Dept. of Experimental Psychology, Ghent University, 9000 Ghent, Belgium.
Neuroimage. 2014 Jan 1;84:639-47. doi: 10.1016/j.neuroimage.2013.09.039. Epub 2013 Sep 21.
Recently, attempts have been made to disentangle the neural underpinnings of preparatory processes related to reward and attention. Functional magnetic resonance imaging (fMRI) research showed that neural activity related to the anticipation of reward and to attentional demands invokes neural activity patterns featuring large-scale overlap, along with some differences and interactions. Due to the limited temporal resolution of fMRI, however, the temporal dynamics of these processes remain unclear. Here, we report an event-related potentials (ERP) study in which cued attentional demands and reward prospect were combined in a factorial design. Results showed that reward prediction dominated early cue processing, as well as the early and later parts of the contingent negative variation (CNV) slow-wave ERP component that has been associated with task-preparation processes. Moreover these reward-related electrophysiological effects correlated across participants with response time speeding on reward-prospect trials. In contrast, cued attentional demands affected only the later part of the CNV, with the highest amplitudes following cues predicting high-difficulty potential-reward targets, thus suggesting maximal task preparation when the task requires it and entails reward prospect. Consequently, we suggest that task-preparation processes triggered by reward can arise earlier, and potentially more directly, than strategic top-down aspects of preparation based on attentional demands.
最近，人们试图厘清与奖励和注意力相关的预备过程的神经基础。功能磁共振成像（fMRI）研究表明，与奖励预期和注意力需求相关的神经活动引发了具有大规模重叠的神经活动模式，同时也存在一些差异和相互作用。然而，由于 fMRI 的时间分辨率有限，这些过程的时间动态仍然不清楚。在这里，我们报告了一项事件相关电位（ERP）研究，其中提示注意力需求和奖励预期在因子设计中结合在一起。结果表明，奖励预测主导了早期线索处理，以及与任务准备过程相关的条件性负变（CNV）慢波 ERP 成分的早期和晚期部分。此外，这些与奖励相关的电生理效应在参与者之间具有相关性，与奖励预期试验中的反应时加速相关。相比之下，提示注意力需求仅影响 CNV 的后期部分，在预测高难度潜在奖励目标的线索之后，振幅最高，因此当任务需要时，提示注意力需求可以更早、更直接地引发与奖励相关的任务准备。因此，我们认为，由奖励引发的任务准备过程可能比基于注意力需求的策略性自上而下的准备过程更早出现，并且潜在地更直接。
