Etzel Joset A, Cole Michael W, Zacks Jeffrey M, Kay Kendrick N, Braver Todd S
Washington University in St Louis, St Louis, MO, USA.
Washington University in St Louis, St Louis, MO, USA Rutgers University, Newark, NJ, USA.
Cereb Cortex. 2016 Apr;26(4):1647-59. doi: 10.1093/cercor/bhu327. Epub 2015 Jan 19.
Reward motivation often enhances task performance, but the neural mechanisms underlying such cognitive enhancement remain unclear. Here, we used a multivariate pattern analysis (MVPA) approach to test the hypothesis that motivation-related enhancement of cognitive control results from improved encoding and representation of task set information. Participants underwent two fMRI sessions of cued task switching, the first under baseline conditions, and the second with randomly intermixed reward incentive and no-incentive trials. Information about the upcoming task could be successfully decoded from cue-related activation patterns in a set of frontoparietal regions typically associated with task control. More critically, MVPA classifiers trained on the baseline session had significantly higher decoding accuracy on incentive than non-incentive trials, with decoding improvement mediating reward-related enhancement of behavioral performance. These results strongly support the hypothesis that reward motivation enhances cognitive control, by improving the discriminability of task-relevant information coded and maintained in frontoparietal brain regions.
奖励动机通常会提高任务表现，但这种认知增强背后的神经机制仍不清楚。在这里，我们使用多变量模式分析（MVPA）方法来检验这一假设，即与动机相关的认知控制增强源于任务集信息编码和表征的改善。参与者进行了两次线索提示任务切换的功能磁共振成像（fMRI）实验，第一次在基线条件下进行，第二次实验中奖励激励和无激励试验随机混合。即将执行的任务信息可以从一组通常与任务控制相关的额顶叶区域中与线索相关的激活模式中成功解码。更关键的是，在基线实验中训练的MVPA分类器在奖励试验中的解码准确率显著高于无奖励试验，解码能力的提高介导了奖励相关的行为表现增强。这些结果有力地支持了这一假设，即奖励动机通过提高额顶叶脑区编码和维持的任务相关信息的可辨别性来增强认知控制。
