Wilkinson Leonora, Tai Yen Foung, Lin Chia Shu, Lagnado David Albert, Brooks David James, Piccini Paola, Jahanshahi Marjan
Cognitive Motor Neuroscience Group, Sobell Department of Motor Neuroscience and Movement Disorders, Institute of Neurology, University College London, London, United Kingdom.
Hum Brain Mapp. 2014 Oct;35(10):5106-15. doi: 10.1002/hbm.22536. Epub 2014 Apr 28.
The basal ganglia (BG) mediate certain types of procedural learning, such as probabilistic classification learning on the 'weather prediction task' (WPT). Patients with Parkinson's disease (PD), who have BG dysfunction, are impaired at WPT-learning, but it remains unclear what component of the WPT is important for learning to occur. We tested the hypothesis that learning through processing of corrective feedback is the essential component and is associated with release of striatal dopamine. We employed two WPT paradigms, either involving learning via processing of corrective feedback (FB) or in a paired associate manner (PA). To test the prediction that learning on the FB but not PA paradigm would be associated with dopamine release in the striatum, we used serial (11) C-raclopride (RAC) positron emission tomography (PET), to investigate striatal dopamine release during FB and PA WPT-learning in healthy individuals. Two groups, FB, (n = 7) and PA (n = 8), underwent RAC PET twice, once while performing the WPT and once during a control task. Based on a region-of-interest approach, striatal RAC-binding potentials reduced by 13-17% in the right ventral striatum when performing the FB compared to control task, indicating release of synaptic dopamine. In contrast, right ventral striatal RAC binding non-significantly increased by 9% during the PA task. While differences between the FB and PA versions of the WPT in effort and decision-making is also relevant, we conclude striatal dopamine is released during FB-based WPT-learning, implicating the striatum and its dopamine connections in mediating learning with FB.
基底神经节（BG）介导某些类型的程序性学习，例如在“天气预报任务”（WPT）中的概率分类学习。患有基底神经节功能障碍的帕金森病（PD）患者在WPT学习中存在缺陷，但尚不清楚WPT的哪个组成部分对学习的发生至关重要。我们测试了这样一种假设，即通过处理纠正性反馈进行学习是关键组成部分，并且与纹状体多巴胺的释放有关。我们采用了两种WPT范式，一种是通过处理纠正性反馈（FB）进行学习，另一种是以配对联想的方式（PA）进行学习。为了验证在FB范式而非PA范式上的学习与纹状体多巴胺释放相关的预测，我们使用了连续的（11）C-雷氯必利（RAC）正电子发射断层扫描（PET），来研究健康个体在FB和PA WPT学习过程中的纹状体多巴胺释放情况。两组，FB组（n = 7）和PA组（n = 8），进行了两次RAC PET检查，一次是在执行WPT时，一次是在执行对照任务时。基于感兴趣区域的方法，与对照任务相比，在执行FB时，右侧腹侧纹状体的纹状体RAC结合电位降低了13 - 17%，表明突触多巴胺释放。相比之下，在PA任务期间，右侧腹侧纹状体的RAC结合无显著增加，增加了9%。虽然WPT的FB和PA版本在努力程度和决策方面的差异也很重要，但我们得出结论，在基于FB的WPT学习过程中纹状体多巴胺会释放，这表明纹状体及其多巴胺连接在介导基于FB的学习中发挥作用。
