Reliability Analysis Of Effective Connectivity For Resting State FMRI

The human brain is a highly complex physiological neural network system,which is divided into 50 cortical regions with different functions.The brain function area through brain functional network realizes individual cognition,attention,memory,movement,thinking,language,emotion and other cognitive behaviors.The study of brain function network can explore the mechanism of brain function.fMRI has noninvasive,repeatable characteristics,high temporal and spatial resolution.It is widely applied to brain functional network.Resting state fMRI is close to the real brain physiological state,without complicated experimental design and task requirements,and has easy operation,good repeatability,stable and reliable information.It has obvious advantages to investigate multiple model data especially brain disease model,and is gradually applied to the brain functional network.Effective connectivity can be applied to fMRI to analysis brain functional network,exploring the mechanism of cerebral nervous system response and understanding the principle of information processing and information transmission of human brain function.It have a good development to explore the mechanism of brain cognitive function and the pathogenesis of brain functional diseases.Based on the resting state fMRI and focusing on the effective connectivity method to investigate deeply the reliability of effective connectivity for resting state fMRI.Granger Causality Analysis(GCA)and Dynamic Causal Modeling(DCM)of effective connectivity methods can be applied to the study of the analysis of brain functional network for resting state fMRI.But their reliability to effective connectivity analysis has still been a unsure problem.Multivariate GCA can simultaneously analyze the causal relationship between multiple nodes of brain functional network.Spectral dynamic causal model(spDCM)found in frequency domain explores the dynamic causal relationship of nodes in the brain functional network.The present study focuses on the two effective connectivity methods and first study their reliability of effective connectivity analysis of resting fMRI.In this paper,the regions of interest for multivariate GCA and spDCM analysis are extracted with sphere model,and anatomical structural template model that is firstly applied to spDCM.Multivariate GCA and spDCM based the regions analyze resting state fMRI.The present results show that for the effective connectivity network of resting state fMRI to multivariate GCA and spDCM analysis there is a certain reliability and consistency,and that the connectivity strength between the structural template model and the sphere model is different,but that the causal relationship between nodes is consistent.spDCM is more sensitive to analyze the low frequency fMRI signal,and realistic to describe the activity of the brain functional network than the multivariate GCA,but which can detect accurately.the existing effective connectivity.There have been no standard constraints on the scanning length of the resting fMRI imaging.Various resting state fMRI signal time series lengths occurred in the study of brain functional networks,and few studies focused on the scanning length parameters of the effective connectivity for resting state fMRI.The present paper study the relationship between the scanning length and the reliability of multivariate GCA and spDCM by simulating experiments to simulate resting state fMRI data.The present results show that multivariate GCA is suitable for the shorter scanning length range of resting state fMRI,and spDCM for longer periods of resting state fMRI.This paper focusing on the depressive disorder disease model investigate the effect of the scanning length to effective connectivity for the real resting state fMRI.The results demonstrated that the scanning length affected the effective connectivity network for multivariate GCA and spDCM for resting state fMRI analysis.Different scanning length corresponded to different effective connectivity network.The effective scanning length range for the effective connectivity method can obtain a more reliable and accurate results,and the effective connectivity method for the appropriate scanning length can also get a more admirable results.