情绪词汇认知加工诱发电位时空模式的脑功能研究

目的应用多通道事件相关电位(event-related potential,ERP)分析技术,探讨正常青年受试者对情绪性词汇认知加工脑神经功能电活动机制。方法应用不同情绪效价的情绪刺激图片对31例健康志愿者进行情绪效价5个水平情绪脑电诱发电位的测试判别,观察受试者对5个情绪效价水平情绪词汇的情绪反应。结果 ERPs统计参数映像图(SPM)结果,对词汇情绪性加工的显著性差异最早可见于刺激后60~200ms;中后期(刺激后420~960ms)极负性和中性情绪反应显著性差异表现为右腹侧记忆-注意整合网络出现刺激负荷效应。极正性和中性情绪反应差异为中期(刺激后320~420ms)的左顶、颞、枕,晚期(刺激后680~1 000ms)见到右额中央负荷效应。极正性和极负性情绪反应差异于刺激后400~1 000ms见于双侧眶额皮层、腹内侧前额皮层、前扣带回皮层和躯体感觉皮层等脑区的广泛记忆-注意整合网络引起更强的激活。结论个体认知行为差异和社会环境背景影响不同情绪效价情绪性词汇的加工,不同情绪效价的情绪性词汇加工过程中存在显著性差异。正负性情绪词汇的加工是双侧半球广泛脑区的记忆-注意整合网络激活效应,并存在脑的偏侧化激活效应。     

全面性发作癫痫患者的情绪词汇加工

目的比较全面性发作癫痫患者不同情绪效价词汇的加工情况,评估其是否存在情感认知功能损害。方法采用事件相关电位技术,研究全面性发作癫痫患者和正常人群3种不同情绪效价词汇刺激诱发情绪反应的差异。结果癫痫组与对照组在汉密尔顿抑郁量表得分、正确率、平均反应时比较差异均有统计学意义(P0.05),癫痫组负性情绪词汇刺激反应时最长。负性、中性、正性三种不同情绪效价刺激反应时组间比较差异有统计学意义(P0.05)。ERP的t检验统计参数映射:2组3种不同情绪效价在刺激后130~160ms双侧后颞区及枕极均可见显著差异。负性情绪刺激400~640ms的注意加工阶段,正性情绪刺激700~970ms进一步加工阶段,癫痫组与对照组比较差异有统计学意义(P0.05);中性刺激后310~950ms额极,前颞部区域,2组差异有统计学意义(P0.05)。结论全面性发作癫痫患者有伴发抑郁情绪障碍高风险,其情绪性词汇刺激行为效能降低,反应时显著延长,反应错误率增加。全面性发作癫痫患者存在明显情绪认知功能损害,其负性情绪认知严重受损,并且其视觉皮层的早期知觉加工也受到损害。     

汉字单字词识别的N400

目的　探讨单词识别过程中事件相关电位N40 0成分的心理学意义。方法　在长 ( 60 0ms)与短 ( 2 0 0ms)两种刺激呈现间隔 (SOA)、3种语境 (相关、中性和无关 )条件下 ,进行词汇抉择作业 ,通过对反应时间 (RT)和事件相关电位 (ERP)的检测 ,观察目标词词汇抉择的语义启动效应 (RT效应和N40 0波幅效应 )。结果　长SOA时 ,RT实验有语义促进效应 (相关语境RT较中性语境短 )和抑制效应 (无关语境RT较中性语境长 ) ,而ERP实验只有N40 0波幅抑制效应 ;短SOA时 ,RT实验只有语义促进效应 ,而ERP实验无任何N40 0波幅效应。结论　结果表明 ,N40 0反映了词汇后水平的整合加工 ,而不反映词汇水平的词汇提取加工。     

抑郁症患者汉语情绪词阈下的Stroop效应事件相关电位

背景：抑郁症患者负性认知偏差与情绪信息加工的关系是一个重要的研究课题。情绪Stroop测验常用于评估情绪加工特点,而情绪词阈下Stroop刺激模式也常用于精神病学临床研究。 目的：本研究采用阈下汉语情绪词Stroop刺激范式来探讨抑郁症患者异常情绪信息加工的事件相关电位(ERP)效应。 设计,时间和地点：随机对照设计,时间为2007年8月至2008年3月,地点在中南大学湘雅二医院。 研究对象：首发抑郁症患者26例,符合DSM-IV抑郁症诊断标准,无脑部疾病、躯体疾病,未进行电休克治疗和抗抑郁药物治疗。健康对照组24例。两组在年龄、性别和教育水平方面无差异,均为右利手。 方法：采用阈下汉语情绪词Stroop刺激范式,要求被试对呈现200ms的红色或蓝色方块进行反应,而汉语情绪词阈下启动刺激为20ms。主要分析行为学和ERP数据。 主要测试指标：反应时和ERP成分的潜伏期和波幅。参照ERP平均波幅图以及其它研究,主要分析N270 (220~300ms)成分和N400 (380~450ms)成分的潜伏期和波幅。 结果：行为数据显示两组正确率之间无显著性差异,抑郁症组反应时比正常对照组延长,尤其是负性词与中性词(p<0.01)。重复测量方差分析表明,N270成分的波幅有词性和电极的主效应(p<0.01)以及词性和电极的交互效应(p<0.05);两组波幅大小顺序均为正性词>负性词>中性词。组别、词性差异波地形图显示差异主要分布在额区和左侧顶颞区。N400成分的波幅有词性和电极的主效应(p<0.01),潜伏期显示电极的主效应(p<0.01)以及电极和组别的交互效应(p<0.01);两组波幅大小顺序均为正性词>负性词>中性词,而且两组之间的三种情绪词波幅之间有显著性差异(p<0.01)。组别、词性差异波地形图显示差异主要分布在左右额区、中央区和左侧顶颞区。 结论：抑郁症患者执行阈下汉语情绪词Stroop刺激作业时表现了异常的情绪信息加工特征,以及对汉语情绪词三种词性进行语义激活时与正常组相比表现为不同的ERP时程效应。研究结果支持我们提出的正负性情绪平行神经模型。     

抑郁症患者情绪图片刺激早期低频脑磁图研究

目的：探讨抑郁症患者给予视觉情绪图片刺激早期0～100ms、100～200ms、200～300ms3个时段8～30Hz的神经磁场激活特征。方法：8例抑郁症患者及12例健康右利手对照者,在给予国际情绪图片库（IAPS）正性、中性、负性情绪图片刺激同时记录脑磁图信号,使用SPM8b软件进行数据分析：设两样本t检验P〈0.01（未校正）和K值≥10个体素范围为差异有统计学意义。结果：与对照组相比,抑郁组在正性情绪图片刺激下,100～200ms内的左侧额下回,右侧的终板旁回、额内侧回、海马回激活增强。在中性情绪图片刺激下,抑郁组在0～100ms的右侧豆状核、岛叶、额上回,左内侧额叶,100～200ms内的右侧岛叶、豆状核壳核及屏状核,左侧额下回、额上回、颞上回,200～300ms内的右侧岛叶、豆状核、尾状核体激活增强。负性情绪图片刺激下抑郁组在0～100ms内的右侧颞上回、岛叶、尾状核头部、额中下回激活增强,100～200ms内的右侧额中回、尾状核体,200～300ms内右额下回激活增强。此外还比较一致的发现抑郁组在楔前叶、后扣带回等顶叶脑区激活降低。结论：抑郁个体起注意调节功能的顶叶脑区如楔前叶功能不足,对视觉皮质向前部脑区情绪信息颞叶底部传递通路抑制不足,腹侧前额皮质、岛叶过度的激活,可能是抑郁症的一个发病基础。     

缓解期抑郁障碍患者面孔情绪识别特征的研究

目的:探讨缓解期抑郁障碍患者面孔情绪识别的特点及与正常人的异同。方法:采用改编的情绪启动范式对缓解期抑郁障碍患者30例(研究组)和与其性别、年龄及文化程度相匹配的健康人30名(正常对照组)进行测试,分别对两组的反应时、错误率及判断一致程度进行分析并比较两组之间差异。结果:研究组靶刺激与线索词的9种组合平均反应时长于正常对照组(P均0.01);研究组对中性面孔情绪图片-悲伤(χ~2=14.652)、平淡(χ~2=4.837)和正性面孔情绪图片-快乐(χ~2=8.251)的错误率显著高于正常对照组(P0.05或P0.01);对正性面孔情绪图片-快乐(F=28.680)和中性面孔情绪图片-平淡(F=35.342)这两个组合一致性的判断程度低于正常对照组(P均0.001)。结论:缓解期抑郁障碍患者对正性和中性面孔情绪识别性低,且存在中性面孔情绪识别悲观偏倚的特点,但对负性面孔情绪的识别正常。     

抑郁症患者恐惧与中性面孔刺激的脑磁图研究

目的:利用脑磁图探讨抑郁症患者给予重复恐惧、中性面孔刺激后早期神经磁场激活特征。方法:8例抑郁症患者及12名健康右利手对照者,在给予恐惧、中性面孔图片刺激同时记录脑磁图信号,使用SPM8b软件进行数据分析;设两样t检验P<0.005(未校正)和K值≥40个体素范围为差异有统计学意义。结果:在0～50Hz频率范围内,与对照组相比,抑郁组在恐惧面孔图片刺激下显示出左侧眶额皮质、腹外侧前额皮质激活增强;在中性面孔刺激下,抑郁组显示出左侧腹外侧前额皮质和眶额皮质、左前扣带回激活增强,双侧顶叶如楔前叶等激活减弱。结论:抑郁症患者情绪感受脑区左侧前额皮质低频脑磁图功率增强。     

老年抑郁症患者面孔知觉早期加工的事件相关电位研究

目的 采用事件相关电位技术,探讨老年抑郁症患者面孔识别(区分面孔还是非面孔)和面孔结构信息早期加工的脑电生理机制.方法 被试者包括19例老年抑郁症患者(患者组)及17名健康老年人(对照组).要求被试者观看图片并计数蝴蝶(靶刺激)呈现次数,其他图片(包括面孔、非面孔)为非靶刺激.记录32导脑电波.结果 (1)患者组非靶刺激诱发的P＜,1＞[(3.9±0.8)μV]和N170波幅[(-10.1±1.1)μV]均低于对照组[P<,1>:(6.8±0.8)μV;N170:(-14.4±1.1)μV;P＜0.05～0.01];(2)患者组和对照组均产生显著的N170效应(Nd170)以及N170翻转效应(倒立面孔图像时的N170变化),但患者组右侧颢枕区的N170效应[(-5.8 4±0.9)μV]弱于对照组[(-8.8±0.9)μV,P＜0.05],翻转效应的组间差异则无统计学意义(P＞0.05);(3)患者组靶刺激的P＜,3＞潜伏期[(400 ±10)ms]长于对照组[(368±10)ms;P＜0.05].结论 老年抑郁症患者可能存在面孔基本水平(区分面孔还是非面孔)早期识别的损害,而对面孔结构信息的早期加工则保持相对完整.     

抑郁患者对情绪刺激的注意偏向及其大脑功能磁共振成像证据

目的 探讨抑郁患者的注意偏向及其大脑功能磁共振成像证据.方法 采用17项汉密尔顿抑郁评定量表( HRSD17)并结合中国精神障碍分类与诊断标准筛选被试,分为患者组(9例,HRSD17评分≥17分)、康复组(9例,7分≤HRSD17评分＜17分)和对照组(10名,HRSD17评分＜7分),采用情绪斯特鲁普范式和功能磁共振成像技术,考察抑郁症患者对情绪面孔刺激的注意偏向及其大脑功能磁共振成像证据.结果 (1)康复组在消极、积极及中性条件下对情绪面孔刺激的颜色命名反应时[(701.85± 180.70)、( 635.58±119.79)、(598.88±130.41)ms]短于患者组[(991.04±194.23)、(888.22±184.16)、(745.59±165.38) ms],2组比较差异有统计学意义(P＜0.05),但与对照组[(649.40±143.35)、(633.28±120.50)、(565.69 ±89.87)ms]的差异无统计学意义(P＞0.05);(2)在消极情绪面孔刺激下,康复组比患者组被激活更多的脑区,包括左右额上回和中回、右颞叶、左舌回和左枕叶等.结论 抑郁患者对负性刺激的注意偏向及其脑功能可能随临床康复进程获得改善.     

晚发抑郁症患者情绪面孔持续注意偏向的瞳孔监测研究

目的:研究晚发抑郁症(late-onset depression,LOD)患者早期、中期和持续注意偏向特点,探索抑郁症早期干预的潜在认知靶点。方法:以符合《国际疾病分类》第10版抑郁发作诊断标准的36例LOD患者为患者组,匹配27名正常志愿者为对照组。采用真人情绪面孔图片作为刺激材料,应用点探测任务范式进行实验,任务过程中测试瞳孔直径、注视方向和反应时间;情绪面孔呈现时间为200 ms与2 000 ms,瞳孔直径监测时间为11. 5 s。结果:患者组点探测任务中平均反应时长于对照组[(459. 6±104. 8) ms vs.(441. 3±112. 1) ms,F=4. 23,P 0. 05];延长刺激呈现时间被试整体反应时间缩短[(438. 5±93. 6) ms vs.(460. 2±123. 3) ms,F=22. 34,P 0. 01]。患者组对恐惧面孔首凝视点定向偏向分数显著小于对照组(F=8. 64,P 0. 01)。长呈现时间、一致试验后部分患者组比对照组瞳孔扩张更明显(F=5. 1,P 0. 05);短呈现时间、不一致试验后部分对照组比患者组的瞳孔扩张更明显(F=7. 63,P 0. 01)。结论:LOD患者存在持续的认知-感情负荷改变,导致较为固定的负性注意偏向。早期干预这些改变的靶点可能对避免或延缓抑郁症的发作与复发有重要的临床价值。     

Event-related potentials of recognizing happy and neutral faces

In event-related potentials (ERPs) studies, recognition memory is associated with two positivities: one over parietal regions, and one over frontal regions. With nameable neutral stimuli, such as words or common objects, the parietal effect is usually left lateralized, and the frontal effect is usually right lateralized. We investigated the lateralization of these effects for nonnameable emotional stimuli: unfamiliar faces with happy and neutral expressions. The parietal effect was bilateral, suggesting that the left lateralization of this effect in studies using nameable stimuli reflected verbal processing. The frontal effect was left lateralized for happy faces, but right lateralized for neutral faces. This finding is consistent with the valence hypothesis, which posits that processing of pleasant emotions is lateralized to the left hemisphere.     

Hemispheric processing of differently valenced and self-relevant attachment words in middle-aged married and separated individuals

The reliance in experimental psychology on testing undergraduate populations with relatively little life experience, and/or ambiguously valenced stimuli with varying degrees of self-relevance, may have contributed to inconsistent findings in the literature on the valence hypothesis. To control for these potential limitations, the current study assessed lateralised lexical decisions for positive and negative attachment words in 40 middle-aged male and female participants. Self-relevance was manipulated in two ways: by testing currently married compared with previously married individuals and by assessing self-relevance ratings individually for each word. Results replicated a left hemisphere advantage for lexical decisions and a processing advantage of emotional over neutral words but did not support the valence hypothesis. Positive attachment words yielded a processing advantage over neutral words in the right hemisphere, while emotional words (irrespective of valence) yielded a processing advantage over neutral words in the left hemisphere. Both self-relevance manipulations were unrelated to lateralised performance. The role of participant sex and age in emotion processing are discussed as potential modulators of the present findings.     

Frontal and posterior sources of event-related potentials in semantic comprehension

An important question in brain and language research is how activity in multiple brain networks is coordinated over time during semantic comprehension. To address this question, we applied spatiotemporal source analysis to event-related potentials (ERPs) recorded as subjects read words that were meaningful or incongruous in the context of a sentence (N400 paradigm). The incongruous word was placed either early in the sentence or at the end. Source analysis showed activity in language areas of the left hemisphere, right temporal cortex and medial limbic cortex. The initial detection of semantic incongruity (approximately 250 ms) engaged the left prefrontal cortex and left anterior cingulate. In the critical (300-500 ms) interval, regional sources in left and right lateral prefrontal cortex, right temporal cortex, and both anterior and posterior cingulate were responsive to the semantic manipulation. Left hemisphere activity preceded right hemisphere activity, and semantic effects in frontal regions began earlier and were more sustained than the transient effects within posterior cortical regions. Findings are discussed with respect to recent theories of corticothalamic and corticolimbic networks in attention and semantic processing.     

The influence of emotional associations on the neural correlates of semantic priming

Emotions influence our everyday life in several ways. With the present study, we wanted to examine the impact of emotional information on neural correlates of semantic priming, a well-established technique to investigate semantic processing. Stimuli were presented with a short SOA of 200 ms as subjects performed a lexical decision task during fMRI measurement. Seven experimental conditions were compared: positive/negative/neutral related, positive/negative/neutral unrelated, nonwords (all words were nouns). Behavioral data revealed a valence specific semantic priming effect (i.e., unrelated > related) only for neutral and positive related word pairs. On a neural level, the comparison of emotional over neutral relations showed activation in left anterior medial frontal cortex, superior frontal gyrus, and posterior cingulate. Interactions for the different relations were located in left anterior part of the medial frontal cortex, cingulate regions, and right hippocampus (positive > neutral + negative) and left posterior part of medial frontal cortex (negative > neutral + positive). The results showed that emotional information have an influence on semantic association processes. While positive and neutral information seem to share a semantic network, negative relations might induce compensatory mechanisms that inhibit the spread of activation between related concepts. The neural correlates highlighted a distributed neural network, primarily involving attention, memory and emotion related processing areas in medial fronto-parietal cortices. The differentiation between anterior (positive) and posterior part (negative) of the medial frontal cortex was linked to the type of affective manipulation with more cognitive demands being involved in the automatic processing of negative information.     

A transfer appropriate processing approach to investigating implicit memory for emotional words in the cerebral hemispheres

Forty undergraduate students participated in two experiments designed to investigate the impact of perceptual and conceptual encoding manipulations on implicit memory for emotional words in each cerebral hemisphere. Adopting a transfer appropriate processing approach, the encoding manipulations were designed to promote processing of the surface features of stimuli in Experiment 1, and their semantic meaning in Experiment 2. In both experiments, participants completed the designated encoding task, followed by a lexical decision task where primed and unprimed words were presented to the left (LVF) and right visual fields (RVF). In Experiment 1, implicit memory was observed for RVF presentations of words primed according to their perceptual features. Word valence did not impact on visual field of presentation for primed or unprimed words. In Experiment 2, participation in the conceptual encoding task differentially impacted on processing and implicit memory for emotional words presented in the LVF, where priming the conceptual meaning of words facilitated the processing of positive, relative to negative and non-emotional words. In addition, implicit memory for conceptually primed negative words was reflected in inhibition of primed relative to unprimed negatively valenced words presented in the LVF. In contrast, for RVF presentations, there was evidence of implicit memory for conceptually primed non-emotional words, but not for emotional words. The results are generally consistent with the right hemisphere model of emotion, which posits greater right hemisphere involvement in both the processing and implicit memory of emotional stimuli. The results also support Nagae and Moscovitch's suggestion [Nagae, S., & Moscovitch, M. (2002). Cerebral hemispheric differences in memory of emotional and non-emotional words in normal individuals. Neuropsychologia, 40, 1601-1607] that level of processing be incorporated into studies examining the veracity of the right hemisphere and valence models of emotional processing. The study demonstrated the usefulness of adopting a transfer appropriate processing approach to investigating memory for word valence in each hemisphere.     

The time course of semantic category processing in the cerebral hemispheres: an electrophysiological study

Using visual half-field presentations of words to the right (RVF) and to the left visual field (LVF), this study investigated the time course of the hemispheric involvement in the processing of semantic category information. Multi-channel event related brain potentials (ERPs) were recorded from 15 healthy subjects during a categorisation task of sequentially presented word pairs. Subjects had to judge mentally after the appearance of the second word whether the words of a pair were semantically related (SR) or not (SU). ERPs were computed, from 100 ms before the onset of the second word to 600 ms, for SR and SU conditions in the LVF and in the RVF separately. The temporal segmentation of ERP map series into sequences of quasi-stable map configurations revealed a total of seven segments in each visual field of which only the first five (S1-S5, appearing between 70 and 400 ms) showed different map configurations as a function of visual field but presented a similar temporal sequence in both visual fields. By contrast, of the last two segments (S6 and S7) which appeared between approximately 400 and approximately 600 ms, only S7 differentiated SR and SU conditions in terms of its duration. Source localisation analysis of the segments showed that following the initial activation of posterior brain regions as a function of the visual field of presentation, a common neural network was activated in the left hemisphere (LH) although the dynamics of activation varied as a function of visual field. Concerning the role of the right hemisphere (RH) in lexico-semantic processing, the results presented here appear to be compatible with a 'callosal relay model' and suggest that, in healthy subjects, information is transferred rapidly ( approximately 150 ms) from the RH to the language dominant-LH.     

Neurophysiological evidence of cognitive inhibition anomalies in persons with major depressive disorder

ObjectiveThe neural correlates of inhibitory deficits for emotional semantic material in persons with major depressive disorder (MDD) were investigated.MethodsIndividuals (n = 15) with a diagnosis of MDD or MDD in partial remission, and healthy controls (n = 14) underwent recording of event-related brain potentials (ERPs) while performing a computerized emotional Stroop task.ResultsThere were no group performance differences on the emotional Stroop task. However, the analysis of ERP waveforms revealed a larger negative wave peaking at about 170 ms over the left than the right hemisphere only in controls; a negative displacement (N450) at parietal sites for positive and negative words only for persons with MDD; in both groups, processing negative and positive words was associated with a positive displacement that peaked at about 450 ms and was larger over the left lateral frontal region; and, the N450 modulation correlated with negative automatic thinking and depressive symptoms.ConclusionsThe electrophysiological data reveal early changes in neural activity associated with word processing as well as valence-related changes in the N450 component at parietal sites in MDD.SignificanceThis valence-related increase in N450 amplitude at parietal sites may reflect an automatic capture of attention by words with emotional valence.     

ERP evidence for a sex-specific Stroop effect in emotional speech

The present study investigated the interaction of emotional prosody and word valence during emotional comprehension in men and women. In a prosody-word interference task, participants listened to positive, neutral, and negative words that were spoken with a happy, neutral, and angry prosody. Participants were asked to rate word valence while ignoring emotional prosody, or vice versa. Congruent stimuli were responded faster and more accurately as compared to incongruent emotional stimuli. This behavioral effect was more salient for the word valence task than for the prosodic task and was comparable between men and women. The event-related potentials (ERPs) revealed a smaller N400 amplitude for congruent as compared to emotionally incongruent stimuli. This ERP effect, however, was significant only for the word valence judgment and only for female listeners. The present data suggest that the word valence judgment was more difficult and more easily influenced by task-irrelevant emotional information than the prosodic task in both men and women. Furthermore, although emotional prosody and word valence may have a similar influence on an emotional judgment in both sexes, ERPs indicate sex differences in the underlying processing. Women, but not men, show an interaction between prosody and word valence during a semantic processing stage.     

Processing words with emotional connotation: an FMRI study of time course and laterality in rostral frontal and retrosplenial cortices

Responses of rostral frontal and retrosplenial cortices to the emotional significance of words were measured using functional magnetic resonance imaging (fMRI). Twenty-six strongly right-handed participants engaged in a language task that alternated between silent word generation to categories with positive, negative, or neutral emotional connotation and a baseline task of silent repetition of emotionally neutral words. Activation uniquely associated with word generation to categories with positive or negative versus neutral emotional connotation occurred bilaterally in rostral frontal and retrosplenial cortices. Furthermore, the time courses of activity in these areas differed, indicating that they subserve different functions in processing the emotional connotation of words. Namely, the retrosplenial cortex appears to be involved in evaluating the emotional salience of information from external sources, whereas the rostral frontal cortex also plays a role in internal generation of words with emotional connotation. In both areas, activity associated with positive or negative emotional connotation was more extensive in the left hemisphere than the right, regardless of valence, presumably due to the language demands of word generation. The present findings localize specific areas in the brain that are involved in processing emotional meaning of words within the brain's distributed semantic system. In addition, time course analysis reveals diverging mechanisms in anterior and posterior cortical areas during processing of words with emotional significance.