Background Self/other distinction (SOD), which refers to the ability to distinguish one’s own body, actions, and mental representations from those of others, is an essential skill for effective social interaction. A large body of clinical evidence suggests that disruptions in SOD may be key to social communication deficits in individuals with autism spectrum disorders (ASD). In particular, egocentric biases have been found in cognitive, affective, behavioural, and motor domains. However, research in this area is scarce and consists of recognition paradigms that have used only static images; these methods may be insufficient for assessing SOD, given the increasing role of embodiment in our understanding of the pathophysiology of ASD. Method A single-centre, prospective pilot study was carried out to investigate, for the first time, self-recognition and SOD in seven adolescents with ASD compared with matched, typically developing controls (TDCs) using the "Alter Ego"TM double mirror paradigm. The participants viewed a double mirror in which their own face was gradually morphed into the face of an unfamiliar other (self-to-other sequence) or vice versa (other-to-self sequence); participants were instructed to indicate at which point the morph looked more like their own face than the other’s face. Two judgement criteria were used: 1) M1: the threshold at which subjects started to recognize their own face during the other-to-self morphing sequence; 2) M2: the threshold at which subjects started to recognize the other’s face during the self-to-other morphing sequence. Results Consistent with the predictions, the results showed that the participants with ASD exhibited earlier self-recognition in the other-to-self sequence and delayed other-recognition in the self-to-other sequence, suggesting an egocentric bias. SOD impairments were also marginally correlated with ASD severity, indicating earlier face recognition in more severely affected individuals. Furthermore, in contrast with that of TDCs, the critical threshold for switching between self and other varied with the direction of morphing in ASD participants. Finally, these differences in face recognition and SOD using mirrors, unlike previous research using static images, support the central place of bodily self-consciousness in SOD impairments. Conclusions Although additional research is needed to replicate the results of this preliminary study, it revealed the first behavioural evidence of altered SOD in ASD individuals on an embodied, semiecological face-recognition paradigm. Implications for understanding ASD are discussed from a developmental perspective, and new research and therapeutic perspectives are presented.

Background: The sympathy-empathy (SE) system is commonly considered a key faculty implied in prosocial behaviors, and SE deficits (also called callous-unemotional traits, CUTs) are associated with nonprosocial and even violent behaviors. Thus, the first intuitive considerations considered a lack of SE among young people who undergo radicalization. Yet, their identification with a cause, their underlying feelings of injustice and grievance, and the other ways in which they may help communities, suggest that they may actually have a lot of empathy, even an excess of it. As a consequence, the links between SE and radicalization remain to be specified. This critical review aims to discuss whether and how SE is associated with developmental trajectories that lead young people to radicalization. Method: We first recall the most recent findings about SE development, based on an interdisciplinary perspective informed by social neuroscience. Then, we review sociological and psychological studies that address radicalization. We will critically examine the intersections between SE and radicalization, including neuroscientific bases and anthropologic modulation of SE by social factors involved in radicalization. Results: This critical review indicates that the SE model should clearly distinguish between sympathy and empathy within the SE system. Using this model, we identified three possible trajectories in young radicalized individuals. In individuals with SE deficit, the legitimization of violence is enough to engage in radicalization. Concerning individuals with normal SE, we hypothesize two trajectories. First, based on SE inhibition/desensitization, individuals can temporarily join youths who lack empathy. Second, based on an SE dissociation, combining emotional sympathy increases for the in-group and cognitive empathy decreases toward the out-group. Conclusions: While confirming that a lack of empathy can favor radicalization, the counterintuitive hypothesis of a favorable SE development trajectory also needs to be considered to better specify the cognitive and affective aspects of this complex phenomenon.

Background: Previous studies have demonstrated that children who experience maltreatment show a more elevated risk of psychopathological disorders than children from the general population. The HPA (hypothalamic–pituitary–adrenal) axis is not mature at birth and undergoes strong social regulation during the first years of life. Consequently, early exposure to stress could modify the usual adaptative response to stress. In stressful situations, perturbations in both cortisol response and cortisol circadian rhythm have been observed. Nevertheless, studies that have evaluated the links between child abuse, dysregulation of the HPA axis, and mental disorders have shown diverse results. Because of the variety of methods employed in the different studies, no formal comparisons have been made. In this systematic review, we have brought together these results. Methods: We conducted a systematic review of studies analyzing the correlation between child abuse, mental disorders, and HPA axis activity in patients aged between 6 and 16 years. PubMed, Scopus, Cochrane, and Google Scholar were searched using relevant keywords and inclusion/exclusion criteria (from 2000 to 2020). Results: Fifteen studies from the 351 identified were included. Most patients were children in the child welfare system. Children who had experienced child abuse presented with more severe mental disorders (particularly in the dimensional measure) than children who had not been abused. HPA axis activity was assessed by measuring basal cortisol for some studies and cortisol reactivity for other studies. For children experiencing child abuse, there was a possible association between abuse and a decrease in the reactivity of the HPA axis. In addition, early life stress could be associated with lower matinal cortisol. However, the association between mental disorders and cortisol secretion in maltreated children did not seem obvious. Conclusions: This systematic review demonstrates that mental disorders are more frequent and severe in cases where child abuse has occurred. Moreover, children who experienced child abuse seem to present changes in the reactivity of the HPA axis. Nevertheless, the potential correlation between these changes in the reactivity of the HPA axis and mental disorders in this population needs to be evaluated in further studies.