Medial orbitofrontal cortex codes relative rather than absolute value of financial rewards in humans
Medial orbitofrontal cortex codes relative rather than absolute value of financial rewards in humans
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DOI：
10.1111/j.1460-9568.2008.06202.x
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发表时间：
2008-05-01
影响因子：
3.4
通讯作者：
Deakin, J. F. W.
中科院分区：
文献类型：
--
作者：
Elliott, R.;Agnew, Z.;Deakin, J. F. W.
近年来的功能成像研究证实了眶额皮层（OFC）参与了人类的奖赏加工，并提出了OFC反应是依赖于上下文的。一项在灵长类动物身上进行的开创性电生理实验教会动物将抽象的视觉刺激与不同价值的食物奖励联系起来。随后，对这些学习的抽象刺激和发射的OFC神经元的中值刺激进行了测量。OFC发射被证明依赖于相对值上下文。在这项研究中，我们开发了一个人类模拟的这种模式和扫描科目使用功能磁共振成像。该分析比较了神经元对两个表面上相同的事件的反应，这两个事件仅在前面的背景方面有所不同。内侧眶额皮层对相同的知觉刺激的反应是更大的刺激时，预测更有价值的两个奖励比当它预测的价值较低。在奖赏回路的其他组成部分，杏仁核和腹侧纹状体中观察到了额外的反应。中心的发现是一致的灵长类动物的结果，并建议OFC神经元编码相对而不是绝对的奖励值。杏仁核和纹状体参与编码奖励价值也与最近的功能成像数据一致。通过使用比许多功能成像研究更简单和更少混淆的范式，我们能够证明相对经济奖励价值本身是在扩展的奖励和决策网络的不同子区域中编码的。
Functional imaging studies in recent years have confirmed the involvement of orbitofrontal cortex (OFC) in human reward processing and have suggested that OFC responses are context-dependent. A seminal electrophysiological experiment in primates taught animals to associate abstract visual stimuli with differently valuable food rewards. Subsequently, pairs of these learned abstract stimuli were presented and firing of OFC neurons to the medium-value stimulus was measured. OFC firing was shown to depend on the relative value context. In this study, we developed a human analogue of this paradigm and scanned subjects using functional magnetic resonance imaging. The analysis compared neuronal responses to two superficially identical events, which differed only in terms of the preceding context. Medial OFC response to the same perceptual stimulus was greater when the stimulus predicted the more valuable of two rewards than when it predicted the less valuable. Additional responses were observed in other components of reward circuitry, the amygdala and ventral striatum. The central finding is consistent with the primate results and suggests that OFC neurons code relative rather than absolute reward value. Amygdala and striatal involvement in coding reward value is also consistent with recent functional imaging data. By using a simpler and less confounded paradigm than many functional imaging studies, we are able to demonstrate that relative financial reward value per se is coded in distinct subregions of an extended reward and decision-making network.