额叶参与执行控制的ERP负荷效应

Frontal Involvement to Executive Control: Load Effects Reflected by ERPs

为了检测执行控制的激活脑区及其时间进程,测量了14名健康成人被试执行汉字1/2/3-back任务时的64导事件相关电位(ERPs)。1/2/3-back任务均在头皮前部诱发N360,从刺激消失250m s起至600m s左右结束,其波幅表现出随记忆负荷而增高的负荷效应。3-back任务N360源分析发现位于额叶等部位的高密度电流分布和偶极子,表明左右半球均参与执行控制,但左侧额叶具有相对的半球优势。

In order to explore the cerebral areas activated by 1/2/3-back tasks of Chinese characters and the time-course of executive control, the 64 channels event-related potentials （ERPs） of 14 normal adults were measured. N360 was elicited by 1/2/3-back tasks at prefrontal scalp. The duration of the N360 was from 250ms to 600ms after stimuli occurred. The peak-to-peak amplitude of the N360 increased with the memory load enhancement and showed load effects. High ER density current distributions and three dipoles located in the frontal lobe and other areas were found by source analysis to the N360 of 3-back tasks. Results suggest that both hemispheres involved in the executive control at different extents, but the left frontal lobe has a relative hemispherical dominance.