Application of graph theory to both resting-state and task-based fMRI data to uncover brain-behavior relationships related to therapy outcomes in aphasia

项目摘要 虽然有许多治疗模式存在失语症康复与行为上的成功 然而，关于恢复过程中神经重组的“最佳”模式仍然存在很大争议。这 缺乏共识可能部分是由于对神经重组和神经元再生之间的联系的不完全探索。 行为本计画将应用图论的方法于任务型与休息型两种状态 fMRI（rs-fMRI）数据，以检查与治疗结果相关的功能连接变化 失语症目前，图论和rs-fMRI在临床失语症研究中的应用不足。图论是 作为一种有意义的技术，在认知科学的其他领域越来越受欢迎， 脑网络动力学静息状态功能磁共振成像在临床研究的其他领域越来越受欢迎， 这是一种容易获得的、信息量很大的一般认知功能测量方法。 20名失语症（PWA）受试者将在四个时间点使用fMRI进行扫描。扫描1之间 和扫描2，将不提供治疗，为每个PWA建立基线对照。在扫描2和 扫描3，将提供十周的单词发现治疗。在扫描3和扫描4之间，将不进行治疗。 提供，允许测量维护效果。所使用的处理是抽象词检索 训练之所以选择这种治疗方法，是因为它不仅能成功地改善抽象 词检索，而且还改进了未训练的相关具体词的检索（即，一般化） （Kiran，Sandberg，& Abbott，2009; Sandberg & Kiran，2014）。这使得治疗更有效， 促进积极神经变化的好候选人。此外，抽象和具体的词已经被 显示出不同的神经激活模式这就可以对直接培训进行系统的审查 以及治疗对大脑重组的泛化效应。对于图论分析， 将使用由Hillary博士开发的数据驱动的空间约束方法定义感兴趣区域（ROI）， 莫莱纳一旦为每个时间点定义了相关性矩阵，将使用图论测量方法。 在每个时间点进行计算和比较，以系统地检查功能连接的变化 与治疗结果有关。 本提案中的方法学方法是创新的，在使用两次基线扫描之前， 治疗和治疗后的两次维持扫描以及图论和rs-fMRI在 检查失语症患者治疗相关的脑重组。该项目的顺利完成是 预计将有助于为中风后最佳重组模式的现有理论提供信息， 建立信息和适当的方法来测量失语症的大脑重组。

Project Summary Although many treatment paradigms exist for aphasia rehabilitation with behaviorally successful outcomes, there is still much debate regarding the “best” pattern of neural reorganization during recovery. This lack of consensus may be due, in part, to incomplete exploration of the link between neural reorganization and behavior. The proposed project will apply graph theoretical measures to both task-based and resting-state fMRI (rs-fMRI) data to examine changes in functional connectivity related to treatment outcomes in persons with aphasia. Graph theory and rs-fMRI are currently underutilized in clinical aphasiology. Graph theory is gaining popularity in other areas of cognitive science as a meaningful technique for the characterization of brain network dynamics. Resting-state fMRI has been gaining popularity in other areas of clinical research as an easily acquired and informative measure of general cognitive functioning. Twenty participants with aphasia (PWA) will be scanned using fMRI at four time points. Between scan 1 and scan 2, no therapy will be provided, establishing a baseline control for each PWA. Between scan 2 and scan 3, ten weeks of word finding therapy will be provided. Between scan 3 and scan 4, no therapy will be provided, allowing for measurement of maintenance effects. The treatment used is abstract word retrieval training. This treatment was chosen because it has been shown to be not only successful at improving abstract word retrieval, but also improving retrieval of related concrete words that are not trained (i.e., generalization) (Kiran, Sandberg, & Abbott, 2009; Sandberg & Kiran, 2014). This makes the treatment more effective and a good candidate for promoting positive neural changes. Furthermore, abstract and concrete words have been shown to have differing neural activation patterns. This allows for the systematic examination of direct training and generalization effects of treatment on brain reorganization. For the graph theory analysis, regions of interest (ROIs) will be defined using a data-driven spatially-constrained approach developed by Drs. Hillary and Molenaar. Once correlations matrices are defined for each time point, graph theoretical measures will be calculated and compared at each time point to systematically examine changes in functional connectivity related to therapy outcomes. The methodological approach in this proposal is innovative in the use of two baseline scans before treatment and two maintenance scans after treatment and the application of graph theory and rs-fMRI to examine treatment-related brain reorganization in aphasia. The successful completion of this project is expected to help inform current theories of optimal reorganization patterns after stroke and provide groundwork for establishing informative and appropriate methods for measuring brain reorganization in aphasia.