奖赏决策中自控与冲动的神经机制

Neural Mechanisms of Self-Control and Impulsivity in Reward Decision-Making

奖赏决策中的自控是指为了获得更大价值或更长远利益而抵制即时诱惑的行为模式,而冲动则是指相反的选择偏好。自控与冲动的脑区空间定位是由不同的神经区域在不同决策阶段参与发挥作用的:在决策前期,无论是自控还是冲动决策都有边缘系统或旁边缘系统的参与,包括腹侧纹状体、腹内侧前额皮质、后扣带皮质等;而在决策后期,额顶叶区域和背外侧前额皮质可能在自控决策中发挥决定作用,边缘结构和眶额皮质可能在冲动决策中起支配作用。此外,从奖赏类型角度来看,二级奖赏与初级奖赏既共享一些脑区域如边缘系统,又拥有独特的脑区定位如眶额皮质。时间进程方面,相关的ERP研究表明自控与冲动决策会引起早期成分P1、N1以及晚期成分P3、ERN等成分的幅度变化。未来研究的方向包括设计更严密的实验范式和考察分析大脑各个子区域的单独作用以及彼此间的交互作用。

In reward decision-making, self-control is the choice pattern of resisting instant temptation in order to gain more valuable or long-run benefits, while impulsivity is the opposite preference. In different decision phases, dif- ferent neural regions play roles in the spatial orientation of brain regions of self-control and impulsivity： in early stage of decisionmaking and posterior cingulate , limbic or paralimbic cortex, including ventral striatum, ventral medial prefrontal cortex cortex, involve in both self-controlled and impulsive decisions; in later period of decision- making, fronto-parietal and dorsolateral area mainly play an important role in self-controlled decisions, while limbic system and orbitofrontal cortex possibly play a dominate part in impulsive decisions. In addition, seen from point of reward types, secondary rewards share some brain regions such as limbic cortical with primary rewards, as well as its unique areas such as orbitofrontal cortex. With respect to ERP studies of time course, self-controlled and impul- sive decisions will give rise to amplitude of fluctuation of some ERP components, such as early component P1 and N1, later component P3, ERN and so on. The future research should investigate the independent effect of each subregion and their interactive effects, incorporating more precise experimental desi~ and brain location results.