Neural mechanisms of perceptual decision-making and their link to neuropsychiatric symptoms in multiple sclerosis.

Affiliation

Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Excellence Cluster NeuroCure, Berlin 10117, Germany; Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin Center for Advanced Neuroimaging, Department of Neurology, Berlin 10117, Germany; Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Bernstein Center for Computational Neuroscience, Berlin 10117, Germany. Electronic address: [Email]

Abstract

BACKGROUND : Decision-making (DM) capabilities are impaired in multiple sclerosis (MS). A variety of researchers hypothesized that this impairment is associated with reduced quality of life (QoL) and neuropsychiatric symptoms. Studies explicitly testing this hypothesis, however, are rare, provided inconclusive results, or evaluated only a limited selection of DM domains. Consequently, we conducted the first MS study on perceptual DM (e.g. deciding whether a car will fit into a parking lot based on a visual percept) to test this assumption.
METHODS : Specifically, we used an fMRI task that measured brain activity in 30 MS patients and 19 healthy controls (HCs) while the participants repeatedly decided whether objects referenced indirectly via their written object names would fit into a shoebox to investigate neural mechanisms of perceptual DM. The objects varied in size and thus decision difficulty. From these data, we determined voxel-wise brain activity parameters reflecting (i) decision difficulty and (ii) decision speed and related them to behavioral DM performance, QoL, mild to moderate depressive symptoms, and fatigue.
RESULTS : Patients showed reduced DM performance. Activity reflecting decision difficulty in the middle temporal gyrus was negatively related to DM performance across MS patients and HCs; activity reflecting decision speed in MS patients was associated with depressive symptoms and fatigue in areas of the dorsal visual stream.
CONCLUSIONS : The study shows that the perceptual DM capacity is reduced in MS. Moreover, the link between neural mechanisms of perceptual DM and neuropsychiatric symptoms suggests that an impairment in this domain is clinically relevant.

Keywords

Multiple sclerosis,Neuropsychiatric symptoms,Perceptual decision-making,Task-based fMRI,

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