Encodage visuel dans le raisonnement moral chez l’adulte neurotypique et ayant un trouble du spectre autistique

Moral reasoning is a cognitive process that underlies the ability to make appropriate decisions in social situations that present a moral conflict. Visual encoding is an important step in social information processing and supports the interpretation of social cues. Faces, in particular, convey a large amount of information, which can be used in the planning and production of social behaviours. Studies using eye-tracking techniques suggest that visual encoding can predict moral decision-making when individuals face extreme dilemmas, such as life and death situations. However, no study has explored visual encoding in dilemmas representative of everyday life. Moreover, Autism Spectrum Disorder (ASD) is associated with social cognition deficits, as well as some particularities in terms of the visual encoding of social information. These social features of the autistic phenotype suggest a possible impact on moral reasoning. However, some studies indicate that individuals with ASD perform similarly to neurotypical participants on moral reasoning tasks, raising the hypothesis of alternative mechanisms of moral reasoning in ASD. The objective of this thesis was to use an ecological and visual paradigm in eye-tracking to evaluate the contribution of visual encoding to moral reasoning in typically developing individuals and individuals with ASD. In the first study, neurotypical participants completed the Socio-Moral Reasoning Aptitude Level (SoMoral) task. The task presents pictures describing situations representative of everyday life moral dilemmas. Moral decision-making and the level of moral maturity of the justifications produced were documented while eye movements and pupillary dilation were recorded. While visual encoding was not a significant predictor of moral decision-making, it was a significant predictor of the level of moral maturity.  In the second study, a similar protocol was used with two groups (ASD, Controls) comparable in age, intelligence and sex. Comprehension of dilemmas, moral decision-making and moral justification were assessed using the SoMoral. Eye movements and pupillary dilation were again measured using eye-tracking. In terms of visual encoding, participants with ASD produced their first fixation on faces later than the neurotypical control group. They also understood fewer dilemmas and produced fewer socially adaptive responses. Moreover, they generally relied less on social or interpersonal justifications, and more on fundamental moral principles. Finally, visual encoding was a significant predictor of moral maturity for both groups. These studies confirm that visual encoding of social cues contributes to moral reasoning in social situations relevant to everyday life. The two studies also highlight the relevance of studying a variety of aspects of moral reasoning (understanding, decision-making, justification) for a global understanding of the phenomenon. From a clinical perspective, this thesis provides a better understanding of moral reasoning in ASD. This could help guide the development of new interventions for individuals with ASD.

Keyphrases: Moral reasoning, Moral decision-making, Visual encoding, Eye-tracking, Pupillometry, Autism spectrum disorder, social cognition