视觉工作记忆容量个体差异的事件相关电位时空模式研究

A study on spatio-temporal patterns of ERP of individual differences of visual working memory capacity

目的：探索视觉工作记忆（WM）的电生理变化特点，研究视觉WM容量限制个体差异及其可能机制。方法：采用延迟样本匹配任务观察18名受试者在不同刺激项目条件下诱发的事件相关电位（ERP）变化特点，ERP分析结果利用t值的统计参数影像呈现。结果：视觉WM高容量组在双侧后顶部和侧枕部所诱发的负向慢波的波幅随着刺激的项目数从2～4的增加其波幅有意义的增高，而低容量组变化不明显。时空模式显示两组差异的显著效应主要发生在顶枕区和额区。结论：视觉WM容量存在个体差异，其差异相关的脑功能区可能在顶枕部和额区。

Aim：To explore the electro-physiological changes of visual working memory （WM）and its possible mechanism of capacity limitation and individual differences.Methods：Delayed sample matching duty was used to observe the characteristics of ERP changes of 1 8 participants under the evoking of differ-ent types of stimuli items.The result of ERP analysis was presented by statistical parametric mapping （SPM）of t value.Results：A big negative slow wave in high-capacity group of visual WM was observed in bilateral posterior parietalis and lateral occipute,its amplitude increased gradually with the number of stimulus items increasing from 2 to 4 and it reached maximum at 4 items,but these changes in low capaci-ty group was not very obvious.Spatio-temporal patterns showed significant effects in parietal-occipital sites and frontal cortex.Conclusion：There are individual differences in limitation of visual WM capacity and functional sites of brain related to thier individual differences may located in parietal-occipital sites and frontal cortex.