**2. Analysis and understanding the complex brain network**

The human brain consists of a complete and comprehensive network map of neuronal connections called human connectome. The normal maturation of these interconnected neurons associated with normal development of high cortical functions and motor skill consolidation. The failure of this network maturation can lead to some serious neurodevelopmental disabilities [12].

The connectivity of this complex brain network can be classified into three types: structural connectivity, functional connectivity and effective connectivity [13]. Structural connectivity can be further subdivided into two types. First the anatomical connections that links a bundle of neural elements and second is the interregional fibers linking cortical to subcortical gray matter areas [13].

Functional connectivity is obtained from time series analysis and reflects the statistical dependence within neural units. This time sense date can be defined by different methods which include EEG, Functional magnetic resonance imaging (fMRI) and magnetoencephalography (MEG) [13].

Effective connectivity (EC) defines the casual effects that one neural system exerts over another. EC cannot be assessed directly so several techniques have been used to study the EC. The Dynamic Casual Modeling (DCM) is the main method for evaluating EC by analyzing data from neuroimaging studies such as Functional Magnetic Resonance Imaging (fMRI) [14].
