Social Cognition Decline in Multiple Sclerosis. Evidences from Intention Recognition

Background: Cognitive impairments, such as deficits in processing speed, visual learning, attention and working memory, are known to be present in patients with Multiple Sclerosis (PwMS) with profound effects on daily activities and quality of life. A so far little explored question is whether MS also affects social cognition and social perception, i.e., the initial stages in the processing of social information that culminates in the accurate analysis of the dispositions and intentions of other individuals.

Objectives: Here, we studied how well PwMS can distinguish between social and individual intentions based on movement information. Specifically, we asked whether by observing the initial phase of a two-stage action, observers would be able to understand whether the movement was associated with a cooperative, competitive, or individual intent. A second related question was whether discrimination performance in PwMS would depend on the state of the disease.

Methods: 14 patients with low EDSS (47.13±2.08 ys; mean EDSS=3.04), 6 with high EDSS (55.04±3.28 ys; mean EDSS=6.29), and 17 matched controls (40.28±2.34 ys) were recruited. Participants observed a model reaching towards and grasping a wooden block with the intent to cooperate with a partner (coop), compete against an opponent (comp), or perform an individual action at slow (slow) or fast speed (fast). The task was to predict as fast and accurately as possible the type of intention by pressing a key with the right or left index finger. To ensure that only advance sources of information were made available as to judge the model’s intention, videos were temporally occluded at the time the fingers contacted the object. Participants were tested in four conditions: slow vs fast; coop vs comp; comp vs fast; coop vs slow.

Results: Compared to control participants, PwMS were less accurate at discriminating intention, especially comp vs fast and coop vs slow intentions. This effect was more pronounced for high EDSS.

Conclusions: Results suggest that intention-from-movement recognition is deficient in PwMS. Progressing with the MS course, this deficit may contribute to explain the deterioration in interpersonal relationships experienced by PwMs over time.