White matter tracts form the structural foundation for brain connectivity by linking discrete gray matter regions into integrated neural circuits. Neuroimaging studies have also provided in vivo evidence of atypical neural network activity, connectivity, and white matter impairments in ASD. In addition, changes in the developmental trajectory of the ASD brain appear to differ among regions, with greater abnormalities in frontal and temporal lobes than parietal and occipital lobes. Magnetic resonance imaging studies of brain anatomy in children with ASD have shown that developmental trajectory is atypical and includes early overgrowth, followed by growth retardation, and at an older age, potentially reduced brain volume. Magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI) studies have suggested that concurrent changes in gray and white matter follow distinct developmental trajectories during brain maturation. The human brain follows a precise spatiotemporal pattern of maturation that begins with phylogenetically older posterior and inferior regions and then progressively extends to more anterior and superior regions. Moreover, UF abnormities are associated with impaired socio-emotional processing and symptom severity in individuals with ASD. Therefore, it is also regarded as a link between the basic emotion processing region and the area involving higher order processing. The UF is known to be an essential connector, which bridge polar temporal regions to frontal lobe. One particularly plausible neural mechanism for the socio-affective deficits of ASD is abnormal development of the uncinate fasciculus (UF). To date, a growing number of studies have proven that there are often pronounced difficulties in regulating emotion across ASD patients. Autism spectrum disorder (ASD) is a complex neurodevelopmental condition characterized by core impairments in social interaction and social communication as well as behavioral anomalies including repetitive, restrictive, and stereotyped patterns of interests and activities (American Psychiatric Association, 2013).

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