Department of Psychology, University of Maryland, College Park, MD 20742, USA.
Neuropsychologia. 2013 Aug;51(9):1763-72. doi: 10.1016/j.neuropsychologia.2013.05.025. Epub 2013 Jun 13.
Appetitive stimuli such as monetary incentives often improve performance whereas aversive stimuli such as task-irrelevant negative stimuli frequently impair performance. But our understanding of how appetitive and aversive processes simultaneously contribute to brain and behavior is rudimentary. In the current fMRI study, we investigated interactions between reward and threat by investigating the effects of monetary reward on the processing of task-irrelevant threat stimuli during a visual discrimination task. Reward was manipulated by linking fast and accurate responses to foreground stimuli with monetary reward; threat was manipulated by pairing the background context with mild aversive shock. The behavioral results in terms of both accuracy and reaction time revealed that monetary reward eliminated the influence of threat-related stimuli. Paralleling the behavioral results, during trials involving both reward and threat, the imaging data revealed increased engagement of the ventral caudate and anterior mid-cingulate cortex, which were accompanied by increased task-relevant processing in the visual cortex. Overall, our study illustrates how the simultaneous processing of appetitive and aversive information shapes both behavior and brain responses.
奖赏刺激物,如金钱奖励,通常会提高表现,而厌恶性刺激物,如与任务不相关的负性刺激物,常常会损害表现。但我们对奖赏和厌恶过程如何同时影响大脑和行为的理解还很初步。在当前的 fMRI 研究中,我们通过研究金钱奖励对视觉辨别任务中与任务不相关的威胁性刺激处理的影响,来研究奖赏和威胁之间的相互作用。通过将快速准确的响应与前景刺激物相关联来操纵奖赏,通过将背景环境与轻度厌恶刺激配对来操纵威胁。在准确性和反应时间方面的行为结果表明,金钱奖励消除了与威胁相关刺激的影响。与行为结果平行的是,在涉及奖赏和威胁的试验中,成像数据显示腹侧尾状核和前扣带皮层的参与度增加,同时伴随着视觉皮层中与任务相关的处理增加。总的来说,我们的研究说明了如何同时处理奖赏和厌恶信息来塑造行为和大脑反应。