The impact of induced anxiety on affective response inhibition

Studying the effects of experimentally induced anxiety in healthy volunteers may increase our understanding of the mechanisms underpinning anxiety disorders. Prior work has shown that experimentally induced anxiety (via threat of unpredictable shock) improves accuracy at withholding a response on the Sustained Attention to Response Task (SART), and in separate studies improves accuracy to classify fearful faces, creating an affective bias. Integrating these findings, in this study, 47 participants at a public science engagement event were recruited to explore the effects of experimentally induced anxiety on an affective version of the SART. On the basis of previous work, we hypothesised that we would see an increased accuracy at withholding a response to affectively congruent stimuli (i.e. increased accuracy at withholding a response to fearful “no-go” distractors under threat of shock). Response accuracy on “no-go” trials was analysed using a two-way ANOVA with factors valence (happy / sad) and condition (threat / safe). Reaction time analysis was performed on “go” stimuli. Prior to analysis, a square root transform was applied to reaction time data as it was not normally distributed. Reaction time to targets (“go” stimuli) was analysed using a two-way ANOVA with factors valence (happy / sad) and condition (threat / safe). Post hoc analyses were run to investigate the effect of STAI anxiety scores and blood alcohol concentration on performance. Pearson’s r correlations between symptom measures (STAI State and Trait scores, and blood alcohol concentration) and reaction time / accuracy data were run.

探究健康受试者经实验诱导的焦虑效应，有助于深化我们对焦虑障碍潜在发病机制的认知。既往研究表明，通过不可预测电击威胁范式诱导的实验性焦虑，可提升受试者在持续注意力反应任务（Sustained Attention to Response Task, SART）中抑制反应的准确率；另有独立研究显示，该焦虑诱导可提升恐惧面孔分类的准确率，进而产生情绪偏差。本研究整合上述发现，招募参与公共科学科普活动的47名受试者，探究实验诱导焦虑对情绪版持续注意力反应任务的影响效应。基于既往研究，我们提出假设：在情绪匹配刺激下，受试者的抑制反应准确率将提升（即电击威胁条件下，对作为分心物的恐惧面孔「no-go」试次的抑制准确率将升高）。本研究针对「no-go」试次的反应准确率，采用双因素方差分析进行统计检验，所纳入的因素为效价（愉悦/悲伤）与实验条件（威胁/安全）。针对「go」试次的刺激开展反应时分析；由于反应时数据不符合正态分布，分析前先对其进行平方根转换。针对靶刺激（「go」试次的刺激）的反应时，同样采用双因素方差分析进行统计检验，纳入因素为效价（愉悦/悲伤）与实验条件（威胁/安全）。随后开展事后检验，以探究状态-特质焦虑问卷（State-Trait Anxiety Inventory, STAI）焦虑得分与血液酒精浓度对任务表现的影响。本研究还针对症状测量指标（STAI状态焦虑得分、特质焦虑得分与血液酒精浓度）与反应时/准确率数据之间的关系，开展皮尔逊积矩相关分析。