Dissociation of reward and effort sensitivity in methcathinone-induced Parkinsonism
Chong TTJ., Bonnelle V., Veromann KR., Juurmaa J., Taba P., Plant O., Husain M.
© 2017 The British Psychological Society. Methcathinone-induced Parkinsonism is a recently described extrapyramidal syndrome characterized by globus pallidus and substantia nigra lesions, which provides a unique model of basal ganglia dysfunction. We assessed motivated behaviour in this condition using a novel cost-benefit decision-making task, in which participants decided whether it was worth investing effort for reward. Patients showed a dissociation between reward and effort sensitivity, such that pallidonigral complex dysfunction caused them to become less sensitive to rewards, while normal sensitivity to effort costs was maintained.