Behavioral and neural representation of expected reward and risk
Behavioral and neural representation of expected reward and risk
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DOI：
10.1016/j.neuroimage.2022.119731
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发表时间：
2022-11-07
期刊：
影响因子：
5.7
通讯作者：
Yu，Rongjun
中科院分区：
文献类型：
--
作者：
Sun，Sai;Cai，Chuhua;Yu，Rongjun
当面临不确定性时，个人基于价值的决策会受到预期回报和风险的影响。了解奖励和风险是如何在行为和神经层面上进行处理和整合的，对于建立效用理论至关重要。使用修改后的货币激励延迟任务，其中两个可能的结果（预期奖励）的平均值和可能的结果（风险）的标准差（SD）进行参数化处理和正交化，我们测量了眼球运动，反应时间（RT），和大脑活动时，参与者寻求获得奖励。我们发现，RT的变化作为一个函数的平均值，但不是SD的潜在奖励，这表明预期的奖励是RT的主要驱动力。此外，当潜在奖励的大小（可能结果的平均值）更大时，关注高价值奖励与低价值奖励的目光之间的差异变得更小，而当风险（可能结果的SD）变得更小时，突出了奖励和风险对注意力部署的不同影响。处理平均奖励激活了纹状体。纹状体与杏仁核的正连接和与额上级回的负连接与个体对预期奖励的敏感性相关。相反，处理风险激活了前额叶。它与腹内侧前额叶皮层的正连接和与前中扣带皮层的负连接与风险敏感性的个体差异相关，进一步表明奖励和风险在神经水平上的功能分离。我们的研究结果，基于几种不同的措施，描绘了奖励和风险在非决策背景下的不同表示，并提供洞察这些效用参数如何调节注意力，动机和大脑网络。
When faced with uncertainty, individuals’ value-based decisions are influenced by the expected rewards and risks. Understanding how reward and risk are processed and integrated at the behavioral and neural levels is essential for building up utility theories. Using a modified monetary incentive delay task in which the mean of two possible outcomes (expected reward) and the standard deviation (SD) of the possible outcomes (risk) were parametrically manipulated and orthogonalized, we measured eye movements, response times (RTs), and brain activity when participants seek to secure a reward. We found that RTs varied as a function of the mean but not the SD of the potential reward, suggesting that expected rewards are the main driver of RTs. Moreover, the difference between gazes focused on high vs. low value rewards became smaller when the magnitude of the potential reward (mean of possible outcomes) was larger and when risk (SD of possible outcomes) became smaller, highlighting that reward and risk have different effects on attention deployment. Processing the mean reward activated the striatum. The positive striatal connectivity to the amygdala and negative striatal connectivity to the superior frontal gyrus were correlated with individuals’ sensitivity to the expected reward. In contrast, processing risk activated the anterior insula. Its positive connectivity to the ventromedial prefrontal cortex and negative connectivity to the anterior midcingulate cortex were correlated with individual differences in risk sensitivity, further suggesting the functional dissociation of reward and risk at the neural level. Our findings, based on several different measures, delineate the distinct representations of reward and risk in non-decision contexts and provide insight into how these utility parameters modulate attention, motivation, and brain networks.