空间注意易化客体工作记忆的事件相关电位研究

目的 考察注意对位置、客体特征及两者绑定的工作记忆的影响.方法 记录16名受试者从事延迟匹配样本任务时的事件相关电位(event-related potentials,ERP),应用单因素三水平(任务:单纯位置,单纯颜色,两者绑定)重复测量析因设计.结果 工作记忆容量的任务效应显著F(1.95,29.23)=52.72,P =0.00],从大到小顺序为:位置(3.258±0.610)个、绑定(2.300±0.735)个和颜色(1.298±0.520)个.ERP的F值参数映像显示任务效应出现在两个时段:固化期(400～550 ms,额中央顶区)和维持期(700～1100 ms,双腹外侧额-顶区);后者进一步的t值参数映像提示颜色激活双腹外侧额区,位置激活后顶区,绑定激活两者.结论 空间注意分别在工作记忆的固化期通过选择编码、在维持期通过空间复述易化了客体工作记忆.

Spatial attention facilitates object working memory:An ERP study

Objective To investigate the impact of attention on location,object and location-object working memory. Methods Event-related potentials (ERP) were recorded from 16 healthy subjects while performing tasks of the color-only,the location-only and the color-location binding memory separately. A repeated-measures factorial design was adopted with three levels (tasks:the color,the location,the binding). Results Significant differences of working memory capacity were found among tasks F(1.95,29.23)=52.72,P =0.00] and listed in a decreasing order as:the location (3.258±0.610),the binding (2.300±0.735) and the color (1.298±0.520). Spatiotemporal patterns of the statistical parametric mapping (SPM) of F-value showed the task effect occurred during two stages:the consolidation stage (400'550 ms) in the frontal-central-parietal network and the maintenance stage (700'1100 ms) in bilateral ventral frontal-parietal regions. Spatiotemporal patterns of SPM(t) showed the significant differences between the color and the binding located at posterior parietal cortex during maintenance stage. Conclusion Spatial attention probably facilitates object working memory during both the consolidation stage by selective encoding and the maintenance stage by attention-based rehearsal mechanism.