Self-other Integration Research Articles

Individual differences in music-induced interpersonal synchronization and self–other integration: the role of creativity and empathy

It has been demonstrated that moving together in synchrony to music makes us feel connected. Yet, little is known about the individual differences that shape the relationship between interpersonal synchronization to music and social bonding. The present research tests the hypothesis that this association is influenced by differences in empathy and creativity–two highly relevant factors in many musical activities. We implemented a synchronization task featuring a virtual drummer and measured self–other integration (SOI), a core component of social bonding. We employed a dual-measurement paradigm, incorporating both an explicit assessment ( Inclusion of Other in the Self scale) and an implicit assessment ( joint-Simon effect ) of SOI. Surprisingly, our analysis did not reveal explicit and implicit measurements correlating, nor were they similarly affected by interpersonal synchronization. This raises questions about the assessment of SOI in interpersonal synchronization experiments. Furthermore, we observed no moderating role of empathy or creativity in the association between interpersonal synchronization and SOI. Nevertheless, we found creativity to correlate with SOI. In light of this finding, we recommend placing greater emphasis on creativity as a decisive factor in the study of musical interaction.

Influence of interpersonal distance on collaborative performance in the joint Simon task—An fNIRS-based hyperscanning study

Collaboration is a critical skill in everyday life. It has been suggested that collaborative performance may be influenced by social factors such as interpersonal distance, which is defined as the perceived psychological distance between individuals. Previous literature has reported that close interpersonal distance may promote the level of self-other integration between interacting members, and in turn, enhance collaborative performance. These studies mainly focused on interdependent collaboration, which requires high levels of shared representations and self-other integration. However, little is known about the effect of interpersonal distance on independent collaboration (e.g., the joint Simon task), in which individuals perform the task independently while the final outcome is determined by the parties. To address this issue, we simultaneously measured the frontal activations of ninety-four pairs of participants using a functional near-infrared spectroscopy (fNIRS)-based hyperscanning technique while they performed a joint Simon task. Behavioral results showed that the Joint Simon Effect (JSE), defined as the RT difference between incongruent and congruent conditions indicating the level of self-other integration between collaborators, was larger in the friend group than in the stranger group. Consistently, the inter-brain neural synchronization (INS) across the dorsolateral and medial parts of the prefrontal cortex was also stronger in the friend group. In addition, INS in the left dorsolateral prefrontal cortex negatively predicted JSE only in the friend group. These results suggest that close interpersonal distance may enhance the shared mental representation among collaborators, which in turn influences their collaborative performance.

You, me, and us: Maintaining self-other distinction enhances coordination, agency, and affect

Coordinating our actions with others changes how we behave and feel. Here, we provide evidence that interacting with others rests on a balance between self-other integration and segregation. Using a group walking paradigm, participants were instructed to synchronize with a metronome while listening to the sounds of 8 virtual partners. By manipulating the similarity and synchronicity of the partners' steps to the participant's own, our novel auditory task disentangles the effects of synchrony and self-other similarity and examines their contribution to both collective and individual awareness. We measured temporal coordination (step timing regularity and synchrony with the metronome), gait patterns, and subjective reports about sense of self and group cohesion. The main findings show that coordination is best when participants hear distinct but synchronous virtual others, leading to greater subjective feelings of agency, strength, dominance, and happiness.

Joint action with human and robotic co-actors: Self-other integration is immune to the perceived humanness of the interacting partner.

When performing a joint action task, we automatically represent the action and/or task constraints of the co-actor with whom we are interacting. Current models suggest that, not only physical similarity, but also abstract, conceptual features shared between self and the interacting partner play a key role in the emergence of joint action effects. Across two experiments, we investigated the influence of the perceived humanness of a robotic agent on the extent to which we integrate the action of that agent into our own action/task representation, as indexed by the Joint Simon Effect (JSE). The presence (vs. absence) of a prior verbal interaction was used to manipulate robot's perceived humanness. In Experiment 1, using a within-participant design, we had participants perform the joint Go/No-go Simon task with two different robots. Before performing the joint task, one robot engaged in a verbal interaction with the participant and the other robot did not. In Experiment 2, we employed a between-participants design to contrast these two robot conditions as well as a human partner condition. In both experiments, a significant Simon effect emerged during joint action and its amplitude was not modulated by the humanness of the interacting partner. Experiment 2 further showed that the JSE obtained in robot conditions did not differ from that measured in the human partner condition. These findings contradict current theories of joint action mechanisms according to which perceived self-other similarity is a crucial determinant of self-other integration in shared task settings.

Individual differences in social interaction contexts: Examining the role of personality traits in the degree of self-other integration

There is increasing evidence in the joint action literature that the degree of self-other integration is sensitive to situational factors that affect the social interaction context. Until now, however, no study has addressed the potential role of dispositional factors such as personality traits in observed interindividual variations. The current study aims to address this gap. Using the joint Simon effect (JSE) as a measure of the degree of self-other integration, our results highlight that the magnitude of the JSE is consistently higher among participants with a high level of Extraversion and Agreeableness compared to those with a low level. This seems to indicate that extravert and agreeable people exhibit increased self-other integration, i.e., a greater propensity to integrate others' action representations. These results are the first experimental evidence that personality traits can mediate the degree of self-other integration in social interaction contexts. We discuss our findings, and suggest that considering individual differences would help to clarify inconsistent results reported in the joint action literature regarding the impact of certain situational factors on the degree of self-other integration.

Happiness connects: The impact of mood on self-other integration.

Converging evidence suggests a considerable plasticity of self-representation and self-other boundaries. But what are the factors controlling this plasticity? Here we explored how changes in an individual's affective state impact his/her self-other representation. Participants watched short videos to elicit happiness or sadness before rating unfamiliar faces with happy or sad expressions. After watching the happy video, participants showed more self-other integration of happy than sad faces, while watching the sad video reduced integration for both happy and sad faces equally. This finding suggests the interaction of two processes: Positive mood biases metacontrol toward flexibility, which fosters the processing of features in which self and other might overlap, and possible overlap increases self-other integration. Negative mood, in turn, biases metacontrol toward persistence, which focuses processing on strictly task-relevant feature dimensions, so that possible overlap is less likely to have an impact.

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.

Alpha oscillations related to self-other integration and distinction during live orchestral performance: A naturalistic case study.

Ensemble music performance requires musicians to achieve precise interpersonal coordination while maintaining autonomous control over their own actions. To do so, musicians dynamically shift between integrating other performers' actions into their own action plans and maintaining a distinction between their own and others' actions. Research in laboratory settings has shown that this dynamic process of self-other integration and distinction is indexed by sensorimotor alpha oscillations. The purpose of the current descriptive case study was to examine oscillations related to self-other integration and distinction in a naturalistic performance context. We measured alpha activity from four violinists during a concert hall performance of a 60-musician orchestra. We selected a musical piece from the orchestra's repertoire and, before analyzing alpha activity, performed a score analysis to divide the piece into sections that were expected to strongly promote self-other integration and distinction. In line with previous laboratory findings, performers showed suppressed and enhanced alpha activity during musical sections that promoted self-other integration and distinction, respectively. The current study thus provides preliminary evidence that findings from carefully controlled laboratory experiments generalize to complex real-world performance. Its findings also suggest directions for future research and potential applications of interest to musicians, music educators, and music therapists.

How vertical elevation affects self-other integration as measured by the joint Simon effect

Earlier findings suggest that positions of power decrease self-other integration and increase psychological distance to others. Until now, however, evidence for this relation rests exclusively on subjective measures. The current research instead employed a vertical joint Simon task to measure self-other integration. This task assesses the extent to which people represent their own actions in reference to their co-actor's, also referred to as the joint Simon effect. Building on cultural associations between power and vertical elevation, we manipulated whether participants were in an elevated (high-power) or lower (low-power) seating position. Experiments 1a and 1b reanalyzed existing datasets and found that elevated (vs. lower) seating position decreased the joint Simon effect, consistent with predictions. Experiment 2 provides a high-powered replication of this finding. Yet, further analyses revealed that feelings of power – measured as a manipulation check and indeed demonstrating that the manipulation was successful – did not mediate or moderate the effect of seating position on the joint Simon effect. Therefore, it is possible that the effect of seating elevation was driven through other aspects of that manipulation than feelings of power. We discuss these and suggest ways to test these alternative explanations.

Simultaneous self-other integration and segregation support real-time interpersonal coordination in a musical joint action task

The ability to distinguish between an individual's own actions and those of another person is a requirement for successful joint action, particularly in domains such as group music making where precise interpersonal coordination ensures perceptual overlap in the effects of co-performers' actions. We tested the hypothesis that such coordination benefits from simultaneous integration and segregation of information about ‘self’ and ‘other’ in an experiment using a musical joint action paradigm. Sixteen pairs of individuals with little or no musical training performed a dyadic synchronization task on a pair of electronic music boxes. The relationship between pitches produced by paired participants (same vs. different) and the relationship between movement frequencies required to trigger synchronous tones (congruent vs. incongruent) were varied in a repeated measures design. The results indicate that interpersonal coordination was most accurate when sounds were different in pitch but movement frequency was congruent. Under other conditions, participants often drifted apart, resulting in poor coordination, especially with same sounds and incongruent movements across co-performers. These findings suggest that interpersonal coordination was facilitated when simultaneous self-other integration and segregation occurred across sensory modalities in an asymmetrical manner where pitch relations favoured segregation via auditory streaming while movement congruence favoured integration via visuo-motor coupling. Such self-other representational balance may enable co-performers to maintain autonomous control while attending, anticipating, and adapting to each other's timing when joint action requires precise temporal coordination.

Self-partner inclusion predicts performance of romantically involved individuals in a body-scaled action-anticipation task.

Previous research has shown that romantic relationships can lead to the cognitive inclusion of a romantic partner into one’s own self-representation, resulting in blurred boundaries between self and intimate other. Recent work suggests that this self-other integration process encompasses the two dimensions of the self–the conceptual and the bodily self. In line with this, it has been proposed that romantic love is associated with cognitive states that blur or reduce the saliency of self-boundaries in the bodily domain. The present study tested this hypothesis by investigating the influence of the self-other integration process in romantic love on passability judgments of door-like apertures, an action-anticipation task that rests on the representation of bodily boundaries. Romantically involved and single participants estimated whether they could pass through apertures of different widths. Moreover, inclusion of romantic partner in the self was assessed using the Inclusion of Other in the Self (IOS) scale. The pattern of correlation and the ratio between participants’ shoulder width and aperture judgments did not differ between romantically involved participants and singles. However, our results revealed that in romantically involved participants, the relationship between individuals’ shoulder width and aperture judgements was moderated by IOS scores. A greater inclusion of romantic partner in the self was associated with a weaker prediction of aperture judgment by participants’ shoulder width. A similar moderating effect of the intensity of romantic feelings (as measured by the passionate love scale) on shoulder width-aperture judgment relationship was found. IOS scores, but not romantic feelings, also moderated aperture judgments made for another individual (third person perspective). Together, these findings are consistent with the view that inclusion of romantic partner in the self triggers cognitive states affecting self-boundaries in the bodily domain.

Abnormal ERPs and Brain Dynamics Mediate Basic Self Disturbance in Schizophrenia: A Review of EEG and MEG Studies.

Background: Interest in disordered sense of self in schizophrenia has recently re-emerged in the literature. It has been proposed that there is a basic self disturbance, underlying the diagnostic symptoms of schizophrenia, in which the person's sense of being a bounded individual continuous through time loses stability. This disturbance has been documented phenomenologically and at the level of cognitive tasks. However, the neural correlates of basic self disorder in schizophrenia are poorly understood.Methods: A search of PubMed was used to identify studies on self and schizophrenia that reported EEG or MEG data.Results: Thirty-three studies were identified, 32 using EEG and one using MEG. Their operationalizations of the self were divided into six paradigms: self-monitoring for errors, proprioception, self-other integration, self-referential processing, aberrant salience, and source monitoring. Participants with schizophrenia were less accurate on self-referential processing tasks and had slower response times across most studies. Event-related potential amplitudes differed across many early and late components, with reduced N100 suppression in source monitoring paradigms being the most replicated finding. Several studies found differences in one or more frequency band, but no coherent overall finding emerged in this area. Various other measures of brain dynamics also showed differences in single studies. Only some of the study designs were adequate to establish a causal relationship between the self and EEG or MEG measures.Conclusion: The broad range of changes suggests a global self disturbance at the neuronal level, possibly carried over from the resting state. Further studies that successfully isolate self-related effects are warranted to better understand the temporal-dynamic and spatial-topographic basis of self disorder and its relationship to basic self disturbance on the phenomenological level.

Metacontrol and joint action: how shared goals transfer from one task to another?

In most of our daily activities and in team sports, we interact with other individuals and do not act in isolation. Using a social variant of the standard two-choice Simon task, this study aims to test if competitive/cooperative processing modes (i.e., metacontrol states) change the degree of bodily self-other integration between two persons in joint action. In addition, and more exploratory the study tested if this effect depends on a shared group experience with the partner. Two participants shared a visual Simon task, so that each person basically performed complementary parts of the task, which transfers the paradigm into a go/no-go Simon task for each person. Before running this joint Simon task, we set both participants either in a competitive or a cooperative control state by means of a dyadic game, a manipulation aimed at testing possible goal transfer across tasks. We found significant joint Simon effects for participants who were in a competitive state and for participants who were in a cooperative state. The joint Simon effect for participants being in a competitive state was significantly smaller than for participants being in a cooperative state. When experiencing the goal induction together with the partner, the joint Simon effect was significantly decreased as when the induction was performed alone. Both effects (metacontrol state induction and shared experience) seem to be statistically independent of each other. In line with predictions of metacontrol state theory, our study indicated that abstract cognitive goal states can be transferred from one task to another task, able to affect the degree of bodily self-other integration across different task situations.

Mindfulness Meditation Weakens Attachment to Self: Evidence from a Self vs Other Binding Task

Mindfulness meditation is based on Buddhist teachings and meditation practices that promote a reduced identification with thoughts and mental states. Mindfulness meditation is also suggested to promote self-other integration, either by decreasing preference for self-related processing or by rebalancing self and other-related processing. However, it is not clear how meditation practice influences attachment to self and more specifically sense of agency. Hence, we investigated how mindfulness meditation (Vipassana or insight meditation) practice influences an implicit measure of sense of agency known as intentional binding effect with self- vs other-associated stimuli by comparing long-term meditators with non-meditators. This study had two phases. The first phase consisted of a perceptual matching task using self-related and other-related shape-label pairings so that participants can learn the shape-label associations. In the second phase, participants performed an intentional binding task with the same self-associated and other-associated stimuli displayed as target outcome of self-generated action. While meditators did show faster responses to self vs other shape-label processing similar to non-meditators, they did not show stronger binding (reduced temporal estimation between action and outcome shape) for self-associated compared with other-associated outcome. The results indicate that even though meditators preferentially process self-related information, they are less attached to self-associated stimuli as indicated by an implicit measure of sense of agency. These results have implications for theories of action and agency based on contemplative traditions that emphasize less attachment to outcomes of our actions.

Neural tracking and integration of ‘self’ and ‘other’ in improvised interpersonal coordination

Humans coordinate their movements with one another in a range of everyday activities and skill domains. Optimal joint performance requires the continuous anticipation of and adaptation to each other’s movements, especially when actions are spontaneous rather than pre-planned. Here we employ dual-EEG and frequency-tagging techniques to investigate how the neural tracking of self- and other-generated movements supports interpersonal coordination during improvised motion. LEDs flickering at 5.7 and 7.7 Hz were attached to participants’ index fingers in 28 dyads as they produced novel patterns of synchronous horizontal forearm movements. EEG responses at these frequencies revealed enhanced neural tracking of self-generated movement when leading and of other-generated movements when following. A marker of self-other integration at 13.4 Hz (inter-modulation frequency of 5.7 and 7.7 Hz) peaked when no leader was designated, and mutual adaptation and movement synchrony were maximal. Furthermore, the amplitude of EEG responses reflected differences in the capacity of dyads to synchronize their movements, offering a neurophysiologically grounded perspective for understanding perceptual-motor mechanisms underlying joint action.

A Kuramoto model of self-other integration across interpersonal synchronization strategies.

Human social behaviour is complex, and the biological and neural mechanisms underpinning it remain debated. A particularly interesting social phenomenon is our ability and tendency to fall into synchronization with other humans. Our ability to coordinate actions and goals relies on the ability to distinguish between and integrate self and other, which when impaired can lead to devastating consequences. Interpersonal synchronization has been a widely used framework for studying action coordination and self-other integration, showing that even in simple interactions, such as joint finger tapping, complex interpersonal dynamics emerge. Here we propose a computational model of self-other integration via within- and between-person action-perception links, implemented as a simple Kuramoto model with four oscillators. The model abstracts each member of a dyad as a unit consisting of two connected oscillators, representing intrinsic processes of perception and action. By fitting this model to data from two separate experiments we show that interpersonal synchronization strategies rely on the relationship between within- and between-unit coupling. Specifically, mutual adaptation exhibits a higher between-unit coupling than within-unit coupling; leading-following requires that the follower unit has a low within-unit coupling; and leading-leading occurs when two units jointly exhibit a low between-unit coupling. These findings are consistent with the theory of interpersonal synchronization emerging through self-other integration mediated by processes of action-perception coupling. Hence, our results show that chaotic human behaviour occurring on a millisecond scale may be modelled using coupled oscillators.

Common and unique effects of HD-tDCS to the social brain across cultural groups

Cultural background influences social cognition, however no study has examined brain stimulation differences attributable to cultural background. 104 young adults [52 South-East Asian Singaporeans (SEA); 52 Caucasian Australians (CA)] received anodal high-definition transcranial direct current stimulation (HD-tDCS) to the dorsomedial prefrontal cortex (dmPFC) or the right temporoparietal junction (rTPJ). Participants completed tasks with varying demands on self-other processing including visual perspective taking (VPT)and episodic memory with self and other encoding. At baseline, SEA showed greater self-other integration than CA in the level one (line-of-sight) VPT task as indexed by greater interference from the alternate perspective. Anodal HD-tDCS to the dmPFC resulted in the CA performing closer to the SEA during egocentric perspective judgements. Baseline performance on level two (embodied rotation) VPT task and the self-reference effect (SRE) in episodic memory was comparable between the two groups. In the combined sample, HD-tDCS to the rTPJ decreased the interference from the egocentric perspective during level two VPT and dmPFC HD-tDCS removed the SRE in episodic memory. Stimulation effects were comparable when baseline performance was comparable. When baseline performance differed, stimulation differences were identified. Therefore, social cognitive differences due to cultural background are an important consideration in social brain stimulation studies.

Dancing Chief in the Brain or Consciousness as an Entanglement

Free will in intentional consciousness is exposed to skeptics since it was found that subconscious neural activities, what is called readiness potential, precedes the intention to an action. The question of whether free will is an authentic illusion has been argued not only in psychology but physics and philosophy. Most of scientists, however, think that the intentional consciousness who believes to have his/her own free will, is determined by readiness potential in advance, and that free will cannot coexist with determinism. We here point out that knowing to be determined in advance cannot be verified till local event at a local site can be known from a different local site without disturbing the event. That is the assumption of locality. We here show that determinism, free will and locality are three essential elements in consciousness, and show that they constitute trilemma. The fact that one of three elements must be abandoned can lead to three types of consciousness. Absence of free will can constitute type I consciousness which is consistent with symptoms in autism spectrum disorder such as weakened theory of mind. Absence of determinism can constitute type II consciousness which is consistent with symptoms in schizophrenia such as thought insertion, self-other integration. Absence of locality can constitute type III consciousness which is consistent with typical people. We can find the entanglement of intentional consciousness with unconsciousness including readiness potential only in type III consciousness. Finally, we show that sense of agency and free will cannot be established until consciousness as an entanglement is implemented.

Mindfulness for adulting

ABSTRACTThis paper calls for ethical responsibility to manifest a holistic, embodied, and deeply relational vision of what it means to actualise fuller human flourishing than how we, humanity as a whole, are behaving currently. A thesis is presented that humanity is experiencing an arrest within the trajectory of species’ psychological development and that mindfulness cultivation can facilitate transformation. This thesis comes with a proviso that mindfulness needs to be taken up differently from the dominant discourse around it. A case is made that contemporary mindfulness is most often implicitly and explicitly fuelled by conventional “ordinary consciousness” whose primary function is survival supported by the fear-driven fight–flight–freeze neural assemblage. Suggestions are made that mindfulness be understood as a way of accessing non-ordinary consciousness that sees the world relationally in terms of expansive self-other integration. For this, further suggestions are made that mindfulness be placed back into a larger context, for example, practice-based Buddhist philosophy and psychology, that addresses existential suffering and proffers a comprehensive holistic educational programme. Such a programme cultivates human potential and supports relationally generous and generative human flourishing. As a concrete practice proposal for transitioning into a relational paradigm, inner work is proposed and illustrated with examples.

Your perspective and my benefit: multiple lesion models of self-other integration strategies during social bargaining.

Recursive social decision-making requires the use of flexible, context-sensitive long-term strategies for negotiation. To succeed in social bargaining, participants' own perspectives must be dynamically integrated with those of interactors to maximize self-benefits and adapt to the other's preferences, respectively. This is a prerequisite to develop a successful long-term self-other integration strategy. While such form of strategic interaction is critical to social decision-making, little is known about its neurocognitive correlates. To bridge this gap, we analysed social bargaining behaviour in relation to its structural neural correlates, ongoing brain dynamics (oscillations and related source space), and functional connectivity signatures in healthy subjects and patients offering contrastive lesion models of neurodegeneration and focal stroke: behavioural variant frontotemporal dementia, Alzheimer's disease, and frontal lesions. All groups showed preserved basic bargaining indexes. However, impaired self-other integration strategy was found in patients with behavioural variant frontotemporal dementia and frontal lesions, suggesting that social bargaining critically depends on the integrity of prefrontal regions. Also, associations between behavioural performance and data from voxel-based morphometry and voxel-based lesion-symptom mapping revealed a critical role of prefrontal regions in value integration and strategic decisions for self-other integration strategy. Furthermore, as shown by measures of brain dynamics and related sources during the task, the self-other integration strategy was predicted by brain anticipatory activity (alpha/beta oscillations with sources in frontotemporal regions) associated with expectations about others' decisions. This pattern was reduced in all clinical groups, with greater impairments in behavioural variant frontotemporal dementia and frontal lesions than Alzheimer's disease. Finally, connectivity analysis from functional magnetic resonance imaging evidenced a fronto-temporo-parietal network involved in successful self-other integration strategy, with selective compromise of long-distance connections in frontal disorders. In sum, this work provides unprecedented evidence of convergent behavioural and neurocognitive signatures of strategic social bargaining in different lesion models. Our findings offer new insights into the critical roles of prefrontal hubs and associated temporo-parietal networks for strategic social negotiation.