Reward Sensitivity in Depression: A Biobehavioral Study

描述（由申请人提供）：近年来，许多研究者都对发现情绪和情绪障碍的神经心理学基础感兴趣。这些模型中被广泛研究的一个是Davidson的接近-退缩模型（Davidson, 1998），该模型假设动机和情感两个独立的神经系统，并假设这些系统负责对情绪刺激反应的个体差异，或“情感风格”。该模型还提出，这些系统的异常在情绪障碍中起着病因学作用：抑郁症的特征是寻求奖励行为的缺陷（即，接近动机），焦虑的特征是对厌恶刺激的退缩倾向（即，退缩动机）。这些异常也被假设与额叶激活的特定不对称有关（抑郁=左额叶减少；焦虑=右额叶增加）。虽然有几位研究人员发现了对这一模型的支持，但没有研究直接测试假设的额叶不对称是否反映了抑郁症中的这种“低接近风格”。这个项目将通过比较抑郁个体和非抑郁个体在操作接近动机和退缩动机时的脑电图激活来验证这一假设。这项研究还将能够探索动机和脑电图不对称之间的关系是否对具有特定临床特征（例如，共病焦虑症，慢性抑郁症）的个体有所不同。这个项目不仅能够解决动机和抑郁之间的关系，而且还将通过梳理抑郁症的生物学相关性来进一步理解抑郁症的异质性。

DESCRIPTION (provided by applicant): In recent years, many researchers have been interested in discovering a neuropsychological basis of emotion and emotional disorders. One of the more widely studied of these models has been Davidson's approach-withdrawal model (Davidson, 1998), which posits two separate neural systems of motivation and emotion and hypothesizes that these systems are responsible for individual differences in reactivity to emotional stimuli, or "affective styles." The model also proposes that abnormalities in these systems play an etiological role in emotional disorders: depression is characterized by a deficit in reward seeking behavior (i.e., approach motivation) and anxiety is characterized by a tendency to withdraw from aversive stimuli (i.e., withdrawal motivation). These abnormalities are also hypothesized to be associated with specific asymmetries in frontal activation (depression = decrease in left frontal; anxiety = increase in right frontal). While several researchers have found support for this model, no study has directly tested whether the hypothesized frontal asymmetry reflects this "low approach style" in depression. This project will be able to test this hypothesis by comparing the EEG activation of depressed and non-depressed individuals during tasks that manipulate approach and withdrawal motivation. This study will also be able to explore whether the relationship between motivation and EEG asymmetry is different for individuals with particular clinical characteristics (e.g., a comorbid anxiety disorder, chronic depression). This project will not only be able to address the relationship between motivation and depression but will also further the understanding of the heterogeneity of depression by teasing apart its biological correlates.