Timing, reward processing and choice

描述（由申请人提供）：延迟的结果往往不如更直接的结果有价值，因为等待与风险有关;这种现象被称为时间折扣。然而，在某些情况下，等待是值得的，特别是当延迟的结果比立即的结果更有价值时。人类和动物经常面临在延迟和数量上可能不同的结果之间做出选择。有许多个体差异变量与折扣率的差异相关，包括注意力缺陷/多动障碍（AHDH），药物成瘾和赌博。冲动型的人不太能够等待结果，因此即使这些结果的利润要少得多，他们也会倾向于选择延迟时间较短的选项。因此，冲动增加了不良生活方式选择的风险（例如，不良饮食、赌博、吸毒）和不善于理财。本研究旨在通过实施筛选方法来识别冲动选择的来源，从而促进对时间折扣和冲动选择的理解。这项研究是由观察驱动的，有两个不同的途径冲动，一个通过赤字奖励处理和赤字的时间处理。最初的研究将开发方法来筛选个人的冲动倾向，并确定与冲动相关的关键缺陷在时间和/或奖励处理系统。另一组研究将开发有针对性的治疗干预措施，以纠正时机和/或奖励处理方面的缺陷。这样的治疗可以应用于表现出诸如ADHD的障碍的个体，以及具有冲动选择倾向的正常个体，以降低追求不良生活方式选择的风险，诸如药物使用/滥用、赌博、最后一组研究将通过精确定位与神经毒性相关的奖励加工缺陷的性质，来检查奖励加工对选择影响的机制。脑桥核核心的病变，其已被确定为用于在时间折扣中计算奖励值的主要候选结构。确定与延髓核病变相关的奖励处理缺陷的确切性质将促进进一步开发用于ADHD和其他破坏自我控制的疾病的靶向治疗技术。这些研究的组合将显著地促进我们对时间折扣任务中促进自我控制与冲动选择的因素的理解，并为开发特定的治疗技术提供重要的基础，这些治疗技术旨在针对冲动选择情况下参与奖励值计算的关键系统。 公共卫生相关性：本项目旨在实施筛选方法，以确定冲动选择行为中个体差异的潜在来源，开发有针对性的治疗技术，以改善奖励加工和时间加工的缺陷，并进一步了解在冲动选择情况下计算奖励值时，丘脑核的核心作用。这些结果对于理解和治疗导致冲动性增加的疾病（如ADHD和冲动性人格障碍）以及确定影响正常人选择的因素具有潜在意义。此外，时间折扣的差异显然与吸毒成瘾和赌博有关，解开这些联系的根本来源有可能更好地理解和纠正导致成瘾倾向形成和持续的因素。

DESCRIPTION (provided by applicant): Outcomes that are delayed tend to be less valuable than more immediate outcomes because waiting is associated with risk; this phenomenon is known as temporal discounting. However, there are occasions where waiting can be worthwhile, especially when the delayed outcome is much more valuable than the immediate outcome. People and animals are frequently confronted with choices between outcomes that may differ in delay and amount. There are a number of individual difference variables that are associated with differences in discounting rates including Attention Deficit/Hyperactivity Disorder (AHDH), drug addiction, and gambling. Impulsive individuals are less able to wait for outcomes and thus show a bias to choose shorter-delayed options even when those outcomes are much less profitable. As a result, impulsivity increases the risk of poor lifestyle choices (e.g., poor diet, gambling, drug taking) and inept money management. The present proposal seeks to advance the understanding of temporal discounting and impulsive choice by implementing screening methods to identify the source of impulsive choice. This research is driven by the observation that there are two distinct pathways to impulsivity, one through deficits in reward processing and one through deficits in temporal processing. Initial studies will develop methods for screening individuals for impulsive tendencies and identifying the key deficits associated with impulsivity in the timing and/or reward processing systems. An additional set of studies will develop targeted therapeutic interventions to redress deficits in timing and/or reward processing. Such treatments could be applied to individuals exhibiting disorders such as ADHD, and with normal individuals with a tendency towards impulsive choice to reduce the risk of the pursuit of poor lifestyle choices such as drug use/abuse, gambling, etc. A final set of studies will examine the mechanisms that underlie the effect of reward processing on choice by pinpointing the nature of the deficits in reward processing associated with neurotoxic lesions of the nucleus accumbens core, which has been identified as the primary candidate structure for the computation of reward value in temporal discounting. Determining the exact nature of the reward processing deficits associated with nucleus accumbens lesions will promote the further development of targeted therapeutic techniques for use with ADHD and other disorders that undermine self-control. The combined set of studies will significantly advance our understanding of factors that promote self- control vs. impulsive choice in temporal discounting tasks and provide a significant foundation for the development of specific therapeutic techniques designed to target the key systems involved in the computation of reward value in impulsive choice situations. PUBLIC HEALTH RELEVANCE: This project aims to implement screening methods for identifying the underlying source of individual differences in impulsive choice behavior, to develop targeted therapeutic techniques for improving deficits in reward processing and temporal processing, and to further understand the role of the nucleus accumbens core in the computation of reward value in impulsive choice situations. The results are potentially significant for understanding and treating disorders which result in increased impulsivity such as ADHD and impulsive personality disorder as well as pinpointing factors that affect choice in normal individuals. In addition, differences in temporal discounting have been clearly linked to drug addiction and gambling and unravelling the underlying source of these links has the potential to better understand and rectify those factors that lead to the formation and persistence of addictive tendencies.