Department of Experimental Psychology, University of Oxford, Oxford OX1 3UD, United Kingdom.
Proc Natl Acad Sci U S A. 2010 Nov 23;107(47):20547-52. doi: 10.1073/pnas.1012246107. Epub 2010 Nov 8.
Uncertainty about the function of orbitofrontal cortex (OFC) in guiding decision-making may be a result of its medial (mOFC) and lateral (lOFC) divisions having distinct functions. Here we test the hypothesis that the mOFC is more concerned with reward-guided decision making, in contrast with the lOFC's role in reward-guided learning. Macaques performed three-armed bandit tasks and the effects of selective mOFC lesions were contrasted against lOFC lesions. First, we present analyses that make it possible to measure reward-credit assignment--a crucial component of reward-value learning--independently of the decisions animals make. The mOFC lesions do not lead to impairments in reward-credit assignment that are seen after lOFC lesions. Second, we examined how the reward values of choice options were compared. We present three analyses, one of which examines reward-guided decision making independently of reward-value learning. Lesions of the mOFC, but not the lOFC, disrupted reward-guided decision making. Impairments after mOFC lesions were a function of the multiple option contexts in which decisions were made. Contrary to axiomatic assumptions of decision theory, the mOFC-lesioned animals' value comparisons were no longer independent of irrelevant alternatives.
眶额皮层（OFC）在指导决策方面的功能存在不确定性，这可能是由于其内侧（mOFC）和外侧（lOFC）区域具有不同的功能。在这里，我们检验了以下假设，即 mOFC 更关注奖励引导的决策，而 lOFC 在奖励引导学习中起作用。猕猴执行了三臂赌博任务，并将选择性 mOFC 损伤的影响与 lOFC 损伤进行了对比。首先，我们进行了分析，使我们能够独立于动物做出的决策来衡量奖励信贷分配——奖励价值学习的关键组成部分。mOFC 损伤不会导致像 lOFC 损伤后那样出现的奖励信贷分配受损。其次，我们研究了选择选项的奖励价值如何进行比较。我们提出了三种分析方法，其中一种方法独立于奖励价值学习来检查奖励引导的决策。mOFC 的损伤而不是 lOFC 的损伤破坏了奖励引导的决策。mOFC 损伤后的损伤是根据决策所涉及的多个选项上下文而定的。与决策理论的公理假设相反，mOFC 损伤动物的价值比较不再与不相关的替代方案无关。
