School of Psychology, Southwest University, Chongqing, China.
Brain Res. 2012 Feb 3;1436:92-100. doi: 10.1016/j.brainres.2011.12.018. Epub 2011 Dec 16.
Intertemporal choice may involve two processing stages: a valuation stage and a choice stage. Decision makers must integrate the various dimensions of an option (e.g., money, time) into a single measure of its subjective value (the valuation stage) and then choose the option that is the most valuable (the choice stage). Although previous studies have implicated that subjective values are represented by a diverse set of brain regions (e.g., vmPFC, VStr, and PCC) in intertemporal choice, it is not yet known which of these regions contain information that directly predicts subsequent choice. To address this question, we measured brain activity using functional MRI while participants performed a simple intertemporal choice task. The results found that participants' decision could be encoded by three specific brain areas (vmPFC, ACC, and PCC) even before they were required to make a choice, while the left posterior insula showed positively active in the choice stage when individuals selected the delayed rewards compared to the immediate rewards. These findings suggest that activation patterns in the vmPFC, ACC, and PCC were able to predict the subsequent choice preference; however, left posterior insula may play an important role for choice preference in the choice stage.
估值阶段和选择阶段。决策者必须将选项的各个维度（例如，金钱、时间）整合到其主观价值的单一衡量标准中（估值阶段），然后选择最有价值的选项（选择阶段）。尽管先前的研究表明，在跨期选择中，主观价值由一系列不同的脑区（例如 vmPFC、VStr 和 PCC）来表示，但目前尚不清楚这些脑区中哪一个包含可直接预测后续选择的信息。为了解决这个问题，我们使用功能磁共振成像（fMRI）测量了参与者在执行简单跨期选择任务时的大脑活动。结果发现，参与者的决策可以通过三个特定的大脑区域（vmPFC、ACC 和 PCC）进行编码，甚至在他们被要求做出选择之前，而当个体选择延迟奖励而不是即时奖励时，左侧后岛叶在选择阶段表现出积极活动。这些发现表明，vmPFC、ACC 和 PCC 的激活模式能够预测随后的选择偏好；然而，左侧后岛叶可能在选择阶段的选择偏好中起着重要作用。
