抑郁个体对情绪面孔的返回抑制能力不足

探讨抑郁对情绪面孔返回抑制能力的影响。以贝克抑郁量表、自评抑郁量表、CCMD-3和汉密顿抑郁量表为工具筛选出了正常对照组、抑郁康复组和抑郁患者组各17名被试进行了真人情绪面孔线索-靶子任务的行为学实验和事件相关电位(ERP)实验。在线索靶子范式中, 靶子在线索消失后出现, 被试对靶子的位置作出反应。行为学实验显示线索靶子间隔时间(stimulus onset asynchronies, SOA)为14ms时, 正常对照组对中性面孔有返回抑制效应, 抑郁康复组对所有面孔均存在返回抑制效应, 患者组对愤怒、悲伤面孔和中性面孔存在返回抑制效应; SOA为250ms时三组被试均对悲伤面孔存在返回抑制能力不足, 以患者组最突出, 康复组对高兴面孔存在返回抑制能力不足; SOA为750ms时正常组对悲伤面孔存在返回抑制效应, 康复组对高兴和悲伤面孔存在返回抑制能力不足, 患者组对悲伤面孔存在返回抑制能力不足, 对愤怒面孔存在返回抑制效应。在SOA为750ms的条件下, ERP波形特点为正常组对高兴面孔线索P3波幅大于其他组, 对高兴面孔无效提示P1波幅小于其他面孔, 对悲伤面孔有效提示P1波幅小于高兴面孔, 对高兴面孔有效提示P3波幅大于患者组, 对悲伤面孔无效提示P3波幅大于其他组; 康复组对悲伤面孔线索P3波幅大于其他面孔, 对高兴面孔有效提示P3波幅大于患者组, 对悲伤面孔无效提示P3波幅小于正常组; 患者组对悲伤面孔线索P1波幅大于其他组、P3波幅大于其他面孔, 对悲伤面孔无效提示P3波幅小于正常组, 高兴面孔有效提示P3波幅小于其他组。提示抑郁患者对负性刺激有返回抑制能力不足, 这种对负性刺激抑制能力的缺失导致抑郁个体难以抗拒负性事件的干扰而受到不良情绪状态的困扰, 所以他们可能更多的体验到抑郁情绪, 并致使抑郁持续和发展。而抑郁康复个体对高兴、悲伤面孔均有返回抑制能力不足, 这让康复个体能同时感受到正、负性刺激, 从而能保持一种认知和情绪上特定的平衡。

Deficient Inhibition of Return for Emotional Faces in Depression

Depression is a commonly-occurred mental disorder. Researchers have highlighted the attentional bias of depressive disorders, although results have been mixed. The cue-target task has often been used to explore attentional bias; a particular phenomenon revealed by such studies is the inhibition of return (IOR). However, cue-target task has seldom been used so far in the study of depressed patients. The aim of the present study was to investigate the IOR phenomenon in depressed individuals in cue-target task using emotional faces as cues.Control participants who had never suffered depression (NC), participants who had experienced at least two depressive episodes in their lives but were currently remitted (RMD), and participants diagnosed with a current major depressive disorder (MDD), were recruited using BDI, SDS, HAMD and CCMD-3 as tools. Seventeen participants in each group completed a cue-target task in a behavioral experiment that comprised three kinds of experimental condition, two cue types and four face types. Each participant also completed a simpler cue-target task in an event-related potential (ERP) experiment. In this task, a target appeared after a cue and the participant responded to its location.In the behavioral experiment, it was found that when the stimulus onset asynchrony (SOA) was 14 ms, the NC and RMD participants had IOR effects for all faces and MDD participants for angry and sad faces. When the SOA was 250 ms, all three groups all had cue validity for sad faces but the effect was much more marked for the MDD group. When the SOA was 750 ms, the NC participants had an IOR effect for sad faces, the RMD participants had cue validity for angry, happy and sad faces, and the MDD participants had cue validity for sad faces and an IOR effect for angry faces. In the ERP experiment, the NC participants showed a bigger P3 amplitude for happy cue than the other groups, a smaller PI amplitude for happy faces in the invalid cue condition than for other faces, a smaller P1 amplitude for sad faces in the valid cue condition than for other faces, a bigger P3 amplitude for happy faces in the valid cue condition compared with MDD participants, and a bigger P3 amplitude for sad faces in the invalid cue condition compared with other groups. The RMD participants had larger P3 amplitude for sad cue than for other faces, larger P3 amplitude for happy faces in the valid cue condition compared with MDD participants, and smaller P3 amplitude for sad faces in the invalid cue condition compared with NC participants. The MDD participants had a larger P1 amplitude for sad cue compared with other groups, a larger P3 amplitude for sad cue than for other face cues, a smaller P3 amplitude for sad faces in the invalid cue condition compared with NC participants, and a smaller P3 amplitude for happy faces in the valid cue condition compared with other groups.It can be concluded that the MDD participants had cue validity and deficient IOR for negative stimuli. The deficient inhibition of negative stimuli renders them unable to eliminate the interference of negative stimuli and causes the maintenance and development of depression. The RMD participants had cue validity and deficient IOR for both positive and negative stimuli, which enables them to perceive positive and negative stimuli sufficiently and to maintain emotional balance.