Objective: To investigate decision-making abilities of patients with Functional Motor Disorders (FMD) using the Iowa Gambling Task (IGT).

Background: FMD is a heterogeneous neuropsychiatric condition characterized by motor symptoms (e.g., weakness, paralysis, tremor, dystonia, gait disturbance) that cannot be explained by typical neurological diseases or other medical conditions, nevertheless authentic, causing significant discomfort and potential disability. A key hypothesis in FMD pathophysiology involves impairments in the Sense of Agency, where a mismatch between predicted and actual sensory feedback of a movement may lead to difficulties in attributing such movement to oneself; this may result from an overweighting of prior expectations, influenced by attention and emotion [1]. Consistently, FMD patients exhibit a “Jumping to Conclusions” bias, favoring prior beliefs over sensory evidence in decision-making tasks [2].

Method: 20 FMD patients and 23 healthy controls (HC) underwent the IGT and a neuropsychological assessment for anxiety, depression, alexithymia, cognitive functions, sensitivity to punishment and rewards.

Results: FMD patients scored significantly lower than HC on the IGT Overall Net Score, indicating impaired decision-making, despite no generalized cognitive deficits. They also showed higher depression and alexithymia and lower sensitivity to reward [table1]. Only sensitivity to reward was associated with IGT performance [table2] [figure1].

Conclusion: These findings confirm decision-making impairments in FMD and add that reduced reward sensitivity, rather than depression or alexithymia, was associated with poor decision-making. This suggests that FMD patients may struggle to use positive feedback to adjust behavior, which could hinder physiotherapy effectiveness. Physiotherapy for FMD aims to demonstrate patients’ ability to perform movements by “re-training” motor functions through education (i.e., addressing illness beliefs), minimizing self-focused attention, and providing visual feedback to encourage automatic, normal movements [3]. Addressing reward sensitivity through neuropsychological interventions may improve engagement in rehabilitation, ultimately supporting recovery.

Figure 1

Table 1

Table 2

References: [1] Hallett M, Aybek S, Dworetzky BA, McWhirter L, Staab JP, Stone J. Functional neurological disorder: new subtypes and shared mechanisms. Lancet Neurol. 2022 Jun;21(6):537-550. doi: 10.1016/S1474-4422(21)00422-1.
[2] Pareés I, Kassavetis P, Saifee TA, Sadnicka A, Bhatia KP, Fotopoulou A, Edwards MJ. ‘Jumping to conclusions’ bias in functional movement disorders. J Neurol Neurosurg Psychiatry. 2012 Apr;83(4):460-3. doi: 10.1136/jnnp-2011-300982.
[3] Nielsen G, Stone J, Matthews A, Brown M, Sparkes C, Farmer R, Masterton L, Duncan L, Winters A, Daniell L, Lumsden C, Carson A, David AS, Edwards M. Physiotherapy for functional motor disorders: a consensus recommendation. J Neurol Neurosurg Psychiatry. 2015 Oct;86(10):1113-9. doi: 10.1136/jnnp-2014-309255.

« Back to 2025 International Congress

MDS Abstracts - https://www.mdsabstracts.org/abstract/sensitivity-to-reward-and-decision-making-in-functional-motor-disorder-a-case-control-study/