线索突出性强化前瞻记忆监控及任务切换的事件相关电位研究

目的 通过考察前瞻干扰效应的神经相关,探讨前瞻记忆提取机制.方法 进行中任务为判断两幅先后呈现的模式图片是否相同,前瞻记忆任务为检测2种线索突出性不同的模式图片,2种突出性线索图片分别与进行中任务刺激混编为2组,单纯执行进行中任务为对照组.每个被试均接受上述3组测试.观察指标为行为数据及19通道事件相关电位.结果 行为绩效未发现显著的任务干扰效应反应时:对照组(750.29±161.33)ms,高突出组(770.94±174.89)ms,低突出组(764.79±174.12)ms,F(1.52,25.82)=0.48,P =0.57;正确率:对照组(85.89±8.07)%,高突出组(88.26±7.00)%,低突出组(87.91±7.28)%,F(1.50,25.57)=2.46,P =0.12].混编了2种突出性线索的进行中任务出现显著双侧额叶事件相关电位效应(160～240 ms),高突出线索导致右前额区出现显著事件相关电位效应(360～440 ms).结论 前瞻记忆提取以策略监控为基础,高突出性线索不仅强化前瞻记忆任务的目标保持,而且促进两类任务的切换.

Salient cues enhance strategy monitoring and task switching for prospective memory:An ERP study

Objective To investigate the retrieval mechanism of prospective memory,spatiotemporal patterns of event-related potentials (ERP) were used to reveal neural correlates of the prospective interference effect. Methods A task of matching two sequential patterns was taken as the ongoing task and the detection of patterns with two salient levels as prospective memory tasks. Experiments were performed in blocks for single ongoing task block and two prospective memory blocks. Results No significant behavioral effect was found for prospective interference reaction time(ms):control blocks 750.29±161.33,high salience blocks 770.94±174.89,low salience bocks 764.79±174.12,F(1.52,25.82)=0.48,P =0.57 and correction rate(%):control blocks 85.89±8.07,high salience blocks 88.26±7.00,low salience blocks 87.91±7.28,F(1.50,25.57)=2.46,P =0.12].But significant ERP effect was found at bilateral frontal regions from 160 ms to 240 ms for both two prospective memory blocks. Moreover,greater negativity at the right frontal polar region appeared significantly at 360'440 ms for higher salient patterns. Conclusion Prospective memory is retrieved based on strategic monitoring and high salient stimuli may enhance to keep the prospective goal and improve task switching.