Interhemispheric Connectivity Supports Load-Dependent Working Memory Maintenance for Complex Visual Stimuli.
Interhemispheric Connectivity Supports Load-Dependent Working Memory Maintenance for Complex Visual Stimuli.
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DOI：
10.1089/brain.2021.0171
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发表时间：
2022-12
影响因子：
3.4
通讯作者：
中科院分区：
文献类型：
--
作者：
研究工作记忆的神经基础的一种方法是改变编码时的信息量，然后测量延迟期维持过程中的活动和连接。一个标志性的发现是，随着负荷的增加，额顶叶脑区之间的延迟活动和连通性增加。然而，大多数工作记忆研究在编码过程中使用简单的刺激，在延迟过程中使用未填充的间隔。在这项研究中，我们问延迟期活动和连接性的变化，在低负荷和高负荷维持复杂的刺激。22名受试者在头皮脑电图（EEG）过程中完成了一个修改后的斯滕贝格WM任务，其中有两个或五个自然场景作为刺激。在每一次试验中，延迟被填充相位加扰的场景，以提供具有与编码期间呈现的相似颜色和空间频率的视觉感知控制。延迟期间的功能连接通过锁相值（PLV）进行评估。结果表明，降低θ/α延迟活动幅度在高与低WM负荷在额叶，中央和顶叶的来源。在低负荷期间具有更高连通性的网络包括（1）θ/α频带中的左额和右后颞源之间的PLV增加，（2）α和下β频带中的右前颞源和左中央源，以及（3）θ、α和下β频带中的左前颞源和后颞源。研究结果表明，当有限的注意力资源是必不可少的过滤时，大脑半球间的连接在WM维护复杂的刺激与负载调制的作用。到目前为止，已经在很大程度上使用简单的刺激，包括字母，数字和形状，并在未填充的WM延迟间隔期间，研究了大脑连接的模式。较少的研究描述的功能连接的变化，在维护更自然的刺激存在干扰。在本研究中，我们采用了基于场景的WM任务在健康人的脑电图，并发现，在低负荷WM维护与分心增加额颞叶网络的半球间连接。这些研究结果表明，在维护复杂的刺激时，注意力资源是必不可少的过滤，增加大脑半球间的连接的作用。
One manipulation used to study the neural basis of working memory (WM) is to vary the information load at encoding, then measure activity and connectivity during maintenance in the delay period. A hallmark finding is increased delay activity and connectivity between frontoparietal brain regions with increased load. Most WM studies, however, employ simple stimuli during encoding and unfilled intervals during the delay. In this study, we asked how delay period activity and connectivity change during low and high load maintenance of complex stimuli. Twenty-two participants completed a modified Sternberg WM task with two or five naturalistic scenes as stimuli during scalp electroencephalography (EEG). On each trial, the delay was filled with phase-scrambled scenes to provide a visual perceptual control with similar color and spatial frequency as presented during encoding. Functional connectivity during the delay was assessed by the phase-locking value (PLV). Results showed reduced theta/alpha delay activity amplitude during high compared with low WM load across frontal, central, and parietal sources. A network with higher connectivity during low load consisted of increased PLV between (1) left frontal and right posterior temporal sources in the theta/alpha bands, (2) right anterior temporal and left central sources in the alpha and lower beta bands, and (3) left anterior temporal and posterior temporal sources in the theta, alpha, and lower beta bands. The findings suggest a role for interhemispheric connectivity during WM maintenance of complex stimuli with load modulation when limited attentional resources are essential for filtering. The patterns of brain connectivity subserving working memory (WM) have largely been investigated to date using simple stimuli, including letters, digits, and shapes and during unfilled WM delay intervals. Fewer studies describe functional connectivity changes during the maintenance of more naturalistic stimuli in the presence of distractors. In the present study, we employed a scene-based WM task during electroencephalography in healthy humans and found that during low-load WM maintenance with distractors increased interhemispheric connectivity in frontotemporal networks. These findings suggest a role for increased interhemispheric connectivity during maintenance of complex stimuli when attentional resources are essential for filtering.
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影响因子：
2.6
作者：
Boucher, Olivier;Dagenais, Emmanuelle;Rouleau, Isabelle
通讯作者：
Rouleau, Isabelle
影响因子：
3.7
作者：
Ellmore, Timothy M.;Ng, Kenneth;Reichert, Chelsea P.
通讯作者：
Reichert, Chelsea P.
DOI：
10.1073/pnas.1106439108
发表时间：
2011-10-18
影响因子：
11.1
作者：
Feredoes, Eva;Heinen, Klaartje;Driver, Jon
通讯作者：
Driver, Jon
影响因子：
2.4
作者：
Ille, N;Berg, P;Scherg, M
通讯作者：
Scherg, M
影响因子：
1.7
作者：
Brown, Louise A.;Forbes, Douglas;McConnell, Jean
通讯作者：
McConnell, Jean