The Mind Research Network Albuquerque, NM, USA.
Front Syst Neurosci. 2011 Feb 8;5:7. doi: 10.3389/fnsys.2011.00007. eCollection 2011.
The functional architecture of the human brain has been extensively described in terms of complex networks characterized by efficient small-world features. Recent functional magnetic resonance imaging (fMRI) studies have found altered small-world topological properties of brain functional networks in patients with schizophrenia (SZ) during the resting state. However, little is known about the small-world properties of brain networks in the context of a task. In this study, we investigated the topological properties of human brain functional networks derived from fMRI during an auditory oddball (AOD) task. Data were obtained from 20 healthy controls and 20 SZ; A left and a right task-related network which consisted of the top activated voxels in temporal lobe of each hemisphere were analyzed separately. All voxels were detected by group independent component analysis. Connectivity of the left and right task-related networks were estimated by partial correlation analysis and thresholded to construct a set of undirected graphs. The small-worldness values were decreased in both hemispheres in SZ. In addition, SZ showed longer shortest path length and lower global efficiency only in the left task-related networks. These results suggested small-world attributes are altered during the AOD task-related networks in SZ which provided further evidences for brain dysfunction of connectivity in SZ.
人类大脑的功能结构已被广泛描述为具有有效小世界特征的复杂网络。最近的功能磁共振成像（fMRI）研究发现，精神分裂症（SZ）患者在静息状态下大脑功能网络的小世界拓扑性质发生了改变。然而，关于任务背景下大脑网络的小世界性质知之甚少。在这项研究中，我们研究了听觉Oddball（AOD）任务期间 fMRI 得出的人脑功能网络的拓扑性质。数据来自 20 名健康对照者和 20 名 SZ 患者；分别分析了由每个半球颞叶中顶部激活体素组成的左、右任务相关网络。所有体素均通过组独立成分分析检测。通过偏相关分析估计左、右任务相关网络的连通性，并对其进行阈值处理以构建一组无向图。SZ 患者的两个半球的小世界值均降低。此外，SZ 患者仅在左任务相关网络中表现出较短的最短路径长度和较低的全局效率。这些结果表明，在 SZ 的 AOD 任务相关网络中，小世界属性发生了改变，为 SZ 中的连通性脑功能障碍提供了进一步的证据。
