儿童事件相关电位N270—头皮电位分布特点及与成人的比较

目的：比较儿童与成人脑内冲突事件相关电位N270及头皮电位分布的特点,探讨冲突监测系统的发育过程。方法：20名健康学龄儿童和30名健康成人自愿者为受试者,儿童和成人分别分成两个组,其中一组人判断连续出现的对数字的颜色是否相同,不考虑数值（注意颜色组）。另一组人判断连续出现的一对数字的数值是否相同,不考虑颜色（注意数值组）,同时在头皮记录事件相关电位。结果：成人在刺激在发生冲突时,（颜色不同和／或数值不同）,无论在注意和不注意的状态下均可在第二个刺激出现后270ms左右引出事件相关电位N270,且分布在全头部;儿童只有被注意的刺激对的特征发生冲突时才能引出N270,注意颜色任务颜色冲突时,引出的N270分布在全头部,最高的波幅在中央和额部,注意数值任务数值冲突时,引出的N270主要分布左头中央和额部,结论：学龄儿童确实存在着冲突事件相关电位N270,其产生受注意的控制,其头皮电位的分布特点受所注意的刺激特征的影响,而成人N270的产生与注意无关,其头皮电位的分布与刺激特征无关。

Event-related potential N270 in adults and school age children

Objective:To compare the event-related potential N2 70 and its scalp distribution in adults and children and to explore the developmen t of the conflict monitoring system in brain.Methods:Thirty health a dults and twenty children participated in matching-to-sample task.They were sep ar ately divided into two subgroups.One subgroup was required to attend to the col o r of a pair of digits,but ignoring the magnitude.To the contrary,another subgro u p was required to focus on the magnitude while ignoring color.Subjects were ask e d to press one of the two buttons according to whether the two digits were ident ical in the attended attribute and event-related potentials were recorded on the i r scalps.Results:Any conflict in stimulus attributes,attended or un a ttended,elicited an event-related potential component around 270 ms after the on set of the sample stimulus in adults,which distributes on all of the scalp.In c h ildren N270 was only elicited when the attended stimulus attributes were in conf lict.The distribution of N270 is on all of the scalp when attending to the colo r of the pair digit and on the left-hemisphere when attending to the magnitude.Conclusion:In school age children,event-related potential N270 is prod uced under the control of attention.Its scalp distribution is different in vari ous stimulus attributes.