Évaluation de la cognition sociale : étude du raisonnement moral chez l’enfant neurotypique et avec lésion cérébrale focale

Every day, humans evolve in a highly complex social world in which they have to infer others’ intentions, respect social norms and exercise their judgment. Navigating this social world requires sophisticated cognitive machinery, better known under the term of « social cognition », a group of functions dedicated to processing, understanding and responding to social situations. Moral reasoning (MR) is one of the most advanced social cognitive skills of human kind and is the cornerstone of appropriate social behaviors. In the past decades, research in many academic domains has tried to clarify this construct and track its development during childhood and adolescence. Most current results suggest that mature moral abilities progress from an egocentric perspective to a more global comprehension of the social world, emerging from a sophisticated integration of cerebral, cognitive and emotional mechanisms. However, many questions are left unanswered regarding the most important period of changes in terms of MR and their vulnerabilities to cerebral insult. Anecdotal reports of poor moral decision-making and lack of judgment following frontal brain lesion have long been reported in classical neuropsychological literature. However, these observations have not, until now, been supported by quantitative data. Despite their shortcomings, these studies highlight the relevance of understanding the impact of cerebral lesions on social skills, particularly MR. Until recently, one obstacle to pursuing such research in neuropsychology on the typical and atypical development of MR has been the lack of ecological tools designed for children, and that limit cognitive confounds. The recent emergence of models of social competence applicable to neuropsychology, the mapping of the “social brain”, as well as the enthusiasm generated by the creation of innovative social cognition tools offers novel opportunities to study MR both in the context of healthy development and also following brain insult. The first thesis article presents a study using an innovative neuropsychological tool designed to evaluate everyday MR in children and adolescents, the Socio-Moral Reasoning Aptitude Level (So-Moral). Using this tool, the objective was to identify age-related changes in MR during an extended developmental period (6 to 20 years), investigate the existence of sex differences and, in parallel, explore the developmental sensitivity of the So-Moral tool. The study results demonstrate significant group differences in MR maturity between childhood (6-8 years) and preadolescence (9-11 years), as well as between early adolescence (12-14 years) and middle adolescence (15-17 years). Further, sex differences favoring girls were found across all developmental periods. These results are to be interpreted in light of cerebral development and cognitive development theories of MR. They indicate that the So-Moral has adequate developmental sensitivity and can support a model of healthy MR development, thus enabling future comparisons with clinical groups. The objective of the second article was to investigate social cognition (MR, moral decision-making and empathy) and socio-behavorial problems in children with early focal brain insult (EBI) to the frontal or temporal regions. The results demonstrate reduced socio-cognitive abilities in these children when compared to paired controls, most notably in terms of MR maturity. Links between empathy and MR were also found in children with focal EBI. Finally, results indicated that these individuals displayed more socio-behavioral problems than their peers. This thesis furthers our understanding of typical and atypical MR development and suggests that it is useful to evaluate social cognition in children with focal EBI with appropriate tools designed with an ecological approach. From a neurodevelopmental perspective, these studies suggest the presence of sensitive periods for the development of MR and support the idea that social cognition is vulnerable following focal EBI. Finally, the results contribute to knowledge of the developmental sensitivity of the So-Moral tool.

Keyphrases: Adolescence, Social cognition, Moral reasoning, Empathy, Focal brain lesion, Assessment, Childhood, Adolescence