Age and individual differences in reinforcement learning: A behavioural and electrophysiological study

适应性行为依赖于使用绩效反馈来指导行为的能力。积极和消极的反馈对提高表现都很重要，表明当前行为的继续或调整，以及有效地部署注意力资源。绩效监测在儿童和青少年时期尤为重要，因为他们在社会和教育环境中不断面临新的、往往具有挑战性的学习经历。有证据表明，大脑奖励系统的发展是长期的，这些不成熟可能对个人如何评估绩效反馈有深远的影响。从头皮记录的事件相关电位（ERPs）可用于检查表现监测及其背后的神经机制。很少有研究系统地考察ERP对整个开发过程中绩效反馈的反应。重要的是，绩效监测传统上是针对货币反馈进行调查的。然而，最显著的反馈信号可能是社会性的，消极的社会评价可能是一个强有力的信号，导致强烈的大脑奖励反应。方法和结果的不一致提高了个体对消极和积极反馈的反应差异的可能性，这可能部分取决于动机因素，例如内化和外化特征中分别发现的个体对惩罚和奖励的敏感性差异。本研究的主要目标是解决现有的不一致性，并使用ERP方法系统地检查对积极和消极绩效反馈（包括货币和社会）的反应的年龄差异。鉴于从儿童期到青春期情绪和行为障碍的急剧增加，在青春期和成年期出现全阈值障碍之前，识别与奖励相关的功能障碍的早期神经标记可能尤为重要。奖励相关的erp可能是理想的生物标志物，用于研究儿童在青春期过渡期间出现的奖励敏感性和内化/外化特征的变化。因此，本研究的第二个目标是检验内化/外化特征与从童年晚期到成年早期对奖罚表现反馈的反应性降低的假设神经标记之间的关系。如果要将强化学习误差相关信号的调节解释为生物标志物或风险指标，那么对其功能意义的更清晰理解至关重要。这是朝着最终目标迈出的重要的第一步，最终目标是将儿童和青少年时期看到的神经标记与成年后更严重的内化/外化问题的发展联系起来。

Adaptive behaviours rely on the ability to use performance feedback to guide behaviour. Both positive and negative feedback are important for improving performance, signaling either a continuation or an adjustment of the current behaviour and for the efficient deployment of attentional resources. Performance monitoring is particularly important during childhood and adolescence since they are constantly faced with new, often challenging, learning experiences in social and educational settings. Evidence suggests that there is protracted development of the brain reward system and these immaturities may have profound effects on how individuals evaluate performance feedback. Event-related potentials (ERPs) recorded from the scalp can be used to examine performance monitoring and the neural mechanism underlying it. Few studies have systematicallyexamined ERP responses to performance feedback across development. Importantly, performance monitoring has been traditionally investigated in response to monetary feedback. The most salient feedback signals may, however, be social in nature, and negative social evaluation is likely a potent signal leading to strong brain reward responses. Inconsistencies in methodology and results raise the possibility that differences in how individuals respond to negative and positive feedback may depend, in part, on motivational factors such as individual differences in sensitivity to punishment and reward as found with internalizing and externalizing traits, respectively. The primary goal of the proposed study is to address existing inconsistencies and systematically examine age differences in responses to positive and negative performance feedback (both monetary and social) using an ERP approach. In light of the drastic increase in mood and behavioural disorders from childhood to adolescence, it may be especially important to identify early neural markers of reward-related dysfunction that might precede the emergence of a full-threshold disorder in adolescence and adulthood. Reward-related ERPs may be ideal biomarkers for studying changes in reward sensitivity and internalizing/externalizing traits that emerge as children transition through puberty. Hence, the secondary goal of this study iss to examine the association between internalizing/externalizing traits inrelation to a putative neural marker of diminished responsiveness to reward and punishment performance feedback from late childhood to young adulthood. Reaching a clearer understanding of the functional significance of reinforcement learning error related signals is crucial if their modulation were to be interpreted as biomarkers or risk indicators. This is an important first step toward the eventual goal of linking a neural marker seen in childhood and adolescence to the development of more severe internalizing/externalizing problems in adulthood.