Assessment of implicit language and theory of mind in multiple sclerosis.

Abstract

Increasing evidence suggests that social cognition, especially theory of mind (ToM), is impaired in individuals with multiple sclerosis (MS). ToM appears to be a determining factor for social functioning, but research has shown a connection between ToM and pragmatic language disorders among people with neurological or psychiatric disorders. Yet, pragmatic language remains a domain rarely referenced in MS. We investigated the effect of MS in terms of the ability for making inferences via pragmatic understanding and ToM. We included 21 individuals with MS and 21 healthy controls matched for age, education and linguistic skills who performed verbal tasks involving pragmatic language (Implicit Information Management Test, Narrative Discourse Task), ToM (Test of Social Faux Pas) and a visual task of making inferences (Visual Inferences Test). Performance was significantly lower for individuals with MS than controls in the Test of Social Faux Pas (total score), but performance in pragmatic tasks did not differ. Performance was significantly lower for MS individuals for logical inference on the Implicit Information Management Test and pragmatic inference on the Visual Inferences Test. Additionally, for the MS group, the total score on the Implicit Information Management Test was correlated with the faux pas test total score and hits. Even with lack of marked cognitive decline and disability in individuals with MS and lack of differences between groups in pragmatic tasks, the MS group showed lower performance in making inferences and interpreting implicit and social situations. This study highlights the link between pragmatic language and ToM difficulties in MS.