Cognitive Neuroscience Lab, Department of Psychology and Health Studies, University of Saskatchewan, 9 Campus Dr., Saskatoon, SK, S7N 5A5, Canada.
Brain Struct Funct. 2023 Mar;228(2):651-662. doi: 10.1007/s00429-023-02613-2. Epub 2023 Feb 1.
The relationship between structural and functional connectivity in the human brain is a core question in network neuroscience, and a topic of paramount importance to our ability to meaningfully describe and predict functional outcomes. Graph theory has been used to produce measures based on the structural connectivity network that are related to functional connectivity. These measures are commonly based on either the shortest path routing model or the diffusion model, which carry distinct assumptions about how information is transferred through the network. Unlike shortest path routing, which assumes the most efficient path is always known, the diffusion model makes no such assumption, and lets information diffuse in parallel based on the number of connections to other regions. Past research has also developed hybrid measures that use concepts from both models, which have better predicted functional connectivity from structural connectivity than the shortest path length alone. We examined the extent to which each of these models can account for the structure-function relationship of interest using graph theory measures that are exclusively based on each model. This analysis was performed on multiple parcellations of the Human Connectome Project using multiple approaches, which all converged on the same finding. We found that the diffusion model accounts for much more variance in functional connectivity than the shortest path routing model, suggesting that the diffusion model is better suited to describing the structure-function relationship in the human brain at the macroscale.
人类大脑结构连接和功能连接之间的关系是网络神经科学的核心问题，也是我们能够有意义地描述和预测功能结果的重要主题。图论已被用于基于结构连接网络生成与功能连接相关的度量，这些度量通常基于最短路径路由模型或扩散模型，这两种模型对信息如何通过网络传输有不同的假设。与最短路径路由不同，最短路径路由假设总是知道最有效的路径，而扩散模型则没有这样的假设，而是根据与其他区域的连接数量让信息并行扩散。过去的研究还开发了混合度量，这些度量结合了两种模型的概念，它们比最短路径长度单独预测功能连接的效果更好。我们使用仅基于每个模型的图论度量来检查每个模型在多大程度上可以解释感兴趣的结构-功能关系。我们使用多种方法对人类连接组计划的多个分区进行了分析，所有方法都得出了相同的结论。我们发现，扩散模型比最短路径路由模型解释了更多的功能连接变异性，这表明扩散模型更适合描述宏观尺度上人类大脑的结构-功能关系。
