Padoa-Schioppa Camillo
Department of Neurobiology, Harvard Medical School, Boston, MA 02115, U SA.
Ann N Y Acad Sci. 2007 Dec;1121:232-53. doi: 10.1196/annals.1401.011. Epub 2007 Aug 14.
Economic choice is the behavior observed when individuals select one of many available options solely based on subjective preferences. Behavioral evidence suggests that economic choice entails two mental processes: values are first assigned to the available options, and a decision is subsequently made between these values. Numerous reports show that lesions to the orbitofrontal cortex (OFC) lead to choice deficits in various domains, and imaging studies indicate that the OFC activates when people make choices. In this chapter, we review evidence from single cell recordings linking the OFC more specifically to valuation. Individual neurons in the OFC encode the value that monkeys assign to different beverages when they choose between them. These neurons encode economic value as a subjective quantity. Most importantly, neurons in the OFC encode economic value per se, not as a modulation of sensory or motor processes. This trait distinguishes the value representation in the OFC from that observed in other brain areas. That OFC neurons encode economic value independently of visuomotor contingencies suggests that economic choice is fundamentally a choice between goods (good-based model) rather than a choice between actions (action-based model).
经济选择是指个体仅基于主观偏好从众多可用选项中选择其一的行为表现。行为学证据表明，经济选择涉及两个心理过程：首先为可用选项赋予价值，随后在这些价值之间做出决策。大量报告显示，眶额皮质（OFC）受损会导致在各个领域出现选择缺陷，而影像学研究表明，人们做出选择时OFC会被激活。在本章中，我们回顾单细胞记录的证据，这些证据更具体地将OFC与估值联系起来。当猴子在不同饮料之间进行选择时，OFC中的单个神经元会编码猴子赋予这些饮料的价值。这些神经元将经济价值编码为主观量。最重要的是，OFC中的神经元本身编码经济价值，而不是作为感觉或运动过程的调节。这一特性将OFC中的价值表征与其他脑区的表征区分开来。OFC神经元独立于视觉运动偶发事件编码经济价值，这表明经济选择从根本上说是商品之间的选择（基于商品的模型），而不是行动之间的选择（基于行动的模型）。
