Functional Imaging of Implicit Marijuana Associations during IAT Performance

描述（由申请人提供）：该项目旨在通过药物相关记忆关联的成像（fMRI）来了解内隐联想过程中涉及的神经基质。受强化药物使用经历影响的复杂的联想学习和记忆过程导致神经生物学后果，包括动机相关的联想记忆的加强，这反过来又影响随后的有意识之外的药物使用行为。这些药物相关的关联效应已被证明与药物使用水平一致相关并可预测药物使用水平。基础科学研究中的联想记忆概念的应用表明，一个人在任何时刻的行为主要受记忆中当前激活模式的支配，而激活通常主要是一个内隐的或相对自动的过程。为了观察与药物相关的关联效应的神经活动的差异，拟议的项目将涉及大麻依赖个体和一组健康对照在大麻内隐关联测试（IAT）的表现期间的受试者之间的比较。此外，受试者内比较将提供与IAT兼容和不兼容试验中记忆关联的神经激活相关的信息，以帮助确定IAT效应的神经相关性。这项拟议中的工作是第一项观察大麻依赖者和非使用者之间神经活动差异的间接关联测试。对药物相关关联的间接评估，如IAT，植根于联想学习原则，联想强度是信息处理的关键决定因素，表现为影响行为的记忆偏差。通过在这种间接测试中的表现引发关联药物相关记忆的激活，有可能增加我们对影响意识意识之外的药物使用行为的关联结构中的个体差异的理解。拟议中的fMRI项目将补充和扩展通过行为测量得出的结果。这是使用多种方法来调查和增加我们对内隐过程及其对成瘾行为的调节影响的理解的一步。成瘾是一种渐进的、复发的状况，一旦形成，如果不持续干预，很难克服。如果理解这些研究不足但有影响力的内隐过程所涉及的神经机制有助于扩大我们对影响持续药物滥用的影响的知识，那么这项工作确实很重要。了解行为的神经介质，如药物相关的内隐关联，可以帮助开发风险降低和治疗干预成分，以提高当前方案的疗效。公共卫生相关性：该项目旨在通过与药物相关的记忆协会的成像来了解参与内隐联想过程的神经基质，这些记忆协会已被证明与药物使用水平一致相关并预测药物使用水平。为了观察神经活动，该项目涉及大麻协会的功能成像（fMRI）在大麻依赖个体和健康对照组之间进行内隐联想测试（IAT）。通过在这种间接的关联测试中的表现来激发关联药物相关记忆的激活，有可能增加我们对影响意识意识之外的药物使用行为的关联结构中的个体差异的理解。

DESCRIPTION (provided by applicant): This project seeks to understand the neural substrates involved in implicit associative processes through the imaging (fMRI) of drug-relevant memory associations. Complex associative learning and memory processes influenced by reinforced drug use experiences result in neurobiological consequences that include the strengthening of motivationally-relevant associative memories, which, in turn, affect subsequent drug use behavior outside conscious awareness. These drug-related associative effects have been shown to consistently correlate with and predict level of drug use. The application of associative memory concepts from basic science research suggests that one's behavior at any moment is governed primarily by the current pattern of activation in memory, and that activation is often primarily an implicit, or relatively automatic process. To observe differences in neural activity of drug-relevant associative effects, the proposed project will involve a between subjects comparison of marijuana dependent individuals and a group of healthy controls during performance on a marijuana-Implicit Association Test (IAT). In addition, a within subjects comparison will provide information relevant to the neural activation of memory associations on compatible and incompatible trials of the IAT to help determine neural correlates of the IAT effect. The proposed work is the first study to observe differences in neural activity between marijuana dependent individuals and non-users on an indirect test of associations. Indirect assessments of drug-relevant associations, like the IAT, are rooted in associative learning principles, with associative strength being a key determinant of information processing expressed as memory biases that influence behavior. By eliciting activation of associative drug-relevant memories through performance on this indirect test, it is possible to increase our understanding of individual differences in associative structures that influence drug use behavior outside of conscious awareness. The proposed fMRI project will complement and extend findings derived through behavioral measures. This is a step toward the use of multiple methods to investigate and increase our understanding of implicit processes and their regulatory influence on addictive behaviors. Addiction is a progressive, relapsing condition and once established, it is difficult to overcome without continual intervention. If understanding the neural mechanisms involved in these under-studied but influential implicit processes helps to expand our knowledge of influences affecting continued drug abuse, then this work is indeed significant. Understanding neural mediators of behavior like drug-related implicit associations can help in the development of risk reduction and treatment intervention components to improve the efficacy of current protocol. PUBLIC HEALTH RELEVANCE: This project seeks to understand the neural substrates involved in implicit associative processes through the imaging of drug-relevant memory associations that have been shown to consistently correlate with and predict levels of drug use. To observe neural activity, the project involves functional imaging (fMRI) of marijuana associations during performance on the Implicit Association Test (IAT) among marijuana dependent individuals and a comparison group of healthy controls. By eliciting activation of associative drug-relevant memories through performance on this indirect test of association, it may be possible to increase our understanding of individual differences in associative structures that influence drug use behavior outside of conscious awareness.