Examining working memory task acquisition in a disrupted neural network
Examining working memory task acquisition in a disrupted neural network
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DOI：
10.1093/brain/awr043
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发表时间：
2011-05-01
期刊：
影响因子：
14.5
通讯作者：
Good, David C.
中科院分区：
文献类型：
--
作者：
Hillary, Frank G.;Medaglia, John D.;Good, David C.
越来越多的文献研究了患有神经系统疾病（如创伤性脑损伤）的个体在工作记忆任务中的大脑激活。这些研究为理解中度和重度创伤性脑损伤后发生的功能性脑变化奠定了基础，但对地形脑“激活”差异的关注忽略了分布式神经网络中节点通信方式的潜在改变。本研究利用最新开发的连接模型（扩展统一结构方程模型），以检查在一个完善的工作记忆任务（n-回）的个人持续中度和重度创伤性脑损伤的表现。我们的目标是使用地形激活分析中观察到的结果作为第二级有效连接建模的基础。研究结果揭示了重要的组间差异，在任务获取过程中，与控制样本显示快速内左半球连接增加和创伤性脑损伤的样本显示持续升高的内右半球连接。这些研究结果还指出，在任务执行过程中，从“早期”到“晚期”的重要成熟效应，包括右前额叶皮质参与减少，以及随着任务暴露的增加，连接性从前部到后部的转变。我们预计，这种方法的功能成像数据分析代表了一个重要的未来方向，了解神经可塑性是如何表达在大脑疾病。
There is mounting literature that examines brain activation during tasks of working memory in individuals with neurological disorders such as traumatic brain injury. These studies represent a foundation for understanding the functional brain changes that occur after moderate and severe traumatic brain injury, but the focus on topographical brain-'activation' differences ignores potential alterations in how nodes communicate within a distributed neural network. The present study makes use of the most recently developed connectivity modelling (extended-unified structural equation model) to examine performance during a well-established working-memory task (the n-back) in individuals sustaining moderate and severe traumatic brain injury. The goal is to use the findings observed in topographical activation analysis as the basis for second-level effective connectivity modelling. Findings reveal important between-group differences in within-hemisphere connectivity during task acquisition, with the control sample demonstrating rapid within-left hemisphere connectivity increases and the traumatic brain injury sample demonstrating consistently elevated within-right hemisphere connectivity. These findings also point to important maturational effects from 'early' to 'late' during task performance, including diminished right prefrontal cortex involvement and an anterior to posterior shift in connectivity with increased task exposure. We anticipate that this approach to functional imaging data analysis represents an important future direction for understanding how neural plasticity is expressed in brain disorders.