脑卒中患者面孔表情识别的神经电生理机制

目的:探讨脑卒中患者面孔表情识别的神经电生理机制。方法:采用简笔画正性、中性、负性表情面孔图片作为刺激物,用事件相关电位(ERP)记录仪记录25例正常人和19例脑卒中患者表情面孔隐含识别的ERP,t检验数值采用统计参数映像呈现。结果:脑卒中组对三种表情的反应时间为742.01±205.58ms,正确率为86.14%±10.06%;对照组的反应时间为678.93±150.88ms,正确率94.69%±6.17%。脑卒中组与正常对照组相比,反应操作正确率显著降低;统计参数映像结果显示,在面孔加工的早期阶段,即N170时段内的ERP成份波幅显著降低。结论:脑卒中患者在面孔表情早期加工阶段即出现异常。     

头皮针对脑卒中康复期患者认知与运动功能障碍疗效观察

目的观察头皮针治疗对脑卒中康复期患者认知功能与运动功能障碍的疗效。方法将80例有认知障碍的脑卒中康复期患者随机分为头针组（n=41）和对照组（n=39）。两组患者均予神经内科常规治疗及康复训练,头针组在此基础上进行头皮针治疗。治疗前及治疗3个月后采用事件相关电位P300潜伏期和波幅测定、Fugl-Meyer运动功能积分（FMA）、Barthel指数（BI）,分别对患者进行认知功能、运动功能和日常生活活动（ADL）能力评定。结果治疗后,P300潜伏期头针组平均缩短38ms,对照组平均缩短17ms,头针组改善幅度优于对照组（P〈0.05）;FMA及BI评分头针组改善幅度亦优于对照组（P〈0.05）。结论头皮针能有效改善脑卒中康复期患者的认知功能,促进运动功能和ADL能力的恢复。     

刺激相关冲突与任务相关冲突在脑内的并行处理

目的探讨大脑对刺激相关和任务相关冲突的处理机制。方法受试者分别默数数值相同和不同的数字对出现的次数,并记录头皮事件相关电位。数字对分为4种情况没有冲突、刺激相关冲突、任务相关冲突、刺激相关和任务相关双重冲突。结果3种冲突的数字对在第2个数字后引起事件相关电位N270,没有冲突的数字对则无该负波。N270的起始潜伏期终止时间在3种冲突之间没有显著差异。结论大脑并行处理刺激相关和任务相关冲突。     

学龄前儿童与成人汉语听觉失匹配反应的特征比较

目的考察学龄前儿童与成人汉语听觉失匹配反应(MMR)的特点。方法9 名学龄前健听儿童与8 名健听成人采用被动Oddball 模式进行事件相关电位测试,刺激为/bal/、/pal/辅音对。结果所有被试均诱发出明显MMR,成人表现为典型失匹配负波,学龄前儿童表现为宽大正向位移,出现的时间较晚,振幅较大。多因素方差分析显示,组别的主效应显著,学龄前儿童的MMR潜伏期长于成人,振幅大于成人(P<0.05)。结论获得了3~6 岁儿童和成人较为稳定、各具特点的MMR波形和指标值。     

Spatiotemporal Dynamics of Covert Attention With Different Degrees of Central Visual Field Defects: An ERP and sLORETA Study

PurposeThe present study aimed to investigate the spatiotemporal dynamics of covert attention by simulating different degrees of central visual field defects in healthy subjects.MethodsAn electroencephalogram (EEG) was recorded while 40 normal-sighted subjects performed a target discrimination task. Target stimuli simulated different defect degrees of the central visual field by artificially central scotomas (5, 10, 20, and 30 degrees of visual angle) masked on the center of black-and-white checkerboards. Event-related potentials (ERPs) and standardized low-resolution brain electromagnetic tomography (sLORETA) based on ERPs were analyzed.ResultsERP results indicated that during early perceptual processes, compared with 5-degree and 10-degree defects, N1 amplitudes of 20-degree and 30-degree defects decreased, whereas P2 amplitudes significantly reduced in 30-degree defects. During later discrimination and decision processing, N2 amplitudes gradually increased from 5-degree to 30-degree defects, whereas P3 amplitudes gradually decreased. Source localization indicated that 5-degree and 10-degree defects had stronger activations than 20-degree and 30-degree defects from the occipital cortex to the ventral stream and dorsal streams. Especially, 30-degree defects primarily recruited additional activations in the ventrolateral prefrontal cortex and ventral stream and later caused the disconnection of dorsolateral prefrontal-posterior parietal cortices in the dorsal stream.ConclusionsDifferent degrees of central visual field defects differed in distinct spatiotemporal characteristics at multiple stages of covert attention, from top-down forward feedback and attentional allocation to executive controls through ventral and dorsal processing streams, suggesting that the combination of ERP and source localization can reveal the spatiotemporal control capacity of the cortex on central visual field defects.     

Auditory event-related potentials during stage 2 NREM sleep in humans

SUMMARY  Event-related potential (ERP) recordings were used to investigate the nature of auditory stimulus evaluation during stage 2 sleep. Frequent and rare stimuli, differing in intensity and frequency, were presented to six adult subjects while awake and asleep. The latency and voltage distribution of one of the long-latency components evoked during sleep resembled the P3 component evoked while awake. However, it was attenuated in voltage and superimposed on N3, a large late negative component, most probably the slow potential of the K complex. The identification of a P3-like potential during sleep suggests that the P3 potential is not solely a marker of active cognitive processes, but contains a small component which reflects automatic, pre-attentive evaluation of deviant stimuli.     

年轻吸烟者对错误反应影响的事件相关电位研究

目的:通过事件相关电位技术和Eriksen Flanker任务的结合,探讨青少年吸烟者的认知控制能力是否存在异常。方法:采用被试者包括吸烟者19名(n=19),以及年龄、性别、受教育年限等与之相匹配的健康非吸烟者19名(n=19),比较两组的错误相关成分错误正波及其行为学任务表现。结果:与健康非吸烟者相比,吸烟组的错误数明显增加(F=5.133,P=0.030)。同时,青少年吸烟者的错误正波Pe的波幅有明显降低(P<0.001)。结论:青少年吸烟者存在错误处理缺陷,错误处理能力的降低可能与吸烟有关。     

Human movement-related potentials vs desynchronization of EEG alpha rhythm: a high-resolution EEG study

Movement-related potentials (MRPs) and event-related desynchronization (ERD) of alpha rhythm were investigated with an advanced high-resolution electroencephalographic technology (128 channels, surface Laplacian estimate, realistic head modeling). The working hypothesis was that MRPs and alpha ERD reflect different aspects of sensorimotor cortical processes. Both MRPs and alpha ERD modeled the responses of primary sensorimotor (M1-S1), supplementary motor (SMA), and posterior parietal (PP, area 5) areas during the preparation and execution of unilateral finger movements. Maximum responses were modeled in the contralateral M1-S1 during both preparation and execution of the movement. The SMA and PP responses were modeled mainly from the MRPs and alpha ERD, respectively. The modeled ipsilateral M1-S1 responses were larger and stronger in the alpha ERD than MRPs. These results may suggest that alpha ERD reflects changes in the background oscillatory activity in wide cortical sensorimotor areas, whereas MRPs represent mainly increased, task-specific responses of SMA and contralateral M1-S1.     

伴有中央颞区棘波的良性癫痫患儿认知功能事件相关电位研究

目的研究伴有中央颞区棘波的儿童良性癫痫(BCECTS)患儿是否存在认知功能损害以及探讨评价认知功能损害的的敏感指标。方法21例BCECTS儿童作为患者组,与其年龄、性别、受教育程度及家庭社会经济状况匹配的健康对照21名。成对的个位数字(S1和S2)依次呈现,要求受试者判断两个数字相同或不同。同步记录事件相关电位。结果两组在两个数字数值不同时都可以诱发出冲突负波N270。患者组N270的峰潜伏期均较对照组延长,波幅下降,而患者组P300的潜伏期及波幅与对照组无显著性差异。结论BCECTS儿童存在认知功能的损害。N270在评价轻度认知功能损害方面,敏感性高于P300。     

丘脑梗死听觉事件相关电位的研究

目的：研究丘脑梗死患者听觉事件相关电位（P300）的变化特点。方法：应用听觉事件相关电位和认知能力筛查量表检测丘脑梗死患者加例（患者组）和健康查体者30例（正常对照组）。结果：患者组P300波潜伏期明显延长（P〈0．01）;P300波波幅降低（P〈0．05），认知能力筛查量表评分也明显下降（P〈0．01）。左侧与右侧丘脑梗死P300波潜伏期、波幅和认知能力检查评分比较差异无统计学意义（P〉0．05）。治疗后随访P300波潜伏期、波幅和认知能力检查评分明显好转，与治疗前比较差异有统计学意义（P〈0．05或P〈0．01）。结论：听觉事件相关电位的检查有利于丘脑梗死认知功能状态的判断及病情变化的观察。