Development of a Novel Trial-by-Trial Consequence Human Delay Discounting Task

描述（由申请人提供）：延迟折扣是一种冲动的行为模型，它反映了个体对较小的早于较大的晚奖励的相对偏好。因此，它模拟了药物依赖的一种基本行为：选择药物使用的即时但短暂的欣快效应，而不是持续禁欲带来的延迟但更有价值的健康和社会功能改善。延迟折扣和药物滥用之间的关系已经在人类和非人类动物研究中进行了研究。然而，一个问题仍然是人类和非人类动物延迟折扣任务评估相同的过程。人类和非人类动物研究通常都涉及在小的即时奖励和大的延迟奖励之间提供一系列选择。然而，非人类动物折扣任务涉及逐个试验的结果，这要求受试者在每次选择试验中都经历偶然的延迟和奖励交付。人类贴现任务通常涉及假设的后果。虽然在人类研究中使用的“潜在的真实的奖励”方法为随机选择的选择试验提供了实际结果，但这些结果是在整个任务完成后才产生的。因此，在潜在的真实的奖励方法中，参与者的选择受到承诺或对偶然结果的预期的影响，而不是在会话中的直接操作经验，可以影响后续试验中的选择行为。考虑到与药物滥用相关的非人动物延迟贴现数据的丰富性，将促进转化研究，以获得与非人动物方法更密切相关的人类贴现方法。因此，在使用延迟折扣研究药物滥用个体的冲动决策中，一个重要的科学步骤是开发用于评估人类折扣的方法。虽然已经开发了一些人的折扣程序，采用试验的试验结果，在拟议的研究中试行的程序可能比这些现有的程序，包括更短的任务持续时间，缺乏概率强化作为混淆，并保证数据点的确定性的优势。由于药物滥用研究中的延迟贴现程序涉及药物滥用个体和非药物滥用个体，因此将在可卡因依赖个体和人口统计学匹配的非药物依赖个体中开发这种新型延迟贴现程序。一个扩展电池的先前使用的延迟折扣条件，涉及假设的和潜在的真实的奖励，以及一份问卷测量冲动，将评估与新的任务进行比较。组间所有折扣测量的比较可能提供趋势，从而保证将来更大的研究将这些组与这组折扣任务进行比较。最终，该项目可能提供一个强有力的工具，在药物依赖的冲动性的研究，并提供可卡因依赖和冲动性的重要信息。公共卫生相关性：一项在可卡因依赖个体和非药物依赖对照个体中进行的行为研究将被用来开发一种新的研究药物滥用中冲动决策的程序。广泛的现有行为冲动的措施将进行评估，这将扩大我们的理解与可卡因滥用相关的决策受损。由于可卡因滥用导致的冲动性已知会导致公共健康危害，包括通过冲动行为传播艾滋病毒，因此这项研究最终应该为可卡因预防和治疗工作提供重要信息。

DESCRIPTION (provided by applicant): Delay discounting is a behavioral model of impulsivity that indexes an individual's relative preference for smaller sooner over larger later rewards. It therefore models a fundamental behavior in drug dependence: choosing the immediate but short-lived euphoric effects of drug use over the delayed but more valuable improvements in health and social functioning that come with sustained abstinence. The relation between delay discounting and drug abuse has been studied in both human and nonhuman animal research. However, a concern remains whether human and nonhuman animal delay discounting tasks assess the same processes. Both human and nonhuman animal studies typically involve presenting a series of choices between a small immediate reward and a larger delayed reward. However, nonhuman animal discounting tasks involve trial-by-trial consequences, which require the subject to experience contingent delays and reward delivery with every choice trial. Human discounting tasks typically involve hypothetical consequences. Although "potentially real reward" methods that have been used in human research provide actual consequences for randomly selected choice trials, those consequences are delivered after the entire task is finished. Therefore, with potentially real reward methods, participants' choices are influenced by the promise or anticipation of contingent consequences, rather than direct operant experience within the session that can influence choice behavior on subsequent trials. Given the wealth of nonhuman animal delay discounting data relevant to drug abuse, it would facilitate translational research to have available human discounting methods that are more closely related to nonhuman animal methods. Therefore, an important scientific step in using delay discounting to investigate impulsive decision making in drug abusing individuals is to develop methods for assessing discounting in humans with trial-by-trial consequences. Although a few human discounting procedures have been developed that employ trial-by-trial consequences, the procedure to be piloted in the proposed study may have advantages over these existing procedures, including shorter task duration, the lack of probabilistic reinforcement as a confound, and guaranteed determinacy of data points. Because delay discounting procedures in the study of drug abuse have involved both drug abusing individuals and non-drug abusing individuals, this novel delay discounting procedure will be developed with cocaine dependent individuals and demographically matched non-drug dependent individuals. An extended battery of previously utilized delay discounting conditions involving hypothetical and potentially real rewards, as well as a questionnaire measure of impulsivity, will be assessed for comparison with the novel task. The comparison of all discounting measures between groups may provide trends that warrant a future larger study comparing these groups with this set of discounting tasks. Ultimately, this project may provide a powerful tool in the study of impulsivity in drug dependence, and provide important information on cocaine dependence and impulsivity. PUBLIC HEALTH RELEVANCE: A behavioral study in cocaine dependent individuals and non-drug dependent control individuals will be used to develop a novel procedure for studying impulsive decision making in drug abuse. A wide range of existing behavioral impulsivity measures will be assessed that will extend our understanding of impaired decision making associated with cocaine abuse. Because impulsivity resulting from cocaine abuse is known to result in public health harms, including the spread of HIV, through impulsive behavior, this study should ultimately lead to important information for cocaine prevention and treatment efforts.