抑郁症患者汉字情绪词事件相关电位的时空模式

Spatiotemporal pattern of event related potential in patients with depression during Chinese emotional content words recognition

目的:采用情绪词识别和事件相关电位结合的实验设计,观察抑郁症患者负性认知偏差的神经电生理特征。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观察对象。利用3张不同情绪色彩的词语(“喜、思、恐”,分别代表正性、中性、负性情绪色彩)图片,随机混合构成刺激序列,3类刺激随机顺序呈现共150次(50次/类),让受试者从情绪词识别任务,系统记录正误率。同时观察抑郁症患者与正常人群的反映情感调节的″情绪波″的时空模式差异,以及行为学指标差异。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[(734.08±86.87),(654.40±94.99)ms,t=2.44,P<0.05];正确率降低[(86.24±13.92)%,(92.32±4.79)%,t=2.11,P<0.05],Zung抑郁自评量表评分分值增高[(51.50±8.95)分,(33.7±6.53)分,(t=4.85,P<0.001)]。②抑郁症组和对照组的“情绪波”存在明显差异,比较抑郁症组与对照组各自的正性情绪与中性情绪的差值(A组)、负性情绪与中性情绪的差值(B组),以了解富含感情色彩的情绪和中性情绪词语所诱发的差异(“情绪波”)变化。A组:情绪波80～100ms左右在右侧颞区向中央区扩布,120～140ms以右侧额颞区明显,160～200ms右侧颞区向左侧额颞区扩布,220～240ms右侧额区向左侧颞枕区扩布,280～300ms右侧颞区向左侧额颞区扩布,500ms左右以右侧额区明显;B组:情绪波160～200ms在右侧额颞区明显,240～260ms以左侧颞枕区明显,300～320ms左侧额颞枕区向额区收缩,380～400ms以右侧颞枕区明显,440～460ms以右侧额区明显,540ms以左侧颞枕区明显。总体印象是右侧脑区的差异更突出,经成组t检验,抑郁症组与对照组差异有显著性。结论:抑郁症患者的行为学反应异常和认知功能受损,存在负性认知偏差。抑郁症患者的情绪词识别所诱发的事件相关电位表现异常。情感调节加工的异常提示与汉字情绪词识别关系密切的脑内结构复杂,可能是网状结构模式,抑郁症对情绪加工过程的影响并非涉及个别的独立的皮层和核团(如额前区皮层、杏仁体),其所累及的结构非常广泛;脑优势半球方面异常可能与患者觉察和评估情绪刺激时,在不同阶段选择性抑制前额叶左、右半球不同区域的功能整合有关。

AIM： To observe the neureelectrophysiological characteristics of the negative cognition deviation in patients with depression by use of emotional content Chinese words recognition combined with event related potentials. METHODS： The experiment was carried out in the brain research center of Southern Medical UniVersity between July and November 2004. Fourteen patients with depression and 36 healthy volunteers were selected from Nanfang Hospital of Southern Medical University. Three categories of stimuli were used： three Chinese words （happy, think, fear） pictures. Thus, these pictures were viewed 50 times in the total of 150 picture presentations. Subject＇s task was to press a key if the successive stimulus was the same. Subjects were instructed to respond as accurately and quickly as possible. The right and error rates were record by system.The spatiotemporal distribution of the wave of event related potential evoked by the pictures and the difference of ＂emotional-wave＂ between two groups was observed. RESULTS： One female subject and 1 male subject in the depression group and 3 female subjects and I male subject in the normal control group were excluded because of the great inference of electroencephalogram （EEG）, and finally 12 subjects in the depression group and 32 subjects in the normal control group were involved in the data analysis. ① The reaction time in the depression group was prolonged as compared with that in the normal control group [（734.08±86.87）, （654.40±94.99） ms, t=2.44, P 〈 0.05], the accuracy rate was decreased [（86.24±13.92）%, （92.32±4.79）%, t=2.11, P 〈 0.05], and the score of Zung self-rating depression scale （SDS） was higher [（51.50±8.95）, （33.7 ±6.53）, t=4,85, P 〈 0.001]. ② There was significant difference in the ＂emotion-wave＂ between the depression group and normal control group. The difference between positive emotion and neutral emotion （group A） and difference between negative emotion and neutral emotion （group B） were compared between the depression group and normal control group so as to investigate the changes of the difference of affeetive emotion and words of neutral emotion （＂emotion-wave＂）. In group A, the emotion-wave spread from right temple region to central region （80-100 ms）, occurred separately in right fronto-temporal region （120-140 ms）, spread from right temple region to left fronto-tempnral region （160-200 ms） region, from right frontal region to left tempo-occipital region （220-240 ms） region, and from right temple region to left fronto-temporal region （280-300 ms） region, and occurred separately in right frontal region （500 ms）. In group B, the emotion-wave occurred separately in right fronto-temporal region （160-200 ms） and left tempo-occipital region （240-260 ms）. region, shrink from left fronto-tempo-occipital region to frontal region （300-320 ms）, occurred separately in right tempo-occipital region （380-400 ms）, right frontal region （440-460 ms） and left tempo-occipital region （540 ms）. The general impression was that the difference in right brain region was more outstanding, and there was significant difference between the depression group and normal control group. CONCLUSION： Abnormal behavioral feature and cognitional functional disorder, and negative cognitive deviation existed in major depression. The findings provided electrophysiological evidence that dysfunction of left cerebral cortex occurred in depression group. The disorder of affective modulation illustrated that the structure of Chinese emotional words recognition was complicated and web model, The distribution of the structures involved in the modulation was extensive, not limited only in some independent cortex and nuclei such as prefrontal cortex and amygdaloid body. The disorder of hemisphere lateralization might be related with selective inhibition of functional integration in different prefrontal lobes area and stages, during appreciation and perception of emotional stimulus.