We hypothesized that during binary economic choice, decision makers use the first option they attend as a default to which they compare the second. To test this idea, we recorded activity of neurons in the dorsal anterior cingulate cortex (dACC) of macaques choosing between gambles presented asynchronously. We find that ensemble encoding of the value of the first offer includes both choice-dependent and choice-independent aspects, as if reflecting a partial decision. That is, its responses are neither entirely pre- nor post-decisional. In contrast, coding of the value of the second offer is entirely decision dependent (i.e., post-decisional). This result holds even when offer-value encodings are compared within the same time period. Additionally, we see no evidence for 2 pools of neurons linked to the 2 offers; instead, all comparison appears to occur within a single functionally homogenous pool of task-selective neurons. These observations suggest that economic choices reflect a context-dependent evaluation of attended options. Moreover, they raise the possibility that value representations reflect, to some extent, a tentative commitment to a choice.

我们假设在二元经济选择过程中，决策者将他们参加的第一个选择作为默认选择，与第二个选择进行比较。为了验证这个想法，我们记录了猕猴在异步赌博之间选择的背前扣带回皮层（dACC）中神经元的活动。我们发现，对第一个要约的价值进行整体编码既包括与选择有关的方面，也包括与选择无关的方面，就好像反映了部分决策一样。也就是说，它的响应既不是完全决定性的，也不是决定性的。相反，第二要约的价值的编码完全取决于决策（即决策后）。即使在同一时间段内比较要约值编码，此结果仍然成立。另外，我们看不到有证据表明有2个神经元池与2个提议相关。反而，所有比较似乎都发生在单个功能相同的任务选择神经元池中。这些观察结果表明，经济选择反映了对参与期权的上下文相关评估。而且，它们增加了价值表示在某种程度上反映对选择的初步承诺的可能性。