Centre for Psychophysics, Psychophysiology, and Psychopharmacology, University of Wollongong, Wollongong, NSW 2522, Australia; Brain & Behaviour Research Institute, University of Wollongong, Wollongong, NSW 2522, Australia; School of Psychology, University of Wollongong, Wollongong, NSW 2522, Australia.
Int J Psychophysiol. 2013 Sep;89(3):399-408. doi: 10.1016/j.ijpsycho.2013.07.011. Epub 2013 Aug 6.
It has been suggested that the P300 component of the ERP is an electrophysiological index of memory-updating processes associated with task-relevant stimuli. Component magnitude varies with the time separating target stimuli (target-to-target interval: TTI), with longer TTIs eliciting larger P300 amplitudes. According to the template-update perspective, TTI effects observable in the P300 reflect the updating of stimulus-templates in working memory (WM). The current study explored whether young adults' memory-task ability could predict TTI effects in P300. EEG activity was recorded from 50 university students (aged 18-25 years) while they completed an auditory equiprobable Go/NoGo task with manipulations of TTIs. Participants also completed a CogState® battery and were sorted according to their WM score. ERPs were analysed using a temporal PCA. Two P300 components, P3b and the Slow Wave, were found to linearly increase in amplitude to longer TTIs. This TTI effect differed between groups only for the P3b component: The high WM group showed a steeper increase in P3b amplitude with TTI than the low WM group. These results suggest that TTI effects in P300 are directly related to WM processes.
有人认为，ERP 的 P300 成分是与任务相关刺激相关的记忆更新过程的电生理指标。分量大小随目标刺激之间的时间（目标-目标间隔：TTI）而变化，较长的 TTI 会引起更大的 P300 幅度。根据模板更新的观点，P300 中可观察到的 TTI 效应反映了工作记忆 (WM) 中刺激模板的更新。本研究探讨了年轻人的记忆任务能力是否可以预测 P300 中的 TTI 效应。在 50 名大学生（年龄 18-25 岁）完成听觉等概率 Go/NoGo 任务时，记录了他们的 EEG 活动，该任务对 TTI 进行了操作。参与者还完成了 CogState® 电池测试，并根据他们的 WM 分数进行了分类。使用时间 PCA 分析了 ERP。发现两个 P300 成分，P3b 和慢波，随 TTI 的延长呈线性增加幅度。这种 TTI 效应仅在 P3b 成分上在组间有所不同：高 WM 组的 P3b 幅度随 TTI 的增加比低 WM 组更陡峭。这些结果表明，P300 中的 TTI 效应与 WM 过程直接相关。
