Functional Imaging of Implicit Marijuana Associations during IAT Performance

描述（由申请人提供）：本项目旨在通过药物相关记忆关联的成像（fMRI）了解涉及内隐联想过程的神经基质。受强化吸毒经验影响的复杂联想学习和记忆过程导致神经生物学后果，包括动机相关联想记忆的加强，这反过来又影响有意识意识之外的后续吸毒行为。这些与药物相关的联想效应已被证明与药物使用水平一致相关并预测药物使用水平。基础科学研究中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当前记忆激活模式的支配，而这种激活通常主要是一个隐性的或相对自动的过程。为了观察药物相关联想效应的神经活动差异，本项目将在受试者之间比较大麻依赖个体和健康对照组在大麻内隐联想测验（IAT）中的表现。此外，受试者内部比较将提供与内测相容和不相容试验中记忆关联的神经激活相关的信息，以帮助确定内测效应的神经关联。这项提议的工作是第一个通过间接关联测试来观察大麻依赖者和非使用者之间神经活动差异的研究。药物相关关联的间接评估，如IAT，根植于联想学习原则，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。通过在这个间接测试中的表现来激发联想药物相关记忆的激活，有可能增加我们对在有意识意识之外影响药物使用行为的联想结构的个体差异的理解。拟议的功能磁共振成像项目将补充和扩展通过行为测量得出的结果。这是朝着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迈出的一步。成瘾是一种渐进的、反复发作的状态，一旦形成，没有持续的干预就很难克服。如果理解这些未被充分研究但有影响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认识，那么这项工作确实很重要。了解药物相关内隐关联等行为的神经介质有助于开发降低风险和治疗干预成分，以提高现有方案的有效性。公共卫生相关性：本项目旨在通过与药物相关的记忆关联的成像来了解涉及内隐联想过程的神经基质，这些记忆关联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，本项目利用功能成像（fMRI）对大麻依赖个体和健康对照组在进行内隐联想测验（IAT）时的大麻联想进行观察。通过在这种间接关联测试中的表现来激发联想药物相关记忆的激活，有可能增加我们对在有意识意识之外影响吸毒行为的联想结构的个体差异的理解。

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.