Value-Based Decision-Making Following Medial Temporal Lobe Lesions

做出最佳决策取决于对选择价值的认识。重要的信息来源 关于选择的价值是先前的经验：积极的经验比消极的更有可能是 再次选择。这种基于价值的学习长期以来一直被认为是试错式增量学习的领域 由皮质-纹状体系统调节的学习。然而，最近的证据表明，在某些情况下 调节情景记忆的内侧颞叶(MTL)也可能有助于基于价值的学习。 然而，人们对MTL何时以及如何做出贡献知之甚少。 在这个提案中，我们提出了一种新的方法来概念化MTL在利用的决策中的作用 该系统的已知计算特性。具体地说，MTL介导的情节记忆 表征是灵活的，不仅服务于记忆，而且还服务于可能的新奇场景的表征。 我们假定，MTL提供的代表性灵活性对决策很重要 无论何时需要在不同的体验中集成价值信息。情况是这样的：1) 价值信息因报酬或有变动而需要更新；2)当价值信息 不是直接可用的，而是在经验中泛化的；以及3)当值表示需要 从头开始建造。我们系统地检查了这三种MTL病变患者的表现。 范例案例和测试关于基于价值的学习和基于价值的学习 决策将受到损害。 组成这一建议的研究有可能加深我们对MTL在以下方面的作用的了解 更高层次的认知，打破通常认为的过程之间的赤裸裸的界限 参与情节记忆和决策。此外，预计这些研究将具有 MTL病理对一系列神经学和精神病学人群的重要临床意义。 了解MTL参与决策的范围和性质不仅将有助于了解 这些人群中决策障碍的性质，也将指导临床评估和理论 知情干预。

Making optimal decisions depends on appreciation of the value of choices. An important source of information about the value of choices is prior experience: Positive experiences are more likely than negative ones to be selected again. Such value-based learning has long been considered the domain of trial-and-error incremental learning mediated by a cortico-striatal system. Recent evidence, however, suggests that in some conditions the medial temporal lobe (MTL), which mediates episodic memory, may also contribute to value-based learning. However, when and how the MTL contributes is poorly understood. In this proposal we put forth a novel way to conceptualize the role of the MTL in decision-making that exploits the known computational characteristics of that system. Specifically, MTL-mediated episodic memory representations are flexible and serve not only memory but also the representation of possible novel scenarios. We postulate that the representational flexibility afforded by the MTL is important for decision-making whenever value information needs to be integrated across distinct experiences. Such is the case when 1) value information needs to be updated as a result of shifting reward contingencies; 2) when value information is not directly available but is generalized across experiences; and 3) when value representations need to be constructed de novo. We systematically examine the performance of patients with MTL lesions in these three paradigmatic cases and test specific predictions about the conditions in which value-based learning and decision-making will be impaired. The studies comprising this proposal have the potential to deepen our understanding of the role of the MTL in higher-level cognition and to break down the stark boundaries commonly assumed between processes involved in episodic memory and decision-making. Further, it is anticipated that these studies will have important clinical implications for a range of neurological and psychiatric populations with MTL pathology. Understanding the scope and nature of MTL involvement in decision-making not only will shed light on the nature of decisional impairments in these populations but also will guide clinical assessment and theoretically informed interventions.