Dopamine enhances willingness to exert effort for reward in Parkinson's disease
Dopamine enhances willingness to exert effort for reward in Parkinson's disease
复制标题
DOI：
10.1016/j.cortex.2015.04.003
复制
发表时间：
2015-08-01
期刊：
影响因子：
3.6
通讯作者：
Husain, Masud
中科院分区：
文献类型：
--
作者：
Chong, Trevor T. -J.;Bonnelle, Valerie;Husain, Masud
帕金森病（PD）传统上被认为是一种运动障碍，但最近的数据表明，动机缺陷可能比以前认为的更普遍。在这里，我们问是否亚临床缺陷的激励决策是目前在PD，如果是这样，多巴胺能治疗是否改善这种缺陷。我们设计了一个新颖的范式，让参与者决定是否愿意以不同程度的力挤压手持式测力计以获得不同程度的奖励。对于每个参与者，我们估计了接受奖励的概率为50%的努力水平-努力“无差异点”。对PD患者（N = 26）在常规多巴胺能药物治疗的开启和关闭状态下进行测试，并将其表现与年龄匹配的对照组（N = 26）进行比较。根据里尔冷漠评定量表（LARS）的定义，没有参与者表现出临床冷漠。我们的数据表明，无论药物治疗状态如何，PD患者选择比对照组付出更少的努力以获得最低的回报。然而，总的来说，多巴胺对参与者的选择行为有激励作用，PD患者选择在相对于关闭多巴胺状态的ON状态下为给定的奖励投入更多的努力。重要的是，这种效应不能归因于运动易化。我们的结论是，赤字在激励决策中存在PD，即使在没有临床综合征的冷漠时，奖励低，但多巴胺的行为，以消除动机缺陷，促进分配的努力。(C)2015作者爱思唯尔有限公司出版
Parkinson's disease (PD) is traditionally conceptualised as a disorder of movement, but recent data suggest that motivational deficits may be more pervasive than previously thought. Here, we ask whether subclinical deficits in incentivised decision-making are present in PD and, if so, whether dopaminergic therapy ameliorates such deficits. We devised a novel paradigm in which participants decided whether they were willing to squeeze a hand-held dynamometer at varying levels of force for different magnitudes of reward. For each participant, we estimated the effort level at which the probability of accepting a reward was 50% - the effort 'indifference point'. Patients with PD (N = 26) were tested ON and OFF their usual dopaminergic medication, and their performance compared to those of age-matched controls (N = 26). No participant was clinically apathetic as defined by the Lille Apathy Rating Scale (LARS). Our data show that, regardless of medication status, patients with PD chose to engage less effort than controls for the lowest reward. Overall, however, dopamine had a motivating effect on participants' choice behaviour patients with PD chose to invest more effort for a given reward when they were in the ON relative to OFF dopamine state. Importantly, this effect could not be attributed to motor facilitation. We conclude that deficits in incentivised decision-making are present in PD even in the absence of a clinical syndrome of apathy when rewards are low, but that dopamine acts to eliminate motivational deficits by promoting the allocation of effort. (C) 2015 The Authors. Published by Elsevier Ltd.