Beyond the simplicity of theory of mind deficit in multiple sclerosis: from kinetic perception to socio-emotional abstraction and mentalizing.

Abstract

Theory of Mind (ToM) processing in Multiple Sclerosis (MS) is still poorly understood due to the difficulty of most tasks in qualifying the mentalizing deficit net of cognitive load. In this study, we administered the New False Belief Animation Task (NFBAT) to 50 MS and 33 healthy controls (HC) to investigate spontaneous mentalizing in ToM and goal-directed interactions. The global cognitive level was assessed by the Montreal Cognitive Assessment (MoCA). NFBAT appropriateness and intentionality scores were computed to investigate the ToM accuracy and intentionality attribution difficulties. NFBAT answers were qualitatively analyzed and categorized into kinetically and socially coherent/not coherent responses to test a low-level perceptual deficit. The main result showed dysfunctional mentalizing reasoning in MS compared to HC in the NFBAT Intentionality score in ToM conditions (p=0.028, d=0.501), while the two groups were equally proficient in mentalization accuracy. The Intentionality underperformance in MS was related to social low-level perceptual processing (β =0.06, p<0.001) and visuospatial functions (β =0.05, p =0.002). A predictive role of memory and executive functions on NFBAT Intentionality scores was not observed. These results strengthen the hypothesis that ToM in MS is likely related to low-level social processing.