作　　者： (曹园）; (周曙）; (王优）;

机构地区： 南方医科大学南方医院神经内科,广东广州510515

出　　处： 《南方医科大学学报》 2017年第6期755-760,共6页

摘　　要： 目的探索认知灵活性相关脑网络的动态演化。方法采用交替切换任务范式,23名被试完成数字大小和奇偶判断任务,每3个试次数字颜色改变,提示任务规则切换,3个试次分别对应切换、基线和准备条件。分析3种条件下的行为绩效和19通道事件相关电位统计参数映像的时空模式。结果切换代价(切换-基线)显著:反应时123.61±83.84 ms;正确率(1.24±3.30)%。事件相关电位统计参数映像(t)显示:切换效应先后出现在额顶网络的右侧和左侧部分,准备效应主要表现为反应前右侧额极和反应后左侧额极的激活。结论认知灵活性主要依赖于额顶网络的动态激活,而前额极参与任务切换前的跨试次准备过程;背侧额区参与试次内的即时任务切换,且左右两侧额区功能不同。 Objective To explore the neural dynamics during alternating task switching. Methods In an alternating-runs paradigm, 23 healthy volunteers were asked to categorize Arabic numerals displayed on the screen into either even or odd numbers or judge if the number was greater than 5 according its color cues. The color of the numerals were regularly switched every three trials （switch, nested and pre-switch trials）. ANOVA of repeated-measure and paired t-test were used for analysis of the behavioral performance and event-related potential （ERP） data of 19 channels, and statistical parametric mapping of F and t values was used to reveal the spatiotemporal patterns of ERP. Results Significant switch costs （switch versus nested trial） were found in the mean reaction time （123.61 ＆#177; 83.84 ms, P〈0.05） and the mean accuracy [（1.24 ＆#177; 3.30）%, P〈0.05]. Statistical parametric mapping of t value of ERP suggested that the switch effects appeared in the right frontal-parietal network and then in the left one. The preparation effects appeared in the right frontal pole followed by the left one, both accompanied by the activation of the posterior regions. Conclusions Cognitive flexibility depends on the dynamic activation of the fronto-parietal network. The frontal poles are involved in the pre-switch preparatory process, the dorsal frontal areas are related with the actual switch process, and the left and right frontal regions play different roles.

关 键 词： 认知灵活性 交替切换 事件相关电位 切换代价 准备效应