Motivational Sensitivities Linked to Impulsive Motor Errors in Parkinson's Disease

Abstract

Objectives: We investigated how broad motivational tendencies are related to the expression and suppression of action impulses in Parkinson's disease (PD). Methods: Sixty-nine participants with PD completed a Simon response conflict task and Behavioral Inhibition System (BIS) and Behavioral Activation System (BAS) scales based on Gray's (1987) reinforcement sensitivity theory. Analyses determined relationships between BIS, BAS, and the susceptibility to making impulsive action errors and the proficiency of inhibiting interference from action impulses. Results: BIS scores correlated positively with rates of impulsive action errors, indicating that participants endorsing low BIS tendencies were much more susceptible to acting on strong motor impulses. Analyses of subgroups with high versus low BIS scores confirmed this pattern and ruled out alternative explanations in terms of group differences in speed-accuracy tradeoffs. None of the scores on the BIS or BAS scales correlated with reactive inhibitory control. Conclusions: PD participants who endorse diminished predilection toward monitoring and avoiding aversive experiences (low BIS) show much greater difficulty restraining fast, impulsive motor errors. Establishing relationships between motivational sensitivities and cognitive control processes may have important implications for treatment strategies and positive health outcomes in participants with PD, particularly those at risk for falling and driving difficulties related to impulsive reactions. (JINS, 2018, 24, 128-138).