Department of Experimental Psychology, University of Oxford, Oxford OX1 3UD, United Kingdom.
J Neurosci. 2011 Oct 5;31(40):14399-412. doi: 10.1523/JNEUROSCI.6456-10.2011.
Functional magnetic resonance imaging was used to measure activity in three frontal cortical areas, the lateral orbitofrontal cortex (lOFC), medial orbitofrontal cortex (mOFC)/ventromedial frontal cortex (vmPFC), and anterior cingulate cortex (ACC), when expectations about type of reward, and not just reward presence or absence, could be learned. Two groups of human subjects learned 12 stimulus-response pairings. In one group (Consistent), correct performances of a given pairing were always reinforced with a specific reward outcome, whereas in the other group (Inconsistent), correct performances were reinforced with randomly selected rewards. The mOFC/vmPFC and lOFC were not distinguished by simple differences in relative preference for positive and negative outcomes. Instead lOFC activity reflected updating of reward-related associations specific to reward type; lOFC was active whenever informative outcomes allowed updating of reward-related associations, regardless of whether the outcomes were positive or negative, and the effects were greater when consistent stimulus-outcome and response-outcome mappings were present. A psychophysiological interaction analysis demonstrated changed coupling between lOFC and brain areas for visual object representation, such as perirhinal cortex, and reward-guided learning, such as the amygdala, ventral striatum, and habenula/mediodorsal thalamus. In contrast, mOFC/vmPFC activity reflected expected values of outcomes and occurrence of positive outcomes, regardless of consistency of outcome mappings. The third frontal cortical region, the ACC, reflected the use of reward type information to guide response selection. ACC activity reflected the probability of selecting the correct response, was greater when consistent outcome mappings were present, and was related to individual differences in propensity to select the correct response.
功能性磁共振成像被用于测量三个额皮质区域的活动，外侧眶额皮质（lOFC）、内侧眶额皮质（mOFC）/腹内侧前额皮质（vmPFC）和前扣带皮质（ACC），当可以学习到关于奖励类型的期望，而不仅仅是奖励的存在或不存在时。两组人类受试者学习了 12 个刺激-反应配对。在一组（一致）中，特定配对的正确表现总是用特定的奖励结果来强化，而在另一组（不一致）中，正确表现用随机选择的奖励来强化。mOFC/vmPFC 和 lOFC 并没有简单地通过对正负结果的相对偏好来区分。相反，lOFC 的活动反映了与奖励类型相关的关联的更新；只要信息性结果允许更新与奖励相关的关联，lOFC 就会活跃，无论结果是正还是负，而且当存在一致的刺激-结果和反应-结果映射时，效果更大。一项心理生理相互作用分析表明，lOFC 与视觉物体代表的大脑区域（如旁海马皮质）和奖励引导学习的大脑区域（如杏仁核、腹侧纹状体和缰核/中脑背侧丘脑）之间的耦合发生了变化。相比之下，mOFC/vmPFC 的活动反映了结果的预期值和正结果的发生，而不管结果映射的一致性如何。第三个额皮质区域，ACC，反映了使用奖励类型信息来指导反应选择。ACC 的活动反映了选择正确反应的概率，当存在一致的结果映射时更大，并且与选择正确反应的倾向的个体差异有关。
