Researches On Attention Network In ADHD Patients In FMRI

Attention-deficit/hyperactivity disorder(ADHD) is characterized by impaired attention, disorganization, and hyperactivity-impulsivity. Neuroimaging studies have demonstrated dysfunction of attention networks in ADHD. The altered causal relationship between the dorsal and ventral attention networks(DAN & VAN) may underlie the attention dysfunction of ADHD, however, having got little attention. In the current study, Granger Causality analysis method was used to explore the relaitonship between DAN and VAN and to reveal the physiology mechanism. The main contents are:1: Amplitude of Low Frequency Fluctuation(ALFF) method was used to explore the brain activity of the ADHD patients in four bands. We found abnormal ALFF in Middle Frontal Gyrus, Sensorimotor Cotex, Medial Frontal Gyrus and precuneus.2: Voxel-wise Granger Causality Strength(GCS) was adopted to analyze the causal relationship between DAN and VAN in twenty-nine children with ADHD-combined subtype and thirty-three typically developing children(TD) using resting-state neuroimaging data. Compared to TD, children with ADHD had increased GCS in bilateral frontal eye fields(FEF) and right ventral frontal cortex(VFC). Then, The out-degree network analysis further revealed the informaition transfer between the DAN and VAN. In this study, abnormal information flow from the FEF to VFC, from FEF to temporo-parietal junction(TPJ), and from VFC to FEF were detected.3: The increased information flow among FEF, VFC, and TPJ was replicated by the reproducibility analysis using a dataset from ADHD-200 online. These results highlight the hub roles of the FEF, VFC, and TPJ in linking the DAN and VAN from the perspective of information transfer, and indicate that the abnormal attention control system and interplay between DAN and VAN may result in the pathophysiology of inattention and hyperactivity in ADHD.