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现。然而，有时候等待是值得的，特别是当延迟的结果比直接的结果更有价值的时候。人类和动物经常面临在结果之间做出选择，这些结果可能在延迟和数量上有所不同。有许多个体差异变量与折扣率的差异有关，包括注意缺陷/多动障碍（AHDH）、吸毒成瘾和赌博。冲动的人等待结果的能力较弱，因此倾向于选择延迟较短的选项，即使这些结果的利润要低得多。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）和无能的资金管理。本研究旨在通过实施筛选方法来识别冲动选择的来源，从而促进对时间折现和冲动选择的理解。这项研究是由于观察到冲动有两种不同的途径，一种是通过奖励处理的缺陷，另一种是通过时间处理的缺陷。初步的研究将发展出筛选个体冲动倾向的方法，并确定与时间和/或奖励处理系统中冲动相关的关键缺陷。另外一组研究将开发有针对性的治疗干预措施，以纠正时间和/或奖励处理的缺陷。这种治疗方法可以应用于表现出多动症等疾病的个体，也可以应用于倾向于冲动选择的正常人，以减少追求不良生活方式选择的风险，如吸毒/滥用、赌博等。最后一组研究将通过精确定位与伏隔核神经毒性损伤相关的奖励处理缺陷的性质来研究奖励处理对选择的影响机制，伏隔核已被确定为计算时间折扣中奖励价值的主要候选结构。确定与伏隔核损伤相关的奖励处理缺陷的确切性质，将促进针对多动症和其他破坏自我控制的疾病的靶向治疗技术的进一步发展。这些综合研究将极大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，并为开发针对冲动选择情境中涉及奖励价值计算的关键系统的特定治疗技术提供重要基础。

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.