Different Roles of Direct and Indirect Frontoparietal Pathways for Individual Working Memory Capacity
Different Roles of Direct and Indirect Frontoparietal Pathways for Individual Working Memory Capacity
复制标题
DOI：
10.1523/jneurosci.1376-14.2016
复制
发表时间：
2016-03-09
影响因子：
5.3
通讯作者：
Derrfuss, Jan
中科院分区：
文献类型：
--
作者：
Ekman, Matthias;Fiebach, Christian J.;Derrfuss, Jan
在工作记忆中暂时存储和操纵信息的能力是人类智力的标志，并且在个体之间存在很大差异，但是对工作记忆容量（WMC）中这些差异的结构性大脑相关性知之甚少。在两项独立的研究中，收集了70名和109名健康个体的弥散MRI数据和WMC评分。使用概率纤维束成像和网络分析的组合的白色物质束，我们检查是否结构脑网络的属性是预测个人WMC。这两项研究的证据表明，与低能力个体相比，高能力个体的外侧前额叶皮层和后顶叶皮层连接得更紧密。重要的是，我们的网络方法进一步能够分离与连接额叶和顶叶区域的两种不同通路相关的假定功能角色：皮质皮质通路和皮质下通路。在研究1中，参与者被要求保持和更新工作记忆项目，直接和间接通路的连接是预测WMC。与此相反，在研究2中，参与者被要求保持工作记忆项目没有更新，只有直接通路的连接是预测个人WMC。我们的研究结果表明，在连接额叶和顶叶区域的电路中，直接的额顶叶连接可能支持存储和维护，而皮层下介导的连接支持工作记忆内容的灵活更新的一个重要的分离。
The ability to temporarily store and manipulate information in working memory is a hallmark of human intelligence and differs considerably across individuals, but the structural brain correlates underlying these differences in working memory capacity (WMC) are only poorly understood. In two separate studies, diffusion MRI data and WMC scores were collected for 70 and 109 healthy individuals. Using a combination of probabilistic tractography and network analysis of the white matter tracts, we examined whether structural brain network properties were predictive of individual WMC. Converging evidence from both studies showed that lateral prefrontal cortex and posterior parietal cortex of high-capacity individuals are more densely connected compared with low-capacity individuals. Importantly, our network approach was further able to dissociate putative functional roles associated with two different pathways connecting frontal and parietal regions: a corticocortical pathway and a subcortical pathway. In Study 1, where participants were required to maintain and update working memory items, the connectivity of the direct and indirect pathway was predictive of WMC. In contrast, in Study 2, where participants were required to maintain working memory items without updating, only the connectivity of the direct pathway was predictive of individual WMC. Our results suggest an important dissociation in the circuitry connecting frontal and parietal regions, where direct frontoparietal connections might support storage and maintenance, whereas subcortically mediated connections support the flexible updating of working memory content.