Melbourne Neuropsychiatry Centre, Department of Psychiatry, The University of Melbourne and Melbourne Health, Australia.
Neuropsychologia. 2011 Jan;49(1):92-102. doi: 10.1016/j.neuropsychologia.2010.10.021. Epub 2010 Oct 23.
Increasing evidence suggests that working memory and perceptual processes are dynamically interrelated due to modulating activity in overlapping brain networks. However, the direct influence of working memory on the spatio-temporal brain dynamics of behaviorally relevant intervening information remains unclear. To investigate this issue, subjects performed a visual proximity grid perception task under three different visual-spatial working memory (VSWM) load conditions. VSWM load was manipulated by asking subjects to memorize the spatial locations of 6 or 3 disks. The grid was always presented between the encoding and recognition of the disk pattern. As a baseline condition, grid stimuli were presented without a VSWM context. VSWM load altered both perceptual performance and neural networks active during intervening grid encoding. Participants performed faster and more accurately on a challenging perceptual task under high VSWM load as compared to the low load and the baseline condition. Visual evoked potential (VEP) analyses identified changes in the configuration of the underlying sources in one particular period occurring 160-190 ms post-stimulus onset. Source analyses further showed an occipito-parietal down-regulation concurrent to the increased involvement of temporal and frontal resources in the high VSWM context. Together, these data suggest that cognitive control mechanisms supporting working memory may selectively enhance concurrent visual processing related to an independent goal. More broadly, our findings are in line with theoretical models implicating the engagement of frontal regions in synchronizing and optimizing mnemonic and perceptual resources towards multiple goals.
越来越多的证据表明，工作记忆和知觉过程由于重叠脑网络中调节活动而动态相关。然而，工作记忆对与行为相关的干预信息的时空脑动力学的直接影响尚不清楚。为了研究这个问题，被试在三种不同的视觉空间工作记忆（VSWM）负荷条件下进行了视觉接近网格感知任务。通过要求被试记住 6 个或 3 个磁盘的空间位置来操纵 VSWM 负荷。网格总是在磁盘模式的编码和识别之间呈现。作为基线条件，在没有 VSWM 背景的情况下呈现网格刺激。VSWM 负荷改变了在干预网格编码过程中活跃的知觉表现和神经网络。与低负荷和基线条件相比，被试在高 VSWM 负荷下执行具有挑战性的感知任务时速度更快，准确性更高。视觉诱发电位（VEP）分析确定了在刺激后 160-190ms 发生的一个特定时期内，潜在源的配置发生变化。源分析进一步表明，在高 VSWM 背景下，颞叶和额叶资源的参与增加，同时出现枕顶叶的下调。总的来说，这些数据表明，支持工作记忆的认知控制机制可能选择性地增强与独立目标相关的并发视觉处理。更广泛地说，我们的发现与理论模型一致，该模型暗示额叶区域参与协调和优化多个目标的记忆和感知资源。
