A Psychophysiological Study on the role of working memory in a visual search

我们记录了视觉搜索、记忆搜索和心理旋转任务中的事件相关电位（ERP），并观察到一些ERP变化，这些变化反映了工作记忆中言语、视觉和空间信息的加工。(1)在字母搜索任务中，视觉项目的增加导致至少两种负性的增加，这可以通过潜伏期、地形图和对目标刺激的敏感性来区分。(2)在延迟匹配样本任务中，对同一物理刺激的视觉ERP受记忆负荷的影响不同，这取决于S1-S2间隔中保存的信息类型（颜色、形状或位置）。(3)同步心算任务选择性地影响视觉/记忆搜索任务中对记忆负荷敏感的ERPs的幅值和地形图。由于显示负载引起的ERP变化不受此并发任务的影响。(4)同时进行无意义音节的复述和记忆搜索任务，可引起听觉词的N1波幅降低和ERPs的记忆负荷效应，但不影响视觉词和视觉图像的ERPs。(5)在心理旋转任务中，刺激角度引起的ERP负性增强受无意义形状的同时记忆任务的影响，但不受无意义音节记忆的影响。这表明事件相关电位的时间和空间分布可以作为子系统运行的指标（言语的、视觉的和空间的）在工作记忆中的作用，并且双任务方法是用于解开重叠成分的有用方法，用于推断这些电生理测量与工作记忆中涉及的过程之间的关联，以及用于估计工作记忆的多个子系统在各种认知任务中的作用和功能组织。

We recorded the event-related potentials (ERPs) in the visual search, memory search, and mental rotation tasks, and observed a number of ERP changes, which reflected the processing of verbal, visual, and spatial information in a working memory. (1) The increase of visual items to be processed in a letter search task caused the increase of at lease two kinds of negativities, which can be differentiated by latency, topography, and sensitivity to how a target stimulus was designated. (2) In a delayed matching to sample task, the visual ERPs to the physically same stimulus differently influenced by memory load, depending on the kind of information (color, shape, or location) held in S1-S2 interval. (3) A concurrent mental arithmetic task selectively affected the amplitude and topography of the ERPs sensitive to memory load in the visual/memory search task. The ERP changes due to display load were not affected by this concurrent task. (4) Rehearsal of nonsense syllable performed concurrently with memory search task caused the decrease of N1 amplitude and the memory load effect of ERPs to auditory words, but did not affect ERPs to visual words or visual images. (5) The negative enhancement of ERPs due to stimulus angle in a mental rotation task was affected by a concurrent memory task for nonsense shapes, but not by memory for nonsense syllables. These suggest that the temporal and spatial patterns of ERPs can be indices of the operations of subsystems (verbal, visual, and spatial) in a working memory, and that the dual task approach is a useful method for disentangling the overlapping components, for inferring association between these electrophysiological measures and the processes involved in a working memory, and for estimating the roles and functional organization of multiple subsystems of working memory in various cognitive tasks.