinforcement probability (LPP). Our data suggest that OT's effects on neural activity during early perception, may exist irrespective of fear-related social- or reward-contexts. This partially supports the tri-phasic model of OT (which posits OT enhances salience attribution in an early perception stage regardless of socialness), and not the social salience nor the general approach-withdrawal hypotheses of OT, for early salience processing event-related potentials.

Uncovering the underlying factors of ERP changes in the cyberball paradigm: A systematic review investigating the impact of ostracism and paradigm characteristics

The Cyberball is the most commonly employed paradigm for the investigation of the effects of social exclusion, also called ostracism. The analysis of event-related potentials (ERPs), short-term stimulus-induced fluctuations in the EEG signal, has been employed for the identification of time-sensitive neural responses to ostracism-related information. Changes in ERPs during the Cyberball are normally attributed to the effect of ostracism, but it has been argued that characteristics of the paradigm, not ostracism, are the driving force for these changes. To elucidate the origin of the ERP changes in the Cyberball, we systematically reviewed the Cyberball-ERP literature of healthy, adult populations, and evaluated whether the social context of ostracism or characteristics of the paradigm are better suited for the explanation of the found results. Our results show that for many components no clear origin can be identified, but that expectancy violations, not ostracism, best explains the results of the P3 complex. Future research should therefore also employ other paradigms for the research into the effects of ostracism on ERPs.

The effects of intranasal oxytocin on black participants’ responses to outgroup acceptance and rejection

Social acceptance (vs. rejection) is assumed to have widespread positive effects on the recipient; however, ethnic/racial minorities often react negatively to social acceptance by White individuals. One possibility for such reactions might be their lack of trust in the genuineness of White individuals’ positive evaluations. Here, we examined the role that oxytocin—a neuropeptide putatively linked to social processes—plays in modulating reactions to acceptance or rejection during interracial interactions. Black participants (N = 103) received intranasal oxytocin or placebo and interacted with a White, same-sex stranger who provided positive or negative social feedback. After positive feedback, participants given oxytocin (vs. placebo) tended to display approach-oriented cardiovascular responses of challenge (vs. threat), exhibited more cooperative behavior, and perceived the partner to have more favorable attitudes toward them after the interaction. Following negative feedback, oxytocin reduced anger suppression. Oxytocin did not modulate testosterone reactivity directly, but our exploratory analysis showed that the less participants suppressed anger during the interaction with their partner, the greater testosterone reactivity they displayed after the interaction. These results survived the correction for multiple testing with a false discovery rate (FDR) of 20%, but not with a rate of 10 or 5%. Discussion centers on the interplay between oxytocin and social context in shaping interracial interactions.

The pandemic should catalyze research on social pain: Examining oxytocin administration studies

For decades, researchers have tried to identify drugs that can decrease the painful feelings associated with social loss, rejection, or isolation. One effort has been to investigate whether the neuropeptide oxytocin reduces social pain. In this commentary, I examine intranasal oxytocin's effects on experimentally induced social exclusion. Future recommendations are presented with the goal of spurring new research efforts to elucidate the neurobiological mechanisms underlying the experience of social pain.

Oxytocin reduces romantic rejection-induced pain in online speed-dating as revealed by decreased frontal-midline theta oscillations

BACKGROUND

Romantic rejection is an emotionally distressful experience profoundly affecting life, possibly leading to mental illness or suicide. Oxytocin (OT) is a neuropeptide widely implicated in reducing physical pain and negative emotions; however, whether OT has an effect on reducing intense social pain (e.g., romantic rejection) remains unknown. Here, we tested the effect of OT on social pain and investigated its role in the outcome evaluation phase of social decision-making.

METHODS

Electroencephalographic recordings were obtained between August 2nd and October 20th, 2020 in Shenzhen University from 61 healthy participants in a double-blind, placebo-controlled study with a between-subject design. We defined frontal-midline theta oscillation as a neural signature of social pain and assessed self-reported pleasantness ratings for four possible romantic outcomes in an online speed-dating task.

RESULTS

In the placebo group, greater theta power was induced by romantic rejection, being associated with rejection distress. This pattern was not observed in the OT group, where romantic rejection induced significantly decreased theta power compared to the placebo group; in the OT group, there was no association between theta power and rejection distress. Furthermore, the frontal-midline theta oscillation could be source-localized to brain areas overlapping with the physical-social pain matrix (i.e., somatosensory cortex, anterior cingulate cortex, frontal pole, and supplementary motor area).

CONCLUSIONS

OT relieves social pain caused by romantic rejection, reflected in decreased frontal-midline theta oscillations and a diminished connection between theta power and rejection distress. These findings can help understand and harness OT's pain-reducing effect on social pain.

Does oxytocin shield against negative effects of ostracism? A replication and extension

Evidence collected in recent years suggests that OT can alleviate negative consequences of ostracism. However, it is unclear whether this effect requires favorable dispositions. Moreover, research is needed to replicate previous findings. We thus investigated whether a combination of OT and potentially leveraging traits shields against negative effects of ostracism in a direct and conceptual replication of previous work. Seventy-seven males, who varied on potential moderating features, were administered OT or a placebo, and were ostracized or included in the Cyberball paradigm. Results showed that OT tended to attenuate the drop in social comfort in response to ostracism, and induced participants, particularly those high in horizontal collectivism, to toss the ball more often toward an approaching co-player who had ostracized them earlier. Attachment avoidance did not moderate these effects. Thus, the study replicated OT's relieving effects on ostracism, but provided only partial support for the leveraging influence of person factors.

Social exclusion increases the executive function of attention networks

Previous studies in humans have shown that brain regions activating social exclusion overlap with those related to attention. However, in the context of social exclusion, how does behavioral monitoring affect individual behavior? In this study, we used the Cyberball game to induce the social exclusion effect in a group of participants. To explore the influence of social exclusion on the attention network, we administered the Attention Network Test (ANT) and compared results for the three subsystems of the attention network (orienting, alerting, and executive control) between exclusion (N = 60) and inclusion (N = 60) groups. Compared with the inclusion group, the exclusion group showed shorter overall response time and better executive control performance, but no significant differences in orienting or alerting. The excluded individuals showed a stronger ability to detect and control conflicts. It appears that social exclusion does not always exert a negative influence on individuals. In future research, attention to network can be used as indicators of social exclusion. This may further reveal how social exclusion affects individuals' psychosomatic mechanisms.

The OXTR polymorphisms are not associated with attachment dimensions: A three-approach study

Inspired by the roles of oxytocin in social behaviors, scientists have devoted considerable efforts to examine the association between the oxytocin receptor gene (OXTR) and human attachment, a personality of seek and receiving comfort from intimate figures. However, there are still a lot of controversies on the association. To clarify the relationship, this research integrated three studies: (1) A cross-sectional study indicated that the OXTR polymorphisms (i.e., rs53576 and rs2254298) were not significantly associated with attachment dimensions in a college student sample (N = 1193); (2) A three-wave study showed that the polymorphisms were not associated with the individual differences and changes of attachment dimensions in a freshmen sample (N = 657); and (3) Meta-analysis indicated that attachment dimensions were not associated with the polymorphisms of rs53576 (Anxiety: 14 samples, N = 5053; Avoidance: ten samples, N = 4273) and rs2254298 (Anxiety: ten samples, N = 3670; Avoidance: ten samples, N = 3698). Taken together, these findings provide strong evidence that the OXTR polymorphisms are not related to attachment dimensions.

Tri-Phasic Model ofOxytocin (TRIO): A systematic conceptual review of oxytocin-related ERP research

BACKGROUND

The neuropeptide oxytocin (OT) has been shown to play a role in variety of cognitive and social processes and different hypotheses have been put forth to explain OT's effects on brain and behavior in humans. However, these previous explanatory accounts do not provide information about OT-related temporal modulation in the brain.

OBJECTIVES

This paper systematically reviewed intranasal OT administration studies employing event-related potentials (ERPs) and synthesized the existing evidence into a novel conceptual framework.

METHODS

Empirical studies, published until February 2020 and cited in major databases (EBSCOhost, PubMed, and Web of Science), were examined in accordance with PRISMA guidelines. To be included, studies had to: (i) employ intranasal administration of OT, as the chemical modulator; (ii) measure ERPs; (iii) be peer-reviewed journal articles; (iv) be written in English; and (v) examine human participants.

RESULTS

The search criteria yielded 17 empirical studies. The systematic review resulted in conceptualization of the Tri-Phasic Model ofOxytocin (TRIO), which builds on three processing stages: (i) perception, (ii) selection, and (iii) evaluation. While OT increases attention irrespective of stimuli characteristics in the perception stage, in the selection and evaluation stages, OT acts as a filter to guide attention selectively towards social over non-social stimuli and modulates prosociality/approach motivation associated with social stimuli.

CONCLUSIONS

TRIO offers an empirically-derived conceptual framework that can guide the study of OT-related modulation on attentional processes, starting very early in the processing stream. This novel account furthers theoretical understanding and informs empirical investigation into OT modulation on the brain.

A Novel Role of CD38 and Oxytocin as Tandem Molecular Moderators of Human Social Behavior

Oxytocin is an important modulator of human affiliative behaviors, including social skills, human pair bonding, and friendship. CD38 will be discussed as an immune marker and then in more detail the mechanisms of CD38 on releasing brain oxytocin. Mention is made of the paralogue of oxytocin, vasopressin, that has often overlapping and complementary functions with oxytocin on social behavior. Curiously, vasopressin does not require CD38 to be released from the brain. This review discusses the social salience hypothesis of oxytocin action, a novel view of how this molecule influences much of human social behaviors often in contradictory ways. The oxytocinergic-vasopressinergic systems are crucial modulators of broad aspects of human personality. Of special interest are studies of these two hormones in trust related behavior observed using behavioral economic games. This review also covers the role of oxytocin in parenting and parental attachment. In conclusion, the effects of oxytocin on human behavior depend on the individual's social context and importantly as well, the individual's cultural milieu, viz. East and West. ACRONYMS: ACC = Anterior Cingulate ADP = Adenosine diphosphate AQ = Autism Quotient cADPR = Cyclic ADP-ribose CNS = Central nervous system DA = Dopamine eQTLC = Expression Quantitative Trait Loci LC-NE = Locus Coeruleus-Norepinephrine MRI = Magnetic Resonance Imaging OFC = Orbitofrontal cortices OXT = Oxytocin RAGE = Receptor for advanced glycation end-products SARM1 = Sterile Alpha and toll/interleukin-1 receptor motif-containing 1 TRPM2= Transient Receptor Potential Cation Channel Subfamily M Member 2 AVP = Vasopressin.