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，因为等待与风险相关；这种现象被称为临时贴现。然而，在某些情况下，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延迟和数量上可能不同的结果之间的选择。有许多个体差异变量与贴现率的差异有关，包括注意力缺陷/多动障碍(AHDH)、吸毒和赌博。冲动的人等待结果的能力较低，因此表现出选择延迟较短的选项的倾向，即使这些结果的利润要低得多。因此，冲动增加了糟糕的生活方式选择(例如，糟糕的饮食、赌博、吸毒)和不称职的理财的风险。目前的建议试图通过实施筛选方法来识别冲动选择的来源，以促进对时间折扣和冲动选择的理解。这项研究是因为观察到冲动有两条不同的途径，一条是通过奖励加工的缺陷，另一条是通过时间加工的缺陷。初步研究将开发方法来筛选个体的冲动倾向，并确定与时机和/或奖励处理系统中的冲动有关的关键缺陷。另一组研究将开发有针对性的治疗干预措施，以纠正时间和/或奖励处理方面的缺陷。这类治疗可以应用于表现出ADHD等障碍的个人，以及倾向于冲动选择的正常人，以降低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查明与伏隔核神经毒性损伤相关的奖赏加工缺陷的性质来考察奖赏加工对选择的影响的机制，该核心已被确定为在时间折扣中计算奖赏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进一步开发靶向治疗技术，用于ADHD和其他破坏自我控制的障碍。这一系列研究的结合将显著提高我们对在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，该技术旨在针对冲动选择情景中涉及奖励价值计算的关键系统。 公共卫生相关性：该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，并进一步了解伏隔核核心在冲动选择情景下奖励价值计算中的作用。这些结果对于理解和治疗导致冲动增加的障碍，如ADHD和冲动性人格障碍，以及准确地确定影响正常个人选择的因素，具有潜在的重要意义。此外，时间折扣的差异显然与吸毒和赌博有关，揭示这些联系的根本来源有可能更好地理解和纠正那些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.