Reward context and brain signatures of drug abuse risk in adolescents

青少年药物滥用风险的奖励背景和大脑特征

• 批准号: 9316900
• 负责人: James M Bjork
• 金额: $ 19.38万
• 依托单位: VIRGINIA COMMONWEALTH UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-08-15 至 2019-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9316900
• 关键词: Address; Adolescence; Adolescent; Adolescent Risk Behavior; Adult; Affect; Affective; Age; Alcohol or Other Drugs use; Attention; Behavior; Behavior Therapy; Brain; Cartoons; Cognitive; Cues; Data; Decision Making; Development; Dorsal; Drug abuse; Drug usage; Emotional; Emotions; Event; Feedback; Functional Magnetic Resonance Imaging; Human; Imagery; Incentives; Individual; Learning; Literature; Measures; Monitor; Motivation; Motor; Patient Self-Report; Pattern; Performance; Policies; Prefrontal Cortex; Process; Reaction; Reaction Time; Recruitment Activity; Research; Resources; Rewards; Risk; Risk Behaviors; Signal Transduction; Structure; Substance Use Disorder; Teenagers; Testing; Ventral Striatum; age group; alcohol use initiation; base; behavior change; causal model; comparison group; contingency management; executive function; imaging study; neuroimaging; novel; prevent; programs; response; reward processing; sustained attention; theories; vigilance

Adolescents are notorious for risky behavior, such as drug and alcohol use initiation. A popular theory posits that adolescent risk-taking is partly attributable to robust functioning of earlier-developing mesolimbic motivational neurocircuitry that is poorly controlled by immature frontocortical executive-control neurocircuitry. Functional magnetic resonance imaging (fMRI) findings of increased mesolimbic recruitment (including ventral striatum (VS)) by rewards in adolescents compared to adults support this theory, in that activation of VS reflects covert emotional responses to incentives. Other studies, however, have shown blunted VS recruitment by reward-predictive cues in adolescents compared to adults. Task features may explain this discrepancy, but have never been systematically explored within-subject in age-group comparison. For example, tasks that elicited relatively increased VS activation in adolescents have featured colorful imagery, payoffs of uncertain magnitude, making choices, and cue-contingency learning. Conversely, studies have shown reduced VS activation by reward prospects in adolescents in tasks with explicit payoffs for vigilance-intensive motor performance. Adolescent motivational neurocircuitry may be especially activated by the affective components of rewards, whereas the fully-developed adult brain may more robustly recruit VS as part of a fully-developed executive-control feedback loop (that includes VS to incorporate incentive information) to sustain attention. Notably, the VS is also recruited by vigilance in adults even in non-incentivized contexts. During instrumental behavior, VS recruitment in adolescents may be primarily driven by the affective components of reward, whereas VS recruitment in adults may primarily reflect optimal attention allocation. This R21 project will launch a research program aimed at providing critical contextual nuance to the development of human reward processing. Neurotypical adolescents and adults will perform a novel fMRI reward task that holds constant the expected value of all rewards, but varies whether rewards are 1): explicit, 2) dependent on vigilance-intensive responding, and 3) dependent on a successful choice versus a single response option. Finally, dynamic causal modeling will be employed to measure corticostriatal connectivity as a function of age and reward demands. If adolescents show greater VS activation by choosing responses for rewards or for uncertain payoffs, and adults show greater VS responses to reward in executive control-demanding trials, it will help resolve controversial literature, and clarify reward contexts that best engage motivational circuitry in adolescents. Discovering the incentive contexts that most strongly engage adolescent motivational neurocircuitry can inform each of: a) policies to prevent risky behavior in teens, b) contingency management and other incentive-based therapies for behavior change in adolescence, and c) components of longitudinal developmental projects, by identifying reward task features that yield the most robust mesolimbic signal, and are most germane to drug abuse risk.

青少年因危险行为而臭名昭著，例如开始吸毒和酗酒。一个流行的理论认为 青少年的冒险行为部分归因于早期发育的中脑边缘的强大功能 不成熟的额皮质执行控制神经回路难以控制的动机神经回路。 功能性磁共振成像 (fMRI) 发现中脑边缘募集增加（包括腹侧 与成人相比，青少年纹状体（VS）的奖励支持了这一理论，因为 VS 的激活 反映了对激励的隐性情绪反应。然而，其他研究表明 VS 募集减弱 与成人相比，青少年的奖励预测线索。任务特征可以解释这种差异，但是 从未在年龄组比较中对受试者进行系统性探索。例如，任务 在青少年中引起相对增加的 VS 激活具有丰富多彩的图像，不确定的回报 大小、做出选择和提示应急学习。相反，研究表明 VS 降低 青少年在执行具有明确回报的警戒密集型运动任务时通过奖励前景激活 表现。青少年动机神经回路可能特别被情感成分激活 奖励，而完全发育的成人大脑可能会更强有力地招募 VS 作为完全发育的大脑的一部分 执行控制反馈回路（包括 VS 以纳入激励信息）以维持注意力。 值得注意的是，即使在没有激励的情况下，成年人的警惕性也会被招募。器乐演奏期间 行为，青少年的 VS 招募可能主要由奖励的情感成分驱动， 而成人的 VS 募集可能主要反映了最佳的注意力分配。 R21项目将启动 旨在为人类奖励的发展提供关键背景细微差别的研究计划 加工。神经典型的青少年和成年人将执行一项新颖的功能磁共振成像奖励任务，该任务保持恒定 所有奖励的预期值，但奖励是否 1)：明确，2) 依赖于警惕密集型 响应，3) 取决于成功的选择与单一的响应选项。最后，动态因果 将采用建模来测量皮质纹状体连接作为年龄和奖励需求的函数。如果 青少年通过选择奖励或不确定回报的反应来表现出更大的 VS 激活，而成年人 在执行控制要求较高的试验中表现出更大的 VS 对奖励的反应，这将有助于解决有争议的问题 文献，并阐明最能激发青少年动机回路的奖励环境。发现 最强烈地参与青少年动机神经回路的激励环境可以告知：a） 预防青少年危险行为的政策，b) 应急管理和其他基于激励的疗法 青春期的行为改变，以及 c) 纵向发展项目的组成部分，通过识别 奖励任务特征能够产生最强大的中脑边缘信号，并且与药物滥用风险最密切相关。