Impulsivity and Neural Processing of Rewards

描述(由申请人提供)： 冲动是包括药物滥用在内的许多精神疾病的个性特征，它涉及到对即时奖励的偏爱，而不是延迟奖励，以及对长期后果的忽视。这一应用假设，在高冲动受试者中，腹侧被盖(VTA)多巴胺能奖赏预测系统的失调导致刺激评估的眼眶额叶皮质(OFC)系统和行为监测的前扣带皮质(ACC)系统出现奖赏超敏。提出的实验利用事件相关电位的时间分辨率和功能磁共振的空间分辨率来研究刺激评估和动作监控中的奖赏敏感性。本实验以Barrett冲动性量表为基础，将正常大学生分为高冲动组和低冲动组，分别采用改进的侧翼任务和奖罚性刺激测试，对冲动型受试者的错误激活进行奖惩刺激测试，对冲动型受试者进行被动的S1/S2范式测试，以增强OFC激活对奖赏预测的影响，并采用SI/S2激励性侧翼范式考察OFC和ACC在奖励型决策任务中的相互作用。

DESCRIPTION (provided by applicant): Impulsivity, a personality characteristic of many psychiatric disorders including substance abuse, involves a preference for immediate rewards over delayed rewards and a disregard of long-term consequences. This application hypothesizes that dysregulation of the ventral tegmental (VTA) dopaminergic reward prediction system leads to a reward hypersensitivity in orbitofrontal cortex (OFC) systems of stimulus evaluation and anterior cingulate cortex (ACC) systems of behavior monitoring among highly impulsive subjects. The proposed experiments investigate reward sensitivity in stimulus evaluation and action monitoring utilizing the temporal resolution of ERPs and spatial resolution of fMRI. The experiments employ normal college students screened and separated into high and low impulsive groups, based on the Barrett Impulsivity Scale, participating in a modified flanker task with rewarding and punishing stimuli testing for reduced ACC activation to errors in impulsive subjects, in a passive S1/S2 paradigm testing for enhanced OFC activation to the prediction of reward in impulsive subjects, and an SI/S2 incentive flanker paradigm examining interactions between OFC and ACC in a reward-motivated decision task.