Effort expenditure modulates feedback evaluations involving self-other agreement: evidence from brain potentials and neural oscillations.

The influence of effort expenditure on the subjective value in feedback involving material reward has been the focus of previous research. However, little is known about the impact of effort expenditure on subjective value evaluations when feedback involves reward that is produced in the context of social interaction (e.g. self-other agreement). Moreover, how effort expenditure influences confidence (second-order subjective value) in feedback evaluations remains unclear. Using electroencephalography, this study aimed to address these questions. Event-related potentials showed that, after exerting high effort, participants exhibited increased reward positivity difference in response to self-other (dis)agreement feedback. After exerting low effort, participants reported high confidence, and the self-other disagreement feedback evoked a larger P3a. Time-frequency analysis showed that the high-effort task evoked increased frontal midline theta power. In the low (vs. high)-effort task, the frontal midline delta power for self-other disagreement feedback was enhanced. These findings suggest that, at the early feedback evaluation stage, after exerting high effort, individuals exhibit an increased sensitivity of subjective value evaluation in response to self-other agreement feedback. At the later feedback evaluation stage, after completing the low-effort task, the self-other disagreement feedback violates the individuals'high confidence and leads to a metacognitive mismatch.

The Causal Role of Temporoparietal Junction in Mediating Self-Other Mergence during Mentalizing.

Mentalizing is a core faculty of human social behaviors that involves inferring the cognitive states of others. This process necessitates adopting an allocentric perspective and suppressing one's egocentric perspective, referred to as self-other distinction (SOD). Meanwhile, individuals may project their own cognitive states onto others in prosocial behaviors, a process known as self-other mergence (SOM). It remains unclear how the two opposing processes coexist during mentalizing. We here combined functional magnetic resonance imaging (fMRI) and repetitive transcranial magnetic stimulation (rTMS) techniques with intranasal oxytocin (OTint) as a probe to examine the SOM effect in healthy male human participants, during which they attributed the cognitive states of decision confidence to an anonymous partner. Our results showed that OTint facilitated SOM via the left temporoparietal junction (lTPJ), but did not affect neural representations of internal information about others' confidence in the dorsomedial prefrontal cortex, which might be dedicated to SOD, although the two brain regions, importantly, have been suggested to be involved in mentalizing. Further, the SOM effect induced by OTint was fully mediated by the lTPJ activities and became weakened when the lTPJ activities were suppressed by rTMS. These findings suggest that the lTPJ might play a vital role in mediating SOM during mentalizing.SIGNIFICANCE STATEMENT Every human mind is unique. It is critical to distinguish the minds of others from the self. On the contrary, we often project the current mental states of the self onto others; that is to say, self-other mergence (SOM). The neural mechanism underlying SOM remains unclear. We here used intranasal oxytocin (OTint) as a probe to leverage SOM, which is typically suppressed during mentalizing. We revealed that OTint specifically modulated the left temporoparietal junction (lTPJ) neural activities to fully mediate the SOM effect, while suppressing the lTPJ neural activities by transcranial magnetic stimulations causally attenuated the SOM effect. Our results demonstrate that the lTPJ might mediate SOM during social interactions.

Oxytocin modulates social brain network correlations in resting and task state.

The effects of oxytocin (OT) on the social brain can be tracked upon assessing the neural activity in resting and task states, and developing a system-level framework for characterizing the state-based functional relationships of its distinct effect. Here, we contribute to this framework by examining how OT modulates social brain network correlations during resting and task states, using fMRI. First, we investigated network activation, followed by an analysis of the relationships between networks and individual differences. Subsequently, we evaluated the functional connectivity in both states. Finally, the relationship between networks across states was represented by the predictive power of networks in the resting state for task-evoked activities. The differences in the predicted accuracy between the subjects displayed individual variations in this relationship. Our results showed that the activity of the dorsal default mode network in the resting state had the largest predictive power for task-evoked activation of the precuneus network (PN) only in the OT group. The results also demonstrated that OT reduced the individual variation in PN in the prediction process. These findings suggest a distributed but modulatory effect of OT on the association between resting and task-dependent brain networks.

The role of oxytocin in modulating self-other distinction in human brain: a pharmacological fMRI study.

Self-other distinction is crucial for human interaction. Although with conflicting results, studies have found that oxytocin (OT) sharpens the self-other perceptual boundary. However, little is known about the effect of OT on self-other perception, especially its neural basis. Moreover, it is unclear whether OT influences self-other discrimination when the other is a child or an adult. This double-blind, placebo-controlled study investigated the effect of OT on self-face perception at the behavioral and neural levels. For the stimuli, we morphed participants' faces and child or adult strangers' faces, resulting in 4 conditions. After treatment with either OT or placebo, participants reported whether a stimulus resembled themselves while being scanned using functional magnetic resonance imaging (fMRI). Behavioral results showed that people judged adult-morphed faces better than child-morphed faces. Moreover, fMRI results showed that the OT group exhibited increased activity in visual areas and the inferior frontal gyrus for self-faces. This difference was more pronounced in the adult-face condition. In multivariate fMRI and region of interest analyses, better performance in the OT group indicated that OT increased self-other distinction, especially for adult faces and in the left hemisphere. Our study shows a significant effect of OT on self-referential processes, proving the potential effect of OT on a left hemisphere self-network.

Cortico-cerebellar audio-motor regions coordinate self and other in musical joint action.

Joint music performance requires flexible sensorimotor coordination between self and other. Cognitive and sensory parameters of joint action-such as shared knowledge or temporal (a)synchrony-influence this coordination by shifting the balance between self-other segregation and integration. To investigate the neural bases of these parameters and their interaction during joint action, we asked pianists to play on an MR-compatible piano, in duet with a partner outside of the scanner room. Motor knowledge of the partner's musical part and the temporal compatibility of the partner's action feedback were manipulated. First, we found stronger activity and functional connectivity within cortico-cerebellar audio-motor networks when pianists had practiced their partner's part before. This indicates that they simulated and anticipated the auditory feedback of the partner by virtue of an internal model. Second, we observed stronger cerebellar activity and reduced behavioral adaptation when pianists encountered subtle asynchronies between these model-based anticipations and the perceived sensory outcome of (familiar) partner actions, indicating a shift towards self-other segregation. These combined findings demonstrate that cortico-cerebellar audio-motor networks link motor knowledge and other-produced sounds depending on cognitive and sensory factors of the joint performance, and play a crucial role in balancing self-other integration and segregation.

Malleability of the sense of bodily self in early childhood: 5- and 6-year-old children show the enfacement illusion.

The mechanisms underlying the developing sense of bodily self are debated. Whereas some scholars stress the role of sensory factors, others propose the importance of contextual factors. By manipulating multisensory stimulation and social familiarity with the other person, we explored two factors that are proposed to relate to young children's developing sense of bodily self. Including an adult sample allowed us to investigate age-related differences of the malleability of the bodily self. To this end, the study implemented an enfacement illusion with children (N = 64) and adults (N = 33). Participants were exposed to one trial with synchronous interpersonal multisensory stimulation and one trial with asynchronous interpersonal multisensory stimulation-either with a stranger or with the mother as the other person. A self-recognition task using morph videos of self and other and an enfacement questionnaire were implemented as dependent measures. Results revealed evidence for the presence of the enfacement effect in children in both measures. The identity of the other person had a significant effect on the self-recognition task. Contrary to our hypothesis, the effect was significantly smaller in the caregiver condition. No significant differences between children and adults emerged. Our results demonstrate the role of both multisensory stimulation and contextual-here social familiarity-factors for the construction and development of a bodily self. The study provides developmental science with a novel approach to the bodily self by showing the validity of the self-recognition task in a child sample. Overall, the study supports proposals that the sense of bodily self is malleable early in development.

Exploring the acquaintanceship effect for the accuracy of judgments of traits and profiles of adult playfulness.

OBJECTIVE: We aimed to extend the research on the interpersonal perception of adult playfulness (global and facets: Other-directed, Lighthearted, Intellectual, and Whimsical [OLIW]) by testing whether judgmental accuracy relates to indicators of acquaintanceship. BACKGROUND: Playfulness has been found to contribute to social relationships. METHOD: Using data from 658 dyads (1,318 participants) who had been acquainted for 1 month to 62.2 years, we computed measurement invariance analyses and self-other agreement (SOA) for the facets and profiles of playfulness. We operationalized acquaintanceship as length of acquaintanceship, relationship type (friends, family, and partners), and intensity of acquaintanceship. We tested acquaintanceship effects with multigroup latent analyses and response surface analyses. RESULTS: Self- and other ratings of playfulness showed scalar measurement invariance and robust SOA in traits and distinctive profiles (≥ .37). There was only minor evidence for acquaintanceship effects for relationship duration (only Intellectual playfulness), and group comparisons showed that friends yielded lower SOA in profiles than dyads of family members and couples. CONCLUSION: Considering that playfulness can be accurately perceived even at zero acquaintance, we discuss whether playfulness is a "good trait" (high trait visibility) in which acquaintanceship plays a minor role. We also discuss methodological considerations for detecting acquaintanceship effects during relationship formation.

Whose emotion is it? Perspective matters to understand brain-body interactions in emotions.

Feeling happy, or judging whether someone else is feeling happy are two distinct facets of emotions that nevertheless rely on similar physiological and neural activity. Differentiating between these two states, also called Self/Other distinction, is an essential aspect of empathy, but how exactly is it implemented? In non-emotional cognition, the transient neural response evoked at each heartbeat, or heartbeat evoked response (HER), indexes the self and signals Self/Other distinction. Here, using electroencephalography (n = 32), we probe whether HERs' role in Self/Other distinction extends also to emotion - a domain where brain-body interactions are particularly relevant. We asked participants to rate independently validated affective scenes, reporting either their own emotion (Self) or the emotion expressed by people in the scene (Other). During the visual cue indicating to adopt the Self or Other perspective, before the affective scene, HERs distinguished between the two conditions, in visual cortices as well as in the right frontal operculum. Physiological reactivity (facial electromyogram, skin conductance, heart rate) during affective scene co-varied as expected with valence and arousal ratings, but also with the Self- or Other- perspective adopted. Finally, HERs contributed to the subjective experience of valence in the Self condition, in addition to and independently from physiological reactivity. We thus show that HERs represent a trans-domain marker of Self/Other distinction, here specifically contributing to experienced valence. We propose that HERs represent a form of evidence related to the 'I' part of the judgement 'To which extent do I feel happy'. The 'I' related evidence would be combined with the affective evidence collected during affective scene presentation, accounting at least partly for the difference between feeling an emotion and identifying it in someone else.

Atypical emotion sharing in individuals with mirror sensory synaesthesia.

Being able to empathise with others is a crucial ability in everyday life. However, this does not usually entail feeling the pain of others in our own bodies. For individuals with mirror-sensory synaesthesia (MSS), however, this form of empathic embodiment is a common feature. Our study investigates the empathic ability of adults who experience MSS using a video-based empathy task. We found that MSS participants did not differ from controls on emotion identification and affective empathy; however, they showed higher affect sharing (degree to which their affect matches what they attribute to others) than controls. This finding indicates difficulties with self-other distinction, which our data shows results in fewer signs of prosocial behaviour. Our findings are in line with the self-other control theory of MSS and highlight how the use of appropriate empathy measures can contribute to our understanding of this important socio-affective ability, both in typical and atypical populations.

The performance monitoring system is attuned to others' actions during dyadic motor interactions.

Interpersonal motor interactions require the simultaneous monitoring of one's own and one's partner's actions. To characterize how the action monitoring system tracks self and other behavior during synchronous interactions, we combined electroencephalography recordings and immersive virtual reality in two tasks where participants were asked to synchronize their actions with those of a virtual partner (VP). The two tasks differed in the features to be monitored: the Goal task required participants to predict and monitor the VP's reaching goal; the Spatial task required participants to predict and monitor the VP's reaching trajectory. In both tasks, the VP performed unexpected movement changes to which the participant needed to adapt. By extracting the neural activity locked to the detection of unexpected changes in the VP's action (other-monitoring) or to the participants' action-replanning (self-monitoring), we show that the monitoring system is more attuned to others' than to one's own actions. Additionally, distinctive neural responses to VP's unexpected goals and trajectory corrections were found: goal changes were reflected both in early fronto-central and later posterior neural responses while trajectory deviations were reflected only in later posterior responses. Altogether, our results indicate that the monitoring system adopts an inherent social mode to handle interpersonal motor interactions.

EEG Spatiotemporal Patterns Underlying Self-other Voice Discrimination.

There is growing evidence showing that the representation of the human "self" recruits special systems across different functions and modalities. Compared to self-face and self-body representations, few studies have investigated neural underpinnings specific to self-voice. Moreover, self-voice stimuli in those studies were consistently presented through air and lacking bone conduction, rendering the sound of self-voice stimuli different to the self-voice heard during natural speech. Here, we combined psychophysics, voice-morphing technology, and high-density EEG in order to identify the spatiotemporal patterns underlying self-other voice discrimination (SOVD) in a population of 26 healthy participants, both with air- and bone-conducted stimuli. We identified a self-voice-specific EEG topographic map occurring around 345 ms post-stimulus and activating a network involving insula, cingulate cortex, and medial temporal lobe structures. Occurrence of this map was modulated both with SOVD task performance and bone conduction. Specifically, the better participants performed at SOVD task, the less frequently they activated this network. In addition, the same network was recruited less frequently with bone conduction, which, accordingly, increased the SOVD task performance. This work could have an important clinical impact. Indeed, it reveals neural correlates of SOVD impairments, believed to account for auditory-verbal hallucinations, a common and highly distressing psychiatric symptom.

Self-other agreement and criterion-related validity of moral pride and hubris.

OBJECTIVES: This research investigates the moral implications of trait-level moral pride and hubris, addressing prior limitations by gathering data from multiple sources. We raise two interrelated questions: (1) Do well-acquainted peers agree with their friends on judgments of trait-level moral pride and hubris? (2) Are moral pride and hubris related to divergent (im)moral outcomes, regardless of measurement sources? METHOD: We collected data from a sample of university students and their friends (N = 173 dyads) in Hong Kong to examine self-other agreement and criterion-related validity of trait-level moral pride and hubris. RESULTS: Our findings reveal a medium-to-large level of self-other agreement for, as well as a moral divergence of, trait-level moral pride and hubris. Notably, self-reports of moral pride predict prosocial behavior, whereas self-reports of moral hubris predict virtue-signaling behavior, regardless of whether the outcomes are self- or other-reported. Moreover, self-reports trump other-reports in predicting some outcomes, but the reverse is true for other outcomes. CONCLUSIONS: Our findings suggest that individuals' proneness to experience morally specific pride and hubris constitutes "real" traits, evoking divergent (im)moral outcomes. Furthermore, self- and other-reports each contain some unique trait-relevant information, with their relative predictive power depending on the specific predictor and outcome.

Studying trait-characteristics and neural correlates of the emotional ego- and altercentric bias using an audiovisual paradigm.

In social interactions, emotional biases can arise when the emotional state of oneself and another person are incongruent. A person's ability to judge the other's emotional state can then be biased by their own emotional state, leading to an emotional egocentric bias (EEB). Alternatively, a person's perception of their own emotional state can be biased by the other's emotional state leading to an emotional altercentric bias (EAB). Using a modified audiovisual paradigm, we examined in three studies (n = 171; two online & one lab-based study) whether emotional biases can be considered traits by measuring two timepoints within participant and relating empathy trait scores to emotional biases, as well as the electrophysiological correlates of emotional biases. In all studies, we found a congruency effect, reflecting an EEB and EAB of small size. Both biases failed to correlate significantly within participants across timepoints and did not display significant relationships with empathy trait scores. On the electrophysiological level, we did not find any neural emotional bias effects in the time-frequency domain. Our results suggest that EEB and EAB effects are strongly task sensitive. Caution is warranted when studying interindividual differences in emotional biases using this paradigm, as they did not show significant test-retest reliabilities.

Differences in working memory coding of biological motion attributed to oneself and others.

The question how the brain distinguishes between information about self and others is of fundamental interest to both philosophy and neuroscience. In this functional magnetic resonance imaging (fMRI) study, we sought to distinguish the neural substrates of representing a full-body movement as one's movement and as someone else's movement. Participants performed a delayed match-to-sample working memory task where a retained full-body movement (displayed using point-light walkers) was arbitrarily labeled as one's own movement or as performed by someone else. By using arbitrary associations we aimed to address a limitation of previous studies, namely that our own movements are more familiar to us than movements of other people. A searchlight multivariate decoding analysis was used to test where information about types of movement and about self-association was coded. Movement specific activation patterns were found in a network of regions also involved in perceptual processing of movement stimuli, however not in early sensory regions. Information about whether a memorized movement was associated with the self or with another person was found to be coded by activity in the left middle frontal gyrus (MFG), left inferior frontal gyrus (IFG), bilateral supplementary motor area, and (at reduced threshold) in the left temporoparietal junction (TPJ). These areas are frequently reported as involved in action understanding (IFG, MFG) and domain-general self/other distinction (TPJ). Finally, in univariate analysis we found that selecting a self-associated movement for retention was related to increased activity in the ventral medial prefrontal cortex.

Bodily self-recognition in patients with pathological embodiment.

The ability to discriminate between one's own and others' body parts can be lost after brain damage, as in patients who misidentify someone else's hand as their own (pathological embodiment). Surprisingly, these patients do not use visual information to discriminate between the own and the alien hand. We asked whether this impaired visual discrimination emerges only in the ecological evaluation when the pathological embodiment is triggered by the physical alien hand (the examiner's one) or whether it emerges also when hand images are displayed on a screen. Forty right brain-damaged patients, with (E+ = 20) and without (E- = 20) pathological embodiment, and 24 healthy controls underwent two tasks in which stimuli depicting self and other hands was adopted. In the Implicit task, where participants judged which of two images matched a central target, the self-advantage (better performance with Self than Other stimuli) selectively emerges in controls, but not in patients. Moreover, E+ patients show a significantly lower performance with respect to both controls and E- patients, whereas E- patients were comparable to controls. In the Explicit task, where participants judged which stimuli belonged to themselves, both E- and E+ patients performed worst when compared to controls, but only E+ patients hyper-attributed others' hand to themselves (i.e., false alarms) as observed during the ecological evaluation. The VLSM revealed that SLF damage was significantly associated with the tendency of committing false alarm errors. We demonstrate that, in E+ patients, the ability to visually recognize the own body is lost, at both implicit and explicit level.

Underestimating Counterparts' Learning Goals Impairs Conflictual Conversations.

Given the many contexts in which people have difficulty engaging with views that disagree with their own-from political discussions to workplace conflicts-it is critical to understand how conflictual conversations can be improved. Whereas previous work has focused on strategies to change individual-level mindsets (e.g., encouraging open-mindedness), the present study investigated the role of partners' beliefs about their counterparts. Across seven preregistered studies (N = 2,614 adults), people consistently underestimated how willing disagreeing counterparts were to learn about opposing views (compared with how willing participants were themselves and how willing they believed agreeing others would be). Further, this belief strongly predicted greater derogation of attitude opponents and more negative expectations for conflictual conversations. Critically, in both American partisan politics and the Israeli-Palestinian conflict, a short informational intervention that increased beliefs that disagreeing counterparts were willing to learn about one's views decreased derogation and increased willingness to engage in the future. We built on research recognizing the power of the situation to highlight a fruitful new focus for conflict research.

Understanding the self in relation to others: Infants spontaneously map another's face to their own at 16-26 months.

The current study probed whether infants understand themselves in relation to others. Infants aged 16-26 months (n = 102) saw their parent wearing a sticker on their forehead or cheek, depending on experimental condition, placed unwitnessed by the child. Infants then received a sticker themselves, and their spontaneous behavior was coded. Regardless of age, from 16 months, all infants who placed the sticker on their cheek or forehead, placed it on the location on their own face matching their parent's placement. This shows that infants as young as 16 months of age have an internal map of their face in relation to others that they can use to guide their behavior. Whether infants placed the sticker on the matching location was related to other measures associated with self-concept development (the use of their own name and mirror self-recognition), indicating that it may reflect a social aspect of children's developing self-concept, namely their understanding of themselves in relation and comparison to others. About half of the infants placed the sticker on themselves, while others put it elsewhere in the surrounding, indicating an additional motivational component to bring about on themselves the state, which they observed on their parent. Together, infants' placement of the sticker in our task suggests an ability to compare, and motivation to align, self and others.

An integrative perspective on the role of touch in the development of intersubjectivity.

Touch concerns a fundamental component of sociality. In this review, we examine the hypothesis that somatomotor development constitutes a crucial psychophysiological element in the ontogeny of intersubjectivity. An interdisciplinary perspective is provided on how the communication channel of touch contributes to the sense of self and extends to the social self. During gestation, the transformation of random movements into organized sequences of actions with sensory consequences parallels the development of the brain's functional architecture. Brain subsystems shaped by the coordinated activity of somatomotor circuits to support these first body-environment interactions are the first brain functional arrangements to develop. We propose that tactile self-referring behaviour during gestation constitutes a prototypic mode of interpersonal exchange that supports the subsequent development of intersubjective exchange. The reviewed research suggests that touch constitutes a pivotal bodily experience that in early stages builds and later filters self-other interactions. This view is corroborated by the fact that aberrant social-affective touch experiences appear fundamentally associated with attachment anomalies, interpersonal trauma, and personality disorders. Given the centrality of touch for the development of intersubjectivity and for psychopathological conditions in the social domain, dedicated research is urged to elucidate the role of touch in the evolution of subjective self-other coding.

Observed shyness leads to more automatic imitation in early childhood.

The authors investigated children's automatic imitation in the context of observed shyness by adapting the widely used automatic imitation task (AIT). AIT performance in 6-year-old children (N = 38; 22 female; 71% White) and young adults (17-22 years; N = 122; 99 female; 32% White) was first examined as a proof of concept and to assess age-related differences in responses to the task (Experiment 1). Although error rate measures of automatic imitation were comparable between children and adults, children displayed less reaction time interference than adults. Children's shyness coded from direct behavioral observations was then examined in relation to AIT scores (Experiment 2). Observed shyness at 5 years old predicted higher automatic imitation one year later. We discuss the latter findings in the context of an adaptive strategy. We argue that shy children may possess a heightened sensitivity to others' motor cues and therefore are more likely to implicitly imitate social partners' actions. This tendency may serve as a strategy to signal appeasement and affiliation, allowing for shy children to blend in and feel less inhibited in a social environment.

Inclusion of the other in the self as a potential risk factor for prolonged grief disorder: A comparison of patients with matched bereaved healthy controls.

Pathological grief has received increasing attention in recent years, as about 10% of the bereaved suffer from one kind of it. Pathological grief in the form of prolonged grief disorder (PGD) is a relatively new diagnostic category which will be included into the upcoming ICD-11. To date, various risk and protective factors, as well as treatment options for pathological grief, have been proposed. Nevertheless, empirical evidence in that area is still scarce. Our aim was to identify the association of interpersonal closeness with the deceased and bereavement outcome. Interpersonal closeness with the deceased in 54 participants (27 patients suffering from PGD and 27 bereaved healthy controls) was assessed as the overlap of pictured identities via the inclusion of the other in the self scale (IOS scale). In addition to that, data on PGD symptomatology, general mental distress and depression were collected. Patients suffering from PGD reported higher inclusion of the deceased in the self. By contrast, they reported feeling less close towards another living close person. Results of the IOS scale were associated with PGD severity, general mental distress and depression. Inclusion of the deceased in the self is a significant statistical predictor for PGD caseness.