Abnormal Functional Connectivity in Cognitive Control Network, Default Mode Network, and Visual Attention Network in Internet Addiction: A Resting-State fMRI Study.

Yang Wang,Lingrui Zhang,Hui Li,Dezhong Yao,Zhiliang Li,Yu Dai,Bo Sun,Cheng Luo,Xin Li,Yun Qin,Chenchen Zhang,Tianmin Zhu,Chao Wen

doi:10.3389/fneur.2019.01006

Abstract

Internet addiction (IA) has become a global mental and social problem, which may lead to a series of psychiatric symptoms including uncontrolled use of internet, and lack of concentration. However, the exact pathophysiology of IA remains unclear. Most of functional connectivity studies were based on pre-selected regions of interest (ROI), which could not provide a comprehensive picture of the communication abnormalities in IA, and might lead to limited or bias observations. Using local functional connectivity density (lFCD), this study aimed to explore the whole-brain abnormalities of functional connectivity in IA. We evaluated the whole-brain lFCD resulting from resting-state fMRI data in 28 IA individuals and 30 demographically matched healthy control subjects (HCs). The correlations between clinical characteristics and aberrant lFCD were also assessed. Compared with HCs, subjects with IA exhibited heightened lFCD values in the right dorsolateral prefrontal cortex (DLPFC), left parahippocampal gyrus (PHG), and cerebellum, and the bilateral middle cingulate cortex (MCC) and superior temporal pole (STP), as well as decreased lFCD values in the right inferior parietal lobe (IPL), and bilateral calcarine and lingual gyrus. Voxel-based correlation analysis revealed the significant correlations between the Young's Internet Addiction Test (IAT) score and altered lFCD values in the left PHG and bilateral STP. These findings revealed the hyper-connectivity in cognitive control network and default mode network as well as the hypo-connectivity in visual attention network, verifying the common mechanism in IA and substance addiction, and the underlying association between IA, and attention deficit/hyperactivity disorder in terms of neurobiology.

Highlights

Internet addiction (IA), as a behavioral addiction, was conceptualized as the poorly controlled use of internet with impairment of interpersonal relationships, and psychological and social functioning [1]
Higher local functional connectivity density (lFCD) values (P < 0.01, with the cluster-level corrected) were observed in brain regions belonging to the DMN, including the left parahippocampal gyrus (PHG), and bilateral superior temporal pole (STP)
We further evaluated the influence of framewise displacement (FD), which might partially index physiological noise [30, 31]

Summary

Introduction

Internet addiction (IA), as a behavioral addiction, was conceptualized as the poorly controlled use of internet with impairment of interpersonal relationships, and psychological and social functioning [1]. With the popularity of the internet and the improvement of information technology in the last 2 decades, IA has become a serious public health problem due to its high prevalence around the world [2, 3]. The potential risk of IA has attracted growing concerns from worldwide researchers, and mounting studies, and papers have been published. Besides uncontrolled use of internet, multiple comorbid psychiatric symptoms of IA have been revealed by clinical studies, including anxiety, depression, and lack of concentration [5, 6]. Epidemiological research further demonstrated that attention deficit/hyperactivity disorder (ADHD), unsociable personality, and bad relationship with parents were high risk factors of IA [6,7,8]. The exact pathophysiology of IA has not been fully understood yet, and the underlying mechanism of the coexistence of IA, and comorbid symptoms remains unclear

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