The effects of reward and punishment contingencies on decision-making in multiple sclerosis

Abstract

Many patients with multiple sclerosis (MS) show cognitive and emotional disorders. The purpose of this study is to evaluate the role of contingency learning in decision-making in young, non-depressed, highly functioning patients with MS (n 5 21) and in matched healthy controls (n 5 30). Executive functions, attention, short-term memory, speed of information processing, and selection and retrieval of linguistic material were also investigated. Contingency learning based on the cumulative effect of reward and punishment was assessed using the Iowa Gambling Test (IGT). In the classic ABCD version of the IGT, advantageous decks are characterized by immediate small reward but even smaller future punishment. In the modified EFGH version, advantageous decks are characterized by immediate large punishment but even larger future reward. Results revealed that patients with MS showed significant dysfunctions in both versions of the IGT. Performances on neuropsychological tests sensitive to dorsolateral prefrontal functions did not predict and did not correlate with the IGT scores. These results suggest that patients with MS show impaired performances on tasks designed to assess decision-making in a situation requiring the evaluation of long-term outcomes regardless of gain or loss, and that this deficit is not a pure consequence of

Preserved decision making ability in early multiple sclerosis

“…Our main finding is that, in such an early MS population, the ability to learn to avoid disadvantageous decks in the IGT does not differ from that of controls and that, in contrast to more advanced MS [22], decision making seems to be preserved in the early stages of the disease. Our results differ from those of Nagy et al [30] who found impaired decision making in MS patients with mild disability. For each boxplot, the middle horizontal line is the median, the bottom and top represent quartiles 1 and 3, the upper and lower bars mark the last observation at a distance of less than 1.5 times the interquartile range from the edge of the box, and the diamonds represent all observations that are outside the bars However, they tested a slightly more advanced MS population (all their patients already had definite MS and disease duration was one year longer on average) and the presence of IGT difficulties in their study group might be related to the evolution of the MS process.…”

“…According to Maia & McLelland [26], consciously accessible knowledge may induce overt behavior and verbal reports, which influence directly decision making; the use of non-conscious somatic markers may not be necessary in that context. For Nagy et al [30], poor decision making was rather the consequence of an impaired learning process across trials and of a greater sensitivity to recent outcomes, independently of gains or losses. Finally, we have previously suggested an impairment of emotional experience instead of cognitive changes as an inducing mechanism [22].…”

“…For each boxplot, the middle horizontal line is the median, the bottom and top represent quartiles 1 and 3, the upper and lower bars mark the last observation at a distance of less than 1.5 times the interquartile range from the edge of the box, and the diamonds represent all observations that are outside the bars However, they tested a slightly more advanced MS population (all their patients already had definite MS and disease duration was one year longer on average) and the presence of IGT difficulties in their study group might be related to the evolution of the MS process. Indeed, Nagy et al [30] hypothesized that decision making difficulties at an early stage of MS may reflect sub-clinical pathology. The observation that the development of a relapse within the 15 months following the test was, in some extent, related to the IGT performance after adjustment for demographic characteristics gives weight to their hypothesis.…”

“…This finding, which represented impaired use of previous outcome experiences in making appropriate new decisions, was associated with an inability to generate somatic markers of an emotional experience, as measured by the SCR. Recently, Nagy et al [30] assessed decision making using the IGT in a small group of RRMS patients with mild disability (mean Kurtzke Expanded Disability Status Scale [EDSS] 1.7) [24] and a short disease duration (mean 3.1 years). Their results confirmed our findings that MS patients show altered decision making ability, and suggested that this was the consequence of impaired learning ability and of a greater sensitivity to recent outcomes, independently of the gains or losses experienced in the IGT.…”

Progressive decline of decision-making performances during multiple sclerosis

“…Such as Nagy et al ( 2006) , we could not relate dysfunction in the IGT to executive defi cits or to general cognitive impairment. In addition, decline in IGT performances occurred independently of MS course (i.e., sustained progression in disability or relapsing rate during Table 2.…”