Abstract：
It is important to explore causal relationships in functional magnetic resonance imaging study. However, the traditional effective connectivity analysis method is easy to produce false causality, and the detection accuracy needs to be improved. In this paper, we introduce a novel functional magnetic resonance imaging effective connectivity method based on the asymmetry detection of transfer entropy, which quantifies the disparity in predictive information between forward and backward time, subsequently normalizing this disparity to establish a more precise criterion for detecting causal relationships while concurrently reducing computational complexity. Then, we evaluate the effectiveness of this method on the simulated data with different level of nonlinearity, and the results demonstrated that the proposed method outperforms others methods on the detection of both linear and nonlinear causal relationships, including Granger Causality, Partial Granger Causality, Kernel Granger Causality, Copula Granger Causality, and traditional transfer entropy. Furthermore, we applied it to study the effective connectivity of brain functional activities in seafarers. The results showed that there are significantly different causal relationships between different brain regions in seafarers compared with non-seafarers, such as Temporal lobe related to sound and auditory information processing, Hippocampus related to spatial navigation, Precuneus related to emotion processing as well as Supp_Motor_Area associated with motor control and coordination, which reflects the occupational specificity of brain function of seafarers.
摘要：
在功能磁共振成像研究中探索因果关系很重要。然而,传统的有效连通性分析方法容易产生错误的因果关系,检测精度有待提高。在本文中,提出了一种新的基于传输熵非对称性检测的功能磁共振成像有效连通性方法,量化了前向和后向时间之间预测信息的差异，随后对这种差异进行归一化，以建立更精确的标准来检测因果关系，同时降低计算复杂度。然后，我们对具有不同非线性水平的模拟数据评估了该方法的有效性，结果表明，该方法在检测线性和非线性因果关系方面优于其他方法，包括格兰杰因果关系,部分格兰杰因果关系,内核格兰杰因果关系，CopulaGranger因果关系,和传统的传递熵。此外，我们将其应用于研究海员大脑功能活动的有效连接。结果表明,与非海员相比,海员不同大脑区域之间存在显著不同的因果关系,例如与声音和听觉信息处理有关的颞叶，海马与空间导航有关，与情绪处理有关的Precuneus以及与运动控制和协调有关的Suppp_Motor_Area，这反映了海员脑功能的职业特异性。
