注意缺陷多动障碍与正常儿童汉字事件相关电位的比较

目的 通过对注意缺陷多动障碍(ADHD)儿童和正常儿童执行语义启动任务的认知电位的比较,探讨ADHD患儿汉字语义理解的神经机制.方法 选择ADHD患儿52例,正常对照组儿童45名.使用汉字语义启动任务(相关、不相关、假字组)分别对ADHD及正常儿童进行检测,BESA软件提取认知电位进行比较分析.结果 (1)行为学:不相关反应时间ADHD组为(1252±256)ms,长于正常对照组[(1131±194)ms,P<0.05].(2)事件相关电位(ERP)-N2:汉字相关任务Cz导联N2波幅ADHD组高于正常对照组[-7.7(-12.8,-5.0)μV比-5.6(-9.4,-3.2)μV,P<0.05].(3)ERP-P3:汉字不相关任务Cz导联P3波幅ADHD组低于正常对照组[5.4(2.0,9.5)μV比9.5(4.2,16.9)μV,P<0.01].结论 汉字相关ERP-N2和不相关ERP-P3波幅可成为监测ADHD汉字认知水平的量化指标,并能对ADHD的诊断及疗效的评估提供一定的帮助.

Event-related potentials in character semantic priming of attention deficit hyperactivity disorder children and normal children: a comparative study

Objective To investigate the cognitive event related potentials in Chinese character priming effect of children with attention deficit hyperactivity disorder (ADHD) and to analyze the neural mechanism of the priming effect. Methods Fifty-two ADHD children aged (9.5 ± 1.7 ) and 45 age-matched children without ADHD were asked to perform a Chinese character semantic priming task while electroencephalogram was recorded. During the Chinese character semantic priming task the subjects were instructed to judge whether the presented target word was a related word,unrelated word,or a pseudoword and event-related potentials (ERPs) were elicited and analyzed with the brain electricity source analysis (BESA) software. Results (1)The behavioral results showed that the reaction time to the unrelated character stimuli in the ADHD children was (1252±256) ms,significantly longer than that in the normal control [(1131±194) ms,P<0.05]. (2) The amplitude of the character related N2 at the Cz lead in the ADHD children was-7.7 (-12.8,-5.0) μV,significantly larger than that of the normal controls [-5.6 (-9.4,-3.2) μV,P <0.05]. (3) The amplitude of character unrelated stimuli P3 at the Cz lead of the ADHD children was 5.4 (2.0,9.5) μV,significantly lower than that of the normal control [ 9.5 (4.2,16.9) μV,P <0.01 ]. Conclusion There is a positive correlation between the amplitude of N2 and the difficulty in character semantic priming. It is more difficult for the ADHD children than normal controls to accomplish the same semantic task. ADHD children need more attention resources than normal controls. The amplitudes of character related-N2 and unrelated-P3 may become markers to measure the development of recognition in the ADHD children,thus being helpful in the ADHD diagnosis.