Impaired context-learning (value signal normalization) in the aging brain

摘要 老龄化与对欺诈的敏感性增加和财务决策的损害有关。是 一个有效的财务决策者，除了学会如何获得回报，还必须学会如何 避免损失。当结果是有益的时，强大的大脑系统会加强学习。但不 明确是否重复学习的大脑系统有助于学习避免损失的问题， 在学习避免损失时，“不改变”的结果可能是最好的选择，但它本身不是 内在的回报我们最近的研究结果表明，随着时间的推移，年轻人学会根据 在损失情境中，没有损失的结果会激活大脑中的奖励中心， 学习过程，使他们能够有效地学习如何避免损失和获得收益 奖励相比之下，我们的初步行为研究结果表明，老年人表现出选择性损伤， 学会避免损失。这种与年龄有关的损害可能是由于以下能力的损害： 了解决策背景或更普遍的“积极效应”，他们相对较少关注 消极的结果多于积极的结果。在目前的建议中，我们开发和测试计算模型，以确定 不同类型的学习机制对这些年龄差异的贡献。特别是要 比较在学习背景方面的障碍程度与更多关注的偏见 积极的反馈比消极的反馈更能解释老年人的学习模式。然后，我们将检查 神经相关的最佳拟合模型的年轻和老年参与者。此外，在一个代表 美国人的样本，我们将研究如何在上下文学习和积极性偏见的个体差异与 他们的财务决策能力和对诈骗的敏感性。

ABSTRACT Aging is associated with increased susceptibility to fraud and impairments in financial decision making. To be an effective financial decision maker, in addition to learning how to gain reward, one must also learn how to avoid losses. Powerful brain systems reinforce learning when the outcome is rewarding. However, it is not clear whether reinforcement-learning brain systems contribute to the problem of learning to avoid losses, as when learning to avoid losses, a “no-change” outcome may be the best option available but is not in itself inherently rewarding. Our recent findings indicate that, over time, younger adults learn to adjust based on context such that in loss contexts, having a no loss outcome activates reward centers in the brain and trigger reinforcement-learning processes that allow them to learn as effectively about avoiding losses as gaining rewards. In contrast, our preliminary behavioral findings indicate that older adults show selective impairments in learning to avoid losses. This age-related impairment could either be due to impairments in the ability to learn about the decision context or to a more general ‘positivity effect’ in which they attend relatively less to negative than positive outcomes. In the current proposal, we develop and test computational models to identify the contribution of different types of learning mechanisms to these age differences. In particular, we will compare the degree to which impairments in learning about the context versus a bias to attend more to positive than negative feedback can account for older adults’ learning patterns. We then will examine the neural correlates of the best fitting models for the young and older participants. In addition, in a representative sample of Americans, we will examine how individual differences in context learning and positivity bias relate to their financial decision-making abilities and susceptibility to scams.