Self-other Distinction Research Articles

The Extrastriate Body Area and identity processing: An fMRI guided TMS study.

The extrastriate body area (EBA) is a body‐selective focal region located in the lateral occipito‐temporal cortex that responds strongly to images of human bodies and body parts in comparison with other classes of stimuli. Whether EBA contributes also to the body recognition of self versus others remains in debate. We investigated whether EBA contributes to self‐other distinction and whether there might be a hemispheric‐side specificity to that contribution using double‐pulse transcranial magnetic stimulation (TMS) in right‐handed participants. Prior to the TMS experiment, all participants underwent an fMRI localizer task to determine individual EBA location. TMS was then applied over either right EBA, left EBA or vertex, while participants performed an identification task in which images of self or others' right, or left hands were presented. TMS over both EBAs slowed responses, with no identity‐specific effect. However, TMS applied over right EBA induced significantly more errors on other's hands than noTMS, TMS over left EBA or over the Vertex, when applied at 100–110 ms after image onset. The last three conditions did not differ, nor was there any difference for self‐hands. These findings suggest that EBA participates in self/other discrimination.

Socio-cognitive training impacts emotional and perceptual self-salience but not self-other distinction

Training to inhibit imitative tendencies has been shown to reduce self-other interferences in both automatic imitation and perspective taking, suggesting that an enhancement of self-other distinction is transferrable from the motor to the cognitive domain. This study examined whether socio-cognitive training specifically enhances self-other distinction, or rather modulates self-salience, that is, the relative attentional priority of information pertaining to the self-perspective over information pertaining to the other person's perspective. Across two experiments, participants trained on one day to either imitate, inhibit imitation, inhibit control stimuli, or they were imitated. On the following day they completed a visuo-tactile affective perspective-taking paradigm measuring both self-other distinction and emotional self-salience, and a shape matching paradigm measuring perceptual self-salience. Results indicate no significant or consistent impact of training on self-other distinction performance, but reveal an increased emotional and perceptual self-salience following training to inhibit imitative tendencies. Together, these findings raise the question whether socio-cognitive training improves performance via enhanced self-other distinction, and invite to consider self-salience as a complementary angle to explain the past, present, and future findings on self-other distinction.

Interplay of self-other distinction and cognitive control mechanisms in a social automatic imitation task: An ERP study.

The regulation of motor resonance processes in daily life is indispensable. The automatic imitation task is an experimental model of those daily-life motor resonance processes. Recent research suggests that both self-other distinction and cognitive control processes may be involved in interference control during automatic imitation. Yet, we lack a clear understanding of the chronological sequence of interacting processes. To this end, this study used event-related potentials (ERPs) to investigate the time course underlying interference control during automatic imitation. We moreover aimed to extend previous results by investigating its modulation by social context. Cognitive conflict/action monitoring was assessed with the N2, in an exploratory manner the N450, and the CRN components. The Pre-Motor Positivity (PMP), associated with movement initiation, was suggested as a possible correlate of the successful resolution of self-other distinction. The cognitive control/action monitoring ERP components were influenced by the social context manipulation and partly by congruency, while PMP amplitudes were only sensitive to congruency. In addition, the exploratorily investigated N450 component predicted response times on incongruent relative to congruent trials in the different social contexts. This suggested that cognitive control/action monitoring processes, reflected in the N450, are guiding behavioral outcomes. Overall, interference control may primarily be guided by processes of cognitive control/action monitoring, whilst being modulated by social context demands.

Neural Correlates of Self-other Distinction in Patients with Schizophrenia Spectrum Disorders: The Roles of Agency and Hand Identity.

Schizophrenia spectrum disorders (SSD) are characterized by disturbed self-other distinction. While previous studies associate abnormalities in the sense of agency (ie, the feeling that an action and the resulting sensory consequences are produced by oneself) with disturbed processing in the angular gyrus, passive movement conditions to isolate contributions of motor predictions are lacking. Furthermore, the role of body identity (ie, visual features determining whether a seen body part belongs to oneself) in self-other distinction is unclear. In the current study, fMRI was used to assess the roles of agency and hand identity in self-other distinction. Patients with SSD and healthy controls (HC) performed active and passive hand movements (agency manipulation) while seeing their own or someone else's hand moving in accordance with their action (hand identity manipulation). Variable delays (0-417 ms) between movement and feedback had to be detected. Our results showed overall lower delay detection performances during active than passive conditions; however, these differences were reduced in patients when the own hand was displayed. On a neural level, we found that in HC, activation in the right angular gyrus was modulated by agency and hand identity. In contrast, agency and hand identity revealed no overlapping activation in patients, due to reduced effects of agency. Importantly, HC and SSD patients shared similar effects of hand identity in the angular gyrus. Our results suggest that disturbances of self-other distinction in SSD are particularly driven by agency, while self-other distinction based on hand identity might be spared.

Detached empathic experience of others’ pain in remitted states of depression – An fMRI study

BackgroundMajor depressive disorder is strongly associated with impairments and difficulties in social interactions. Deficits in empathy, a vital skill for social interactions, have been identified as a risk factor for relapse. However, research on empathy in remitted states of depression is scarce. We chose a social neuroscience approach to investigate potentially altered neural processes involved in sub-components of empathy in remitted states of depression. We expected aberrations in cognitive components of empathy, based on previous reports regarding their role as risk factors for relapse. MethodsEmploying functional magnetic resonance imaging and a pain empathy task (video clips of painful medical treatments), we compared behavioral and neural empathic responses of unmedicated remitted depressive patients (N = 32) to those of untreated acutely depressed patients (N = 29) and healthy controls (N = 35). Self-report ratings of pain evaluation and affect-sharing were obtained. ResultsCompared to controls and acutely depressed patients, remitted depressive patients reported higher pain evaluation and showed increased activity in the right temporo-parietal junction. This region, which is central to self-other distinction and which has been linked to adopting a detached perspective, also exhibited reduced connectivity to the anterior insula. Furthermore, we observed reduced activity in regions involved in emotion processing (amygdala) and perception of affective facial expressions (fusiform face area, posterior superior temporal sulcus). ConclusionsRemitted states of depression are associated with a detached empathic style in response to others’ pain, characterized by increased self-other distinction, lowered affective processing, and reduced connectivity between empathy-related brain regions. Although this may prevent emotional harm in specific situations, it may reduce opportunities for positive experiences in social interactions in the long run.

Prosthesis embodiment and attenuation of prosthetic touch in upper limb amputees - A proof-of-concept study.

Sensory attenuation of self-touch, that is, the perceptual reduction of self-generated tactile stimuli, is considered a neurocognitive basis for self-other distinction. However, whether this effect can also be found in upper limb amputees using a prosthesis is unknown. Thirteen participants were asked to touch their foot sole with a) their intact hand (self-touch), b) their prosthesis (prosthesis-touch), or c) let it be touched by another person (other-touch). Intensity of touch was assessed with a questionnaire. In addition, prosthesis embodiment was assessed in nine participants. Self-touch as well as prosthesis-touch was characterized by significant perceptual attenuation compared to other-touch, while self- and prosthesis-touch did not differ. The more embodied the prosthesis was, the more similar was its elicited touch perception to actual self-touch. These findings - although preliminary - suggest that perceptually embodied prostheses can be represented as an actual limb by the users' sensorimotor system.

Oxytocin weakens self-other distinction in males during empathic responses to sadness: an event-related potentials study.

By making use of event-related potential (ERP) technology, a randomized, double-blind, between-subject design study was performed in order to investigate whether OXT can weaken men’s self-other distinction during empathic responses to sad expressions. In the two experimental tasks, 39 male subjects were asked to either evaluate the emotional state shown in a facial stimulus (other-task) or to evaluate their own emotional responses (self-task). The results revealed that OXT reduced the differences in P2 (150–200 ms) amplitudes between sad and neutral expressions in the self-task but enhanced P2 to sad expressions in the other-task, indicating OXT’s role in integrating the self with others instead of separating them. In addition, OXT also reduced the LPC (400–600 ms) amplitudes between sad-neutral expressions in the self-task, implying that OXT’s weakening effects on the self-other distinction could occur at both the early and late cognitive control stages of the empathic response.

人际互动中的“自我-他人”区分:多水平的探索

人际互动中的“自我-他人”区分:多水平的探索

When Implicit Prosociality Trumps Selfishness: The Neural Valuation System Underpins More Optimal Choices When Learning to Avoid Harm to Others Than to Oneself.

Humans learn quickly which actions cause them harm. As social beings, we also need to learn to avoid actions that hurt others. It is currently unknown whether humans are as good at learning to avoid others' harm (prosocial learning) as they are at learning to avoid self-harm (self-relevant learning). Moreover, it remains unclear how the neural mechanisms of prosocial learning differ from those of self-relevant learning. In this fMRI study, 96 male human participants learned to avoid painful stimuli either for themselves or for another individual. We found that participants performed more optimally when learning for the other than for themselves. Computational modeling revealed that this could be explained by an increased sensitivity to subjective values of choice alternatives during prosocial learning. Increased value sensitivity was further associated with empathic traits. On the neural level, higher value sensitivity during prosocial learning was associated with stronger engagement of the ventromedial PFC during valuation. Moreover, the ventromedial PFC exhibited higher connectivity with the right temporoparietal junction during prosocial, compared with self-relevant, choices. Our results suggest that humans are particularly adept at learning to protect others from harm. This ability appears implemented by neural mechanisms overlapping with those supporting self-relevant learning, but with the additional recruitment of structures associated to the social brain. Our findings contrast with recent proposals that humans are egocentrically biased when learning to obtain monetary rewards for self or others. Prosocial tendencies may thus trump egocentric biases in learning when another person's physical integrity is at stake.SIGNIFICANCE STATEMENT We quickly learn to avoid actions that cause us harm. As "social animals," we also need to learn and consider the harmful consequences our actions might have for others. Here, we investigated how learning to protect others from pain (prosocial learning) differs from learning to protect oneself (self-relevant learning). We found that human participants performed better during prosocial learning than during self-relevant learning, as they were more sensitive toward the information they collected when making choices for the other. Prosocial learning recruited similar brain areas as self-relevant learning, but additionally involved parts of the "social brain" that underpin perspective-taking and self-other distinction. Our findings suggest that people show an inherent tendency toward "intuitive" prosociality.

Effect of intranasal oxytocin administration on self-other distinction: Modulations by psychological distance and gender

Preliminary evidence indicates that intranasal oxytocin (OT) administration modulates one’s ability to distinguish oneself from others (i.e., self-other distinction). However, previous findings on this topic are contradictory. The current study addressed this issue by (i) using a novel perceptual matching task examining self-other distinction compared to both close and distant others, and (ii) tentatively exploring potential modulations by gender. In a double-blind, placebo-controlled, randomized OT administration study, 100 participants (50 males and 50 females) were randomized to receive intranasal spray of 24 IU OT or placebo (PL). Afterwards, participants completed a geometry perceptual matching task in which different shapes were paired to the self, a friend, or a stranger. Participants were then asked to judge whether each pair of shapes and labels was correctly matched. The results revealed that compared to PL administration, OT facilitated distinction between the self and a friend in males but not in females. These findings provide insights for debates on the role of OT in self-other distinction by revealing modulations by psychological distance and gender, which have implications for the potential clinical applications of OT.

Empathic disequilibrium in two different measures of empathy predicts autism traits in neurotypical population

BackgroundFeatures of autism spectrum conditions (ASC) are normally distributed within the population, giving rise to the notion of the autism spectrum. One of the hallmark features of ASC is difficulties in social communication, which relies heavily on our ability to empathize with others. Empathy comprises of both cognitive (CE) and emotional (EE) components that, together, allow us to understand another’s emotions and be affected by them appropriately, while maintaining a self-other distinction. Although CE and EE depend on distinct neural and developmental trajectories, it was suggested that the two empathic capacities can influence, balance, and regulate each other. Previous findings regarding the role of emotional and cognitive empathy in ASC have been mixed. Therefore, our study aimed to investigate whether the intra-personal empathy imbalance between the cognitive and emotional components, a measure we termed empathic disequilibrium (ED), can be associated with autism traits at the neurotypical range.MethodsParticipants were 671 young-adults at the neurotypical range who self-reported their empathy, assessed using two highly validated questionnaires—the Interpersonal Reactivity Index and the Empathy Quotient, autism traits using the Autism-Spectrum Quotient, and the related traits, alexithymia, and systemizing.ResultsControlling for the total empathy score, greater ED was found to be positively correlated with autism traits. Specifically, autism traits were found to be elevated in groups of individuals with relatively higher EE than CE, underscoring their imbalance.ConclusionsOur study offers a novel perspective on the understanding of the social difficulties associated with autism tendencies in the general population and has potentially important clinical implications for understanding of ASC. We also propose a novel characterization of autism tendencies based on the imbalance between EE and CE, which we term ED, as opposed to examining EE and CE separately.

T142. SELF-OTHER DISTINCTION IN SCHIZOPHRENIA: ABNORMALITIES IN THE PREDICTION OF THE SENSORY CONSEQUENCES OF ONE’S OWN ACTIONS

BackgroundCore symptoms of schizophrenia include disturbances in the distinction between the self and the external world. It has been suggested that self-other distinction is governed by predictive processing: Copies of an action’s motor command are used to generate forward models that predict upcoming sensory input. These predictions are compared with actual sensory input, thereby enabling the brain to discard the processing of sensory input arising from one’s own actions. This is reflected in a decreased perception of and reduced BOLD signal for actively versus passively generated sensory input (suppression effect). Here, we investigated whether BOLD suppression effects for the processing of action feedback involving active and passive hand movements differ between patients with schizophrenia and healthy control participants. Since the identity of one’s body also contributes to self-other distinction, we additionally investigated if differences in BOLD suppression effects between patients and healthy controls are further modulated by whether participants see their own or someone else’s hand moving in accordance with their action.Methods17 patients with schizophrenia spectrum disorders and 13 healthy controls (matched for age, sex, and educational degree) performed active and passive hand movements while lying in the MRI scanner. During movement execution (active and passive), participants saw either a real-time video of their current movement (“self”) or someone else’s hand moving in accordance with their action (“other”). This manipulation allowed disentangling the effects of movement characteristics (e.g., who is triggering the movement) from visual identity characteristics (whose hand is moving), which both contribute to self-other distinction. Variable delays were inserted between the movement and the images (“self” and “other”), which had to be detected by the participants.ResultsPreliminary results of behavioral performance showed an interaction between group (patients vs. healthy controls) and action execution (active vs. passive): Healthy controls detected less delays in the active condition than in the passive condition, whereas this difference was reduced in patients. In line with this, active vs. passive trials revealed larger BOLD suppression effects in healthy controls than in patients with schizophrenia in multiple brain areas (e.g., lingual gyrus, middle and superior occipital gyrus, posterior parietal cortex, cerebellum). Finally, an interaction effect was found in the thalamus, such that in healthy controls, but not in patients with schizophrenia, this area showed a BOLD suppression effect for active vs. passive movements specific for feedback of one’s own hand.DiscussionWeaker behavioral and neural suppression effects in patients with schizophrenia (compared to healthy controls) show that actively generated sensory input is not as effectively discarded from further processing, suggesting that efference copy-based predictive mechanisms are impaired in patients with schizophrenia. Furthermore, BOLD suppression in the thalamus was not modulated by hand identity in patients with schizophrenia, indicating that predictive processing in schizophrenia might not take the identity of the seen body part into account.

When differences matter: rTMS/fMRI reveals how differences in dispositional empathy translate to distinct neural underpinnings of self-other distinction in empathy

Self-other distinction is crucial for empathy, since it prevents the confusion of self-experienced emotions with those of others. We aimed to extend our understanding of the neurocognitive mechanisms of self-other distinction. Thirty-one female participants underwent continuous theta burst transcranial magnetic stimulation (cTBS) targeting the right supramarginal gyrus (rSMG), a sub-region of the temporoparietal junction previously shown to be involved in self-other distinction, and the vertex, a cortical control site. Right after stimulation they completed a visuo-tactile empathy task in an MRI scanner. Self-other distinction was assessed by differences in emotion judgments, and brain activity between conditions differing in the requirement for self-other distinction. Effects of brain stimulation on self-other distinction depended on individual differences in dispositional empathic understanding: cTBS of rSMG, compared to vertex, enhanced self-other distinction in participants with lower dispositional empathic understanding, but diminished it in participants with higher empathic understanding. On the neural level, this inverse relationship between empathic disposition and self-other distinction performance was linked to a reduction of cTBS-induced rSMG activity in persons with lower dispositional empathy, and an increase in those with higher dispositional empathy. These two opposite impacts of cTBS were associated with two anatomically and functionally distinct networks. These findings open up novel perspectives on the causal role of rSMG in self-other distinction and empathy. They also suggest that considering individual differences may yield novel insights into how brain stimulation affects higher-level affect and cognition, and its neural correlates.

Prerequisites for an Artificial Self.

Traditionally investigated in philosophy, body ownership and agency—two main components of the minimal self—have recently gained attention from other disciplines, such as brain, cognitive and behavioral sciences, and even robotics and artificial intelligence. In robotics, intuitive human interaction in natural and dynamic environments becomes more and more important, and requires skills such as self-other distinction and an understanding of agency effects. In a previous review article, we investigated studies on mechanisms for the development of motor and cognitive skills in robots (Schillaci et al., 2016). In this review article, we argue that these mechanisms also build the foundation for an understanding of an artificial self. In particular, we look at developmental processes of the minimal self in biological systems, transfer principles of those to the development of an artificial self, and suggest metrics for agency and body ownership in an artificial self.

Childhood Abuse and Adult Sociocognitive Skills: Distinguishing Between Self and Other Following Early Trauma.

Experience of childhood abuse (CA) impairs complex social functioning in children; however, much less is known about its effects on basic sociocognitive processes and even fewer studies have investigated these in adult survivors. Using two behavioral tasks, this study investigated spontaneous theory of mind (ToM) and imitative behavior in 41 women with CA and 26 unaffected comparison (UC) women. In the spontaneous ToM task, UCs showed a larger ToM index than CAs, indicating more facilitation by knowledge of another's false belief. In the imitation-inhibition task, CAs experienced less interference than UCs when observing another's incongruent movements. After controlling for depression, differences in ToM became marginally significant, yet remained highly significant for inhibiting imitative behavior. The findings suggest CA survivors have altered perspective-taking and are less influenced by others' perspectives, potentially due to changes in self-other distinction. Clinical implications regarding therapeutic practice with survivors of CA are discussed.

Early interpersonal trauma reduces temporoparietal junction activity during spontaneous mentalising.

Experience of interpersonal trauma and violence alters self-other distinction and mentalising abilities (also known as theory of mind, or ToM), yet little is known about their neural correlates. This fMRI study assessed temporoparietal junction (TPJ) activation, an area strongly implicated in interpersonal processing, during spontaneous mentalising in 35 adult women with histories of childhood physical, sexual, and/or emotional abuse (childhood abuse; CA) and 31 women without such experiences (unaffected comparisons; UC). Participants watched movies during which an agent formed true or false beliefs about the location of a ball, while participants always knew the true location of the ball. As hypothesised, right TPJ activation was greater for UCs compared to CAs for false vs true belief conditions. In addition, CAs showed increased functional connectivity relative to UCs between the rTPJ and dorsomedial prefrontal cortex. Finally, the agent’s belief about the presence of the ball influenced participants’ responses (ToM index), but without group differences. These findings highlight that experiencing early interpersonal trauma can alter brain areas involved in the neural processing of ToM and perspective-taking during adulthood.

Disturbance of Ego-Boundary Enaction in Schizophrenia

The psychopathology of schizophrenic conditions is today often characterized merely in diverse and disjunctive symptomatic terms. Classically, however, what was understood to underpin and unify such diverse symptoms was a disturbance to the 'self' or 'ego,' especially in that ego's boundaries. As psychoanalytic and phenomenological theories have become less influential in psychiatry, concepts like 'self' or 'ego,' 'self-other distinction' or 'ego boundary,' have become less popular as psychopathological organizers, with the result that the very idea of distinctively 'schizophrenic' conditions has itself also appeared to want for validity. Yet within the philosophy of psychology, enactivism provides a new naturalistic framework for understanding the emergence and maintenance of the self-other distinction. This framework considers the distinction neither as something constituted a priori, nor as something showing up within experience, but rather as a continuously enacted achievement. The contention of this article is that an enactivist perspective provides us with the apparatus to retheorize the conception of ego boundaries, contribute to the reunification of the 'schizophrenia' concept, and inform the provision of therapies targeted at the schizophrenic diathesis itself.

Distinguishing Oneself From Others: Spontaneous Perspective-Taking in First-Episode Schizophrenia and its relation to Mentalizing and Psychotic Symptoms

Abstract Characteristic symptoms of schizophrenia, such as thought broadcasting, verbal hallucinations, and delusions of being controlled, suggest a failure in distinguishing between oneself and others. In addition, patients frequently experience mentalizing deficits, which could be related to such a failure. Here we investigated the tendency to distinguish self and other with a visual perspective-taking task that measures to what extent individuals spontaneously take another’s perspective when having to process their own (altercentric intrusion) or vice versa (egocentric intrusion). This was done in 22 patients with first-episode schizophrenia and 23 matched healthy controls. We assessed whether patients displayed altered altercentric or egocentric intrusion and whether such alterations are related to mentalizing deficits—as measured with the Animated Triangles Task (ATT) and The Awareness of Social Inference Task (TASIT) —and/or specific psychotic symptoms, suggestive of problems with self-other distinction. The results showed that patients display similar egocentric intrusion and increased altercentric intrusion compared to controls. Degree of altercentric intrusion was associated with severity of delusions and hallucinations that have been tied to problems with self-other distinction but not with unrelated delusions and hallucinations or negative symptom severity. Higher altercentric intrusion was also associated with better TASIT performance in both patients and controls; suggesting that it may also be beneficial. In conclusion, patients display difficulties inhibiting representations of the other when having to process self-relevant information. A failure to control or distinguish the 2 representations could give rise to the experience that others have access to and control of your thoughts and actions.

Sharpened self-other distinction in attention deficit hyperactivity disorder

IntroductionDifferentiation between self-produced tactile stimuli and touch by others is necessary for social interactions and for a coherent concept of “self”. In attention-deficit-hyperactivity-disorder (ADHD), tactile hypersensitivity and social cognition problems are part of the symptomatology, but pathophysiological mechanisms are largely unknown. Differentiation of self- and non-self- generated sensations might be key to understand and develop novel strategies for managing hypersensitivity. Here, we compared the neural signatures of affective self- and other-touch between adults with ADHD and neurotypical controls (NC). MethodsTwenty-eight adult ADHD participants and 30 age- and gender-matched NC performed a self-other-touch-task during functional magnetic resonance imaging: they stroked their own arm, an object, or were stroked by the experimenter. In addition, tactile detection thresholds and rubber hand illusion (RHI) were measured. ResultsADHD participants had more autistic traits than NC and reported to engage less in interpersonal touch. They also reported to be more sensitive to tactile stimuli. Compared to NC, ADHD participants showed enhanced responses to both the self- and other-touch conditions: stronger deactivation during self-touch in the anterior and posterior insula, and increased activation during other-touch in primary somatosensory cortex. ADHD participants had intact tactile detection thresholds, but were less susceptible to the RHI. ConclusionsUnaltered detection thresholds suggest that peripheral processing is intact, and that hypersensitivity might be driven by central mechanisms. This has clinical implications for managing somatosensory hypersensitivity in ADHD. The more pronounced differentiation between self- and other-touch might indicate a clearer self-other-distinction. This is of interest regarding body ownership perception in both NC and ADHD, and possibly other psychiatric conditions with altered self-experiences, like schizophrenia. A sharper boundary of the own body might relate to deficits in social cognition and tactile hypersensitivity.

Right-hemispheric Dominance in Self-body Recognition is Altered in Left-handed Individuals

Visual self-face and proprioceptive postural recognition predominantly activate the right inferior frontoparietal cortices in human right-handers at the population level. In the present study, prompted by the finding that left-handedness may alter lateralized cortical organization for language, sensory-motor, and cognitive functions observed in right-handers, we investigated individual variations in right-dominant use of the cortices in 50 right-handers and 50 left-handers during self-body recognition (self-face and proprioceptive) tasks. We also investigated possible between-tasks differences in this right-dominant use, and possible atypical left–right reversed lateralization (right-dominance for language and left-dominance for self-body recognition) in left-handers. We measured brain activity using functional magnetic resonance imaging while participants performed a proprioceptive postural recognition task (experiencing illusory movements of the left and the right hands), a visual self-face recognition (self-other distinction) task, and a language (verb generation) task. To evaluate hemispheric dominance, we computed individual lateralization indices for the inferior frontoparietal activities in these tasks. Left-handedness altered the right-hemispheric dominance that was observed in the majority of right-handed participants in both self-body recognition tasks. In the left-handed group, during proprioceptive recognition, participants with right-lateralization, bilaterality, or left-lateralization were equally distributed, and during self-face recognition, right-lateralization was still observed, though the number of participants who demonstrated left-lateralization increased. Atypical left–right reversed lateralization was only observed in left-handed participants, but during both self-body recognition tasks. The present study provides novel and valuable knowledge about right-hemispheric dominance in self-body recognition affected by left-handedness. We discuss how functional lateralization of self-body recognition is shaped in human brain, in terms of handedness, language lateralization, and development.