抑郁症患者面孔加工事件相关电位时空模式特征

Characteristics of satiotemporal-pattern of event related potential in face processing of patients with depression

目的:探讨抑郁症患者情绪面孔识别以及倒立效应所诱发的事件相关电位时空模式特点,并与正常对照组比较。方法:实验于2004-07/11在南方医科大学脑研究中心完成。以来自南方医科大学南方医院的14名抑郁症患者和36名自愿健康受试者为研究对象。利用3张不同表情(正性、中性、负性)面孔简笔画图片,以正立和倒立的形式与下述汉字:“喜、思、恐”随机混合构成刺激序列,9类刺激随机顺序呈现共450次(50次/类),让受试者从事简笔画面孔表情识别任务,系统记录正误率。同时观察不同表情和方位图片所诱发的事件相关电位波形的时空分布以及两组的“情绪波”之间的差别。结果:抑郁症组14名受试者中1名女受试者和1名男受试者因为脑电波干扰太大被剔除,其余12名受试者作数据分析;正常对照组36名受试者中3名女受试者和1名男受试者因为脑电干扰太大被剔除,其余32名受试者作数据分析。①抑郁症组的反应时间较对照组延长,正确率下降。抑郁症组和正常对照组均发现事件相关电位成分N210。抑郁症组和对照组在T6,O1,O2都诱发出与面孔刺激相关的事件相关电位成分N210,抑郁症组在T5未诱发出N210。②抑郁症组和对照组的“情绪波”存在明显差异,总体印象是左侧脑区的差异更突出,各组t值的统计参数映像:正立正性情绪与中性情绪的差值组:情绪波265ms左右在左侧颞区明显,290～340ms各区均有,但以左侧突出,515～565ms从左侧枕区向前头部扩布;正立负性情绪与中性情绪的差值组:情绪波165～240ms在左侧额颞区明显,向后以及对侧扩布,315～365ms各区均有向左侧额颞区收缩,415～440ms以左侧颞区为主,465～490ms以后枕区明显;倒立正性情绪与中性情绪的差值组:情绪波410～450ms从右侧颞枕区向前以及对侧扩布;倒立负性情绪与中性情绪的差值组:情绪波205～230ms以前头部以及右侧颞枕区明显,280～305ms以左侧额顶区明显,455～505ms以左侧颞顶区明显。结论:抑郁症患者的情绪面孔识别所诱发的事件相关电位表现异常,尤其是左侧脑区,可能与杏仁体、额前区皮层的受损有关,或与左侧额叶的物质代谢(如磷酸肌酸)异常有关。

AIM： To investigate the characteristics of spatiotemporal pattern of the event-related potentials （ERPs） evoked by the emotional facial recognition and inverted effect in patients with depression and its comparison with normal control group. METHODS： The experiment was carried out in the Cerebral Research Center of Southern Medical University between July and November 2004. Fourteen depressive patients and 36 healthy volunteers were selected from Nanfang Hospital of Southern medical university. Three categories （positive, neutral and negative） of emotional schematic face pictures were used in upright and inverted manners, then formed a stimuli series by mixing with three Chinese words （happy, think, fear）. Randomized stimuli series of 9 categories totally appeared 450 times （50 times per category）. Subjects were required to recognize the emotional schematic faces, and the right rate and error rate were recorded by system. Meanwhile, the spatiotemporal distribution of ERPs wave evoked by different expressions and oriented pictures as well as the differences of ＂emotion-wave＂ between two groups were observed. RESULTS： One in 14 female subjects in the depression group and one male subject were excluded because of great brain wave interference, datas of rest 12 subjects were analyzed; One female and one male in 36 subjects in the normal control group were excluded because of great brain wave interference, datas of rest 32 subjects were analyzed. ① Reaction time in the depression group was longer than that in the control group, and the correct rate was decreased. Conponent N210 of ERPS in the ＂emotion wave＂ was found in the normal control group and the depression group, and N210 of ERPs was induced on T6,O1,O2 in both groups, while that wasn＇t induced on T5 in the depression group. ② The emotion-wave＂ between two groups was significantly different, especially in left cerebral zone. t value of statistical parameter reflection in each group： Difference value group of Upright positive motion and neurtral motion ： The emotionwave （265 ms） in left temporal region was significant, and existed in each region （290-340 ms）, especially in the left side. and spreaded from left occipital region to anterior region （515-565 ms）; Difference value group of upright positive motion and neurtral motion： The emotion wave in left frontotemporal region （165-240 ms） was obvious, and spreaded to posterior region and right hemisphere; The emotion-wave in all regions contracted to left frontotemporal region （315-365 ms）, and was mainly spreaded to left temporal region （415-440 ms）, and was significant beyond posterior occipital region （465-490 ms）. Difference value group of inverted positive motion and neurtral motion： The emotion-wave spreaded from right temporooceipital region （410-450 ms） to anterior and opposite hemisphere; Difference value group of reverted positive motion and neurtral motion： The emotion-wave was significant in anterior and right temporo-occipital region （205-230 ms）, that in the left fronto-partial region （280-305 ms） was obvious, and that in left temporo-occipital region （455-505 ms） was significant. CONCLUSION： The dysfunction of ERPs induced by emotional face cognition of patients with depression exists, especilly in left cerebral cortex may relate to injuries of amygdaloidal body and prefrontal cortex, or relate to abnormal metabolism （such as creatine phosphate） of left frontal lobe.