任务无关情绪刺激对工作记忆信息更新的影响:来自ERP的证据

任务无关的情绪刺激如何对工作记忆的信息更新过程产生影响还不清楚。本研究采用情绪N-back任务,结合事件相关电位技术调查情绪对工作记忆信息更新的影响。ERP结果显示,在0-back任务中,负性分心物诱发的P3显著小于中性分心物,表明其干扰了工作记忆信息更新过程;而在2-back任务中,负性分心物诱发的P3与中性分心物没有显著差异,表明其未对信息更新表现出干扰效应。该结果支持了情绪与认知加工的双竞争模型。

How the Task Irrelevant Emotional Stimulus affect the Information Refreshing of Working Memory: An ERP Study

Previous studies have shown that the effect of emotional distractor on information storage in Working Memory (WM). The activity of fronto-parietal cortex related to WM is reduced when task irrelevant emotional stimuli presented. Furthermore, the interference effect of acute stress on WM is modulated by the WM load, and this effect was showed on the P3 component. However, how the emotional distractor affects the central executive function, i.e., information refreshing, of WM is not clear. To this end, an emotional N-back task was conducted combine with EEG technique. In this task, the WM load and valence of emotional distractor was manipulated. Participants were performed a digital 2-back or 0-back. In the 0-back task, participants were asked to detect whether the current digit is “1” or not. In the 2-back task, participants were asked to detect whether the current digit is presented two positions back or not. The neutral or negative emotional picture was presented under the digit in each trial. The behavioral results showed that there is a significant main effect of WM load, the participant response faster in the 0-back task than in the 2-back task, and they made less error in the 0-back task than in the 2-back task. For the P3 component, we found significant main effect of WM load, the amplitude of P3 for the 0-back task were larger than for the 2-back task. Furthermore, in the 0-back task, negative distractor elicited smaller P3 than the neutral distractor. However, in the 2-back, the difference between negative and neutral distractor is not significant. These results can easily explain by the recently proposed dual competition model which positing that emotional and cognitive processes, when operating simultaneously, compete with each other for limited neural resources. Specifically, processing of emotional stimuli may interfere with ongoing cognitive processes when cognitive resources are not entirely devoted to goal-directed processing under a lower task demanding condition. In contrast, the interference effect is attenuated due to the suppression of emotional processing under a high task demanding condition.