Altered Resting-State Functional Connectivity in Internet Addicts

The purpose of this study was to examine functional disconnectivity in Internet addicts using resting-state functional Magnetic Resonance Imaging (rs fMRI). Internet addicts and demographically similar non-addicts were scanned using rs fMRI. For the connectivity analysis, Regions Of Interests (ROIs) were defined based on previous studies of addictions. The functional connectivity assessment for each subject was obtained by correlating time-series across the ROIs, resulting in 8x8 matrix for each subject. Within-group functional connectivity patterns were observed by entering the z maps of the ROIs of each subject into second-level one sample t test. Two sample t test was also performed to examine differences between two groups. A significant increase was observed in positive functional connectivity between the Orbito Frontal Cortex (OFC) and several brain regions in the nonaddicted group. However, no significant correlations in these structural connectivities were found in the Internet addiction group. The Internet addiction group presented significant negative connectivity between the OFC and insula. Our findings provide the evidence that Internet addicts have aberrant functional connectivity in the corticostriatal circuit at resting state. Particularly, we suggest that the OFC, which is associated with processing negative affect and behavioral inhibition, may play a crucial role in the pathophysiology of the Internet addiction. Keywords-Resting-state fMRI; Internet addicts; Functional connectivity; Orbitofrontal cortex