Neural recruitment during self-control of smoking: An fMRI paradigm

描述(由申请人提供)：食欲过程(例如，寻求奖励和渴望的某些方面)只代表成瘾的一个方面；对药物使用施加“自我控制”的失败尝试是物质依赖的临床诊断的内在因素。研究自我控制的大脑基础的尝试通常依赖于实验室模型，例如决策任务(例如，爱荷华州赌博任务)和快速抑制控制测试(例如，进行/不进行任务)，这些任务与戒毒没有确定的相关性。我们建议使用功能磁共振成像(FMRI)结合一种专门的设备，在扫描环境中允许吸入香烟烟雾，更直接地识别自我控制的底物。50名吸烟者(戒烟12小时)将完成一项通过成功的试点工作而发展起来的“吸烟自我控制挑战”。这项任务包括两种类型的20秒试验：“烟雾不可用”试验，参与者被告知允许吸入香烟烟雾的阀门被关闭；以及“烟雾可用”试验，在该试验中，烟雾立即可用，但鼓励参与者“尽量不要在这些回合中吸烟”。主要的功能测量将是参与者戒烟的可吸烟试验和没有吸烟的试验(“自愿戒烟”--“不可吸烟”)之间的功能磁共振信号差异。在每一次试验中(通过按下按钮)将测量渴望，以允许其协同变化，以及允许评估其在自愿禁欲期间对神经活动的潜在缓和作用。FMRI任务将在相隔大约两周的两次会议中进行。根据初步数据，我们预计自愿禁欲将与右侧前额叶腹外侧和背外侧以及背侧前扣带回皮质和辅助运动区的神经活动增加有关。将应用标准心理测量学技术来评估任务期间性能和功能磁共振信号变化的可靠性和短期稳定性。额外两天的行为测试将允许在任务中的表现与既定的决策、抑制控制和个性测量相关。拟议中的方法将允许对支撑自我控制的神经系统进行成像研究，补充现有用于研究对香烟和滥用药物的渴望的成像方法。随着基本程序的操作和使用，这个为期两年的项目应该会对自我控制的基础产生有价值的见解，具有基础科学和临床意义。

DESCRIPTION (provided by applicant): Appetitive processes (e.g., reward-seeking and some aspects of craving) represent only one side of addiction; failed attempts to exert "self-control" over one's drug use are built-in to the clinical diagnosis of substance dependence. Attempts to study brain substrates of self-control have generally relied on laboratory models, such as decision-making tasks (e.g., the Iowa Gambling Task) and speeded tests of inhibitory control (e.g., the Go/No-Go Task) that have uncertain relevance to abstaining from drug use. We propose to identify substrates of self-control more directly using functional Magnetic Resonance Imaging (fMRI) in conjunction with a specialized apparatus that allows cigarette smoke inhalation in the scanning environment. Fifty cigarette smokers (abstinent 12 h) will complete a "Smoking Self-Control Challenge" that has been developed through successful pilot work. The task includes two types of 20-sec trials: "Smoke Unavailable" trials in which participants are signaled that a valve allowing cigarette smoke inhalation is closed, and "Smoke Available" trials, in which smoke is immediately available, but participants are encouraged to "try not to smoke on as many of these rounds as you can manage". The primary functional measure will be the difference in fMRI signal between Smoke Available trials in which the participant abstains, and trials in which smoke was not available ("Voluntary Abstinence" - "Smoke Unavailable"). Craving will be measured on every trial (by button presses) to allow for its covariation, as well as to allow assessment of its potential moderating effect on neural activity during voluntary abstinence. The fMRI task will be given during two sessions separated by approximately two weeks. Based on preliminary data, we anticipate that voluntary abstinence will be associated with increased neural activity in the right ventrolateral and dorsolateral prefrontal cortex as well as in the dorsal anterior cingulate cortex and supplementary motor area. Standard psychometric techniques will be applied to assess the reliability and short-term stability of performance and of fMRI signal change during the task. Two additional days of behavioral testing will allow performance on the task to be related to established measures of decision-making, inhibitory control, and personality. The proposed method will allow imaging studies of neural systems underlying self-control, complimenting existing imaging methods used to study craving for cigarettes and drugs of abuse. With the primary procedures already operational and in use, this 2-year project should yield valuable insights into the substrates of self-control, with both basic science and clinical implications.