Social cognition in two brothers with Becker muscular dystrophy: an exploratory study revealing divergent behavioral phenotypes.

BACKGROUND AND OBJECTIVE: Only few studies investigated social cognition in Becker muscular dystrophy (BMD). However, brain dystrophin deficiency could be a neural substrate for cognitive, emotional, and neuropsychological features in BMD. METHODS: We compared interoceptive accuracy and interpersonal comfort distance in two brothers with BMD presenting with the same genetic deletion and a healthy control. When possible, we collected neuropsychological and psychopathological assessments. RESULTS: Our BMD patients were significantly different in interoceptive accuracy, with patient 1 being extremely accurate and patient 2 being significantly less accurate than his brother but more accurate than the control. Interestingly, they presented opposite patterns of interpersonal distance. Patient 1 was comfortable with very short interpersonal distance (≤50 cm from the confederate/object) vs the control and patient 2. By contrast, patient 2 preferred larger distance vs the control and patient 1. Patient 1 also presented difficulties in social and emotional skills on the psychopathological assessment. CONCLUSIONS: We are aware this is a small sample; nonetheless, this is also the first description of such aspects in BMD and the first report ever of such divergent behavioral pattern. As impaired social cognition affects the quality of life and social relationship, further studies are needed for a closer understanding of involved mechanisms.

Disorganized Communication and Social Dysfunction in Schizophrenia: Emerging Concepts and Methods.

PURPOSE OF REVIEW: In this review, we embrace the emerging field of second-person neuroscience to address disorganization in schizophrenia. We argue that the focus of interest for disorganization is the interpersonal space where shared mental processes ('social mind') occur based on the bio-behavioural synchrony between two (or more) interacting people. We lay out several bio-behavioural measures that can capture the component parts of this process. In particular, we highlight the real-time imaging technology of hyperscanning that enables multi-person analysis of naturalistic social interaction. We illustrate how these measures can be used in empirical studies by posing disorganization as a problem of interpersonal processing. RECENT FINDINGS: Traditionally, disorganized speech and behaviour have been studied as the product of hidden cognitive processes ('private mind'). A dysfunction in these processes was attributed to the brain afflicted by the illness ('brain-bound mechanisms'). But this approach has contributed to challenges in measuring and quantifying disorganization. Consequently, the single-brain focus has not provided satisfactory clarity or led to effective treatments for persistent social dysfunction in schizophrenia. Social dysfunction is a core feature of schizophrenia. This dysfunction arises from disorganized interpersonal interaction that typifies the social profile of affected individuals. We outline challenges in employing several emerging concepts and methods and how they can be addressed to investigate the mechanisms of social dysfunction in schizophrenia.

Neural Correlates of Interpersonal Space Permeability and Flexibility in Autism Spectrum Disorder.

Previous research indicates that the size of interpersonal space at which the other is perceived as intrusive (permeability) and the ability to adapt interpersonal distance based on contextual factors (flexibility) are altered in Autism Spectrum Disorder (ASD). However, the neurophysiological basis of these alterations remains poorly understood. To fill this gap, we used fMRI and assessed interpersonal space preferences of individuals with ASD before and after engaging in cooperative and non-cooperative social interactions. Compared to matched controls, ASDs showed lower comfort in response to an approaching confederate, indicating preference for larger interpersonal space in autism (altered permeability). This preference was accompanied by reduced activity in bilateral dorsal intraparietal sulcus (dIPS) and left fusiform face area (FFA), regions previously shown to be involved in interpersonal space regulation. Furthermore, we observed differences in effective connectivity among dIPS, FFA, and amygdala in ASDs compared to controls, depending on the level of experienced comfort. No differences between groups were observed in interpersonal space regulation after an experienced social interaction (flexibility). Taken together, the present findings suggest that a dysregulation of the activity and connectivity of brain areas involved in interpersonal space processing may contribute to avoidance of physical proximity and social impairments in ASD.

The effect of height and shoulder-to-hip ratio on interpersonal space in virtual environment.

Previous research has associated men's physical features such as height and Shoulder-to-Hip Ratio (SHR) with dominance. Proxemics literature has suggested that the interpersonal space (comfort distance) increases in threatening and uncomfortable situations and decreases in unthreatening and comfortable situations. In the current study, we aimed to investigate the effect of different heights and SHRs on comfortable interpersonal distance by systematic manipulation of virtual confederates bodily features. More specifically, participants determined their comfort distances from virtual male confederates with different heights and SHRs in a virtual environment. We hypothesized that a virtual confederate's height and SHR influences the perception of interpersonal dominance; and consequently interpersonal space increases for taller and broader confederates as a result of increased interpersonal dominance. Results showed that comfortable interpersonal distance was positively associated with height for male participants, but not for female participants. No effect was found for shoulder width, neither for male nor female participants. Results were discussed in terms of the importance of height as a signal of dominance and fighting ability.

Perception of Peripersonal and Interpersonal Space in Patients with Restrictive-type Anorexia.

This study examines whether the perception of peripersonal action-space and interpersonal social-space is modified in patients with restrictive-type anorexia in two experimental conditions using videos. First, participants stopped the video of an approaching stimulus when they felt the distance to be comfortable for interacting with it (first-person perspective). Second, participants stopped the video when an observed individual approaching a stimulus, or being approached by it, was at a comfortable distance (third-person perspective). In the first-person perspective, the results showed an estimation of peripersonal space that did not differ from controls when an object was approaching and an increase in interpersonal space compared with controls when a male or female individual was approaching. In the third-person perspective, both individual-object and individual-individual distances were larger in anorexic patients. These results indicate a specific deficit in adjusting interpersonal distances in both the first-person and third-person perspectives. Copyright © 2017 John Wiley & Sons, Ltd and Eating Disorders Association.

Wearing a Mask Shapes Interpersonal Space during COVID-19 Pandemic.

Social distancing norms have been promoted after the COVID-19 pandemic. In this work, we tested interpersonal space (IPS) in 107 subjects through a reaching-comfort distance estimation task. In the main experiment, subjects had to estimate the comfort and reach space between an avatar wearing or not wearing a face mask. We found that IPS was greater between avatars not wearing a mask with respect to stimuli with the mask on, while reaching space was not modulated. IPS increment in the NoMask condition with respect to the Mask condition correlated with anxiety traits, as shown with the State-Trait Anxiety Inventory, rather than with transient aspects related to the pandemic situation. In the control experiment, the avatars with a mask were removed to further explore the conditioning effect provided by the presence of the facial protection in the main experiment. We found a significant difference comparing this condition with the same condition of the main experiment, namely, the distances kept between avatars not wearing a mask in the main experiment were greater than those between the same stimuli in the control experiment. This showed a contextual adaptation of IPS when elements related to the actual pandemic situation were relevant. Additionally, no significant differences were found between the control experiment and the Mask condition of the main experiment, suggesting that participants had internalized social distancing norms and wearing a mask has become the new normal. Our results highlight the tendency of people in underestimating the risk of contagion when in the presence of someone wearing a mask.

Influence of Wearing Surgical Mask on Interpersonal Space Perception Between Mainland Chinese and Taiwanese People.

Wearing face masks and maintaining social distancing of 1.5m are two common preventive measures against the spread of COVID-19. However, the interaction of these preventive measures in interpersonal space (IPS) perception remains unknown. This study evaluated the effects of wearing surgical masks, sex dyads, and approaching patterns on IPS judgment. Data were collected from participants from Mainland China (n=100) and Taiwan (n=100) through an online survey. Therefore, the regional differences were also examined. A smaller IPS was observed when participants faced confederates wearing surgical masks than in the no-mask condition. Female dyads tended to maintain a smaller IPS than did both male and mixed-sex dyads, and Taiwanese participants maintained a significantly larger IPS than did Mainland Chinese participants. No significant difference was observed between the active and passive pattern. Moreover, the interaction between region and mask had a significant influence on IPS perception. Among all test combinations, only the IPS perceived by Taiwanese participants facing confederates without surgical masks exceeded 1.5m. This study revealed that the wearing of surgical masks for health protection during the pandemic influences IPS perception in different regions. The current findings may provide useful information for social interaction and environmental design during the COVID-19 pandemic.

Social Distance during the COVID-19 Pandemic Reflects Perceived Rather Than Actual Risk.

Interpersonal space (IPS) is the area surrounding our own bodies in which we interact comfortably with other individuals. During the COVID-19 pandemic, keeping larger IPS than usual, along with wearing a face mask, is one of the most effective measures to slow down the COVID-19 outbreak. Here, we explore the contribution of actual and perceived risk of contagion and anxiety levels in regulating our preferred social distance from other people during the first wave of the COVID-19 pandemic in Italy. In this study, 1293 individuals from six Italian regions with different levels of actual risk of infection participated in an online survey assessing their perceived risk to be infected, level of anxiety and IPS. Two tasks were adopted as measures of interpersonal distance: the Interpersonal Visual Analogue Scale and a questionnaire evaluating interpersonal distance with and without face mask. The results showed that the IPS regulation was affected by how people subjectively perceived COVID-19 risk and the related level of anxiety, not by actual objective risk. This clarifies that the role of threat in prompting avoidant behaviors expressed in increased IPS does not merely reflect environmental events but rather how they are subjectively experienced and represented.

The plasticity of the interpersonal space in autism spectrum disorder.

In recent years, there has been a dramatic increase in research examining interpersonal space, i.e., the sector of space immediately around the body in which we interact with other people. These studies have consistently revealed impairments of interpersonal space regulation in psychopathological disorders characterized by social disability, such as autism, schizophrenia and social anxiety. The primary goal of this review is to discuss several key points that have emerged in research on interpersonal space regulation in autism spectrum disorders. Particularly, we review recent behavioral evidence revealing that individuals with autism prefer abnormally larger or shorter interpersonal distance than healthy controls, indicating a deficit in regulating the size of interpersonal space (permeability). Then, we focus on how individuals with autism fail to modify their interpersonal space following a brief cooperative interaction with an unfamiliar adult, suggesting a deficit in adapting interpersonal space to the social context (plasticity). Moreover, we discuss evidence indicating that space regulation deficits primarily affect interpersonal (i.e., social), but not peripersonal (i.e., action), space in autism. Finally, we take into consideration the variables influencing interpersonal space plasticity such as person's perspective and severity of social impairment as well as its neural underpinnings. These findings may provide a critical contribution to understanding of the functional mechanisms underlying interpersonal space regulation and its rehabilitation in autism spectrum disorders.

An Investigation Into Interpersonal and Peripersonal Spaces of Chinese People for Different Directions and Genders.

This study explores the interpersonal space (IPS) and peripersonal space (PPS) of Chinese people and evaluates the relationship between the two spaces for different directions and genders. Seventy-one participants were recruited for this study. Participants were required to determine their IPS in eight directions (0°, 45°, 90°, 135°, 180°, 225°, 270°, 315°) when approached by male or female confederates in the comfort distance task. Each participant was also asked to judge their PPS in five directions (0°, 45°, 90°, 270°, 315°) following the same procedure. Results showed that their IPS was significantly influenced by direction (p < 0.05), with the largest distance in the front (0°) and the closest distance in the rear (135°, 180°, 225°), indicating non-circular IPS among Chinese subjects. Moreover, the PPS on the right side (90°) was larger than in other directions (0°, 45°, 270°, 315°). Participants maintained larger IPS than PPS in the front, but the IPS was closer than PPS on the right and left sides. When facing a female confederate, larger IPS was preferred than PPS, whereas the opposite held true when facing a male confederate. Comparison of participants' arm length and PPS showed that the reachability distance was overestimated in the front but underestimated laterally. The findings of this study can be applied to environmental design, space utilization, and social interaction.

The influence of facial expression at perceptual threshold on electrodermal activity and social comfort distance.

Interpersonal distance, an essential component of social interaction, is modulated by the emotion conveyed by others and associated physiological response. However, in modern societies with overcrowded and hyperstimulating environments, we can only surreptitiously glimpse the faces of others in order to quickly make behavioral adjustments. How this impacts social interactions is not yet well understood. In the present study, we investigated this issue by testing whether facial expressions that are difficult to identify modify the physiological response (Electrodermal Activity, EDA) and subsequent judgment of interpersonal comfort distance. We recorded participants' EDA while they provided comfort judgments to interpersonal distances with a Point-Light Walker (PLW). The PLW, with an emotionally neutral gait, moved toward and crossed participants at various distances after the latter were exposed to a negative (anger), positive (happiness) or neutral facial expression presented at the perceptual threshold. Bayesian analyses of the data revealed an increase versus decrease of interpersonal comfort distance with the PLW depending on the negative versus positive emotional valence of the facial expression. They also showed an increase in EDA when the approaching PLW violated interpersonal comfort distance after participants were exposed to an angry facial expression. These effects correlated with the subjective assessment of the arousal of facial expressions. Thus, previous exposure to barely visible facial expressions can alter the representation of social comfort space and the physiological response associated with a violation of interpersonal comfort distances, depending on the valence and arousal of the emotional social stimuli.

The illusion of having a tall or short body differently modulates interpersonal and peripersonal space.

The brain constructs a functional representation of the space around the body, the so called peripersonal space (PPS), which is a sensorimotor interface used to ensure suitable motor acts. However, this sector of space is also involved in social interactions. Individuals indeed, maintain an interpersonal space (IPS) indicating how close they prefer to stand relative to others. Here, we investigated whether a change in one's own body height representation can differently modulate action and social space. To this aim, we measured IPS and PPS in a similar way through a Reaching-distance and a Comfort-distance task, respectively, before and after participants experienced the illusion of having a tall (Experiment 1), or a short (Experiment 2), body. The illusion of having a tall body significantly reduced the IPS and enlarged PPS. On the other hand, the illusion of having a short body contracted the IPS, leaving the PPS intact. A further experiment (Experiment 3), showed that the illusory ownership for the tall or short body is a necessary condition to update the participants' height representation. Thus, a change in body height representation was effective to reveal a dissociation in the representation of the space around the body, depending on whether this sector of space is used for programming actions, or for regulating social interactions.

When social and action spaces diverge: A study in children with typical development and autism.

The space around the body has been defined as action space (peripersonal space) and a social space (interpersonal space). Within the current debate about the characteristics of these spaces, here we investigated the functional properties and plasticity of action and social space in developmental age. To these aims, children with typical development and autism spectrum disorders were submitted to Reaching- and Comfort-distance tasks, to assess peripersonal and interpersonal space, respectively. Participants approached a person (confederate) or an object and stopped when they thought they could reach the stimulus (Reaching-distance task), or they felt comfortable with stimulus' proximity (Comfort-distance task). Both tasks were performed before and after a cooperative tool-use training, in which participant and confederate actively cooperated to reach tokens by using either a long (Experiment 1) or a short (Experiment 2) tool. Results showed that in both groups, peripersonal space extended following long-tool-use but not short-tool-use training. Conversely, in typical development, but not in autism spectrum disorders children, interpersonal space toward confederate reduced following the cooperative tool-use training. These findings reveal that action and social spaces are functionally dissociable both in typical and atypical development, and that action but not social space regulation is intact in children with autism.

The role of oxytocin in implicit personal space regulation: An fMRI study.

Personal space, defined as the distance individuals choose to maintain between themselves and others, is an indicator of affiliation and closeness. Most paradigms that measure personal space preferences involve explicit choice and therefore fail to examine the implicit aspects of such preferences. In the current study, we sought to investigate an implicit form of interpersonal space that is more closely related to real-life situations involving affiliation. We studied the effects of oxytocin (OT) on neural networks that involve affiliation and tested the impact on personal space preferences. In a double-blind placebo-controlled study, we asked participants to choose between two rooms that differed only in the distances between two stimuli. The stimuli were either social stimuli (two chairs) or non-social stimuli (table and plant). The behavioral results showed that OT caused participants to choose a closer space in social blocks but did not affect their choices in non-social blocks. Imaging results revealed an interaction between stimulus and treatment (OT/PL) in the dorsal striatum, an area that is related to approach motivation and is part of the reward circuitry. Specifically, OT increased activity in the dorsal striatum in the social blocks and decreased this activity in the non-social blocks. The results of the study strengthen the social salience theory regarding OT, indicating that OT does not uniformly affect all social responses and that context has a determining impact on our behavior.

Oxytocin regulates social approach.

The physical space individuals share is known as interpersonal space. As social creatures, people tend to approach others actively and explore the environment around them, opting for different space preferences with different people. In the current study, we sought to examine the role of oxytocin (OT) in regulating active social interpersonal space preferences. Contrary to previous studies that reported a preference for increased space following intranasal OT, we predicted that following OT administration individuals would exhibit increased active approach towards a protagonist. Accordingly, we measured active approach towards friends and strangers. The results indicated that OT increased social approach, particularly to strangers, suggesting that the OT system plays a major role in regulating social approach, depending on type of protagonist. The results are in line with the social salience and anxiety reduction hypotheses showing that OT increases approach to strangers.

Physiological Response to Facial Expressions in Peripersonal Space Determines Interpersonal Distance in a Social Interaction Context.

Accurate control of interpersonal distances in social contexts is an important determinant of effective social interactions. Although comfortable interpersonal distance seems to be dependent on social factors such as the gender, age and activity of the confederates, it also seems to be modulated by the way we represent our peripersonal-action space. To test this hypothesis, the present study investigated the relation between the emotional responses registered through electrodermal activity (EDA) triggered by human-like point-light displays (PLDs) carrying different facial expressions (neutral, angry, happy) when located in the participants peripersonal or extrapersonal space, and the comfort distance with the same PLDs when approaching and crossing the participants fronto-parallel axis on the right or left side. The results show an increase of the phasic EDA for PLDs with angry facial expressions located in the peripersonal space (reachability judgment task), in comparison to the same PLDs located in the extrapersonal space, which was not observed for PLDs with neutral or happy facial expressions. The results also show an increase of the comfort distance for PLDs approaching the participants with an angry facial expression (interpersonal comfort distance judgment task), in comparison to PLDs with happy and neutral ones, which was related to the increase of the physiological response. Overall, the findings indicate that comfort social space can be predicted from the emotional reaction triggered by a confederate when located within the observer's peripersonal space. This suggests that peripersonal-action space and interpersonal-social space are similarly sensitive to the emotional valence of the confederate, which could reflect a common adaptive mechanism in specifying theses spaces to subtend interactions with both the physical and social environment, but also to ensure body protection from potential threats.

The role of oxytocin in modulating interpersonal space: A pharmacological fMRI study.

Interpersonal space is a nonverbal indicator of affiliation and closeness. In this study we investigated the effects of oxytocin (OT), a neuropeptide known for its social role in humans, on interpersonal space. In a double blind placebo controlled study we measured the effect of intranasal OT on the personal distance preferences of different familiar (friend) and unfamiliar (stranger) protagonists. Behavioral results showed that participants preferred to be closer to a friend than to a stranger. Intranasal OT was associated with an overall distancing effect, but this effect was significant for the stranger and not for the friend. The imaging results showed interactions between treatment (OT, placebo) and protagonist (friend, stranger) in regions that mediate social behavior including the dorsomedial prefrontal cortex (dmPFC), a region associated with the mentalizing system. Specifically, OT increased activity in the dmPFC when a friend approached the participants but not when a stranger approached. The results indicate that the effect of OT on interpersonal space greatly depends on the participant's relationship with the protagonist. This supports the social salience theory, according to which OT increases the salience of social cues depending on the context.

Cooperative tool-use reveals peripersonal and interpersonal spaces are dissociable.

The space surrounding people is often termed Interpersonal (IPS) in social psychology and Peripersonal (PPS) in neuroscience. In the current debate about their origin, the prevalent opinion is they share common functional characteristics. Bucking the trend, here we report a dissociation between PPS, operationalized as reachable space, and IPS, operationalized as comfort space. To probe their plasticity we introduced a novel type of cooperative long-tool-use that would modify both spaces. Results showed the estimated IPS referred to another individual was reduced, as expected following a positive social interaction. In sharp contrast, the estimated PPS toward the very same cooperative person was actually extended after use of the same long-tool. Control short-tool-use selectively reduced IPS, but not PPS, when performed in the same cooperative set or had no effect on either space estimation, when performed in a neutral set where the other person is not interacting cooperatively, but simply observing. The use of tools to perform actions in social settings allows us to report the first strong evidence that PPS and IPS underlie dissociable plastic representations: the former representation is sensitive to long-tool-dependent plasticity, whereas the latter representation, independently of use of a short or long tool, is sensitive to cooperation-dependent plasticity.

Neural Substrate of Group Mental Health: Insights from Multi-Brain Reference Frame in Functional Neuroimaging.

Contemporary mental health practice primarily centers around the neurobiological and psychological processes at the individual level. However, a more careful consideration of interpersonal and other group-level attributes (e.g., interpersonal relationship, mutual trust/hostility, interdependence, and cooperation) and a better grasp of their pathology can add a crucial dimension to our understanding of mental health problems. A few recent studies have delved into the interpersonal behavioral processes in the context of different psychiatric abnormalities. Neuroimaging can supplement these approaches by providing insight into the neurobiology of interpersonal functioning. Keeping this view in mind, we discuss a recently developed approach in functional neuroimaging that calls for a shift from a focus on neural information contained within brain space to a multi-brain framework exploring degree of similarity/dissimilarity of neural signals between multiple interacting brains. We hypothesize novel applications of quantitative neuroimaging markers like inter-subject correlation that might be able to evaluate the role of interpersonal attributes affecting an individual or a group. Empirical evidences of the usage of these markers in understanding the neurobiology of social interactions are provided to argue for their application in future mental health research.