基于多模态MRI技术研究网络成瘾冲动控制行为的神经网络机制

Internet addiction (IA) is currently becoming a serious mental health issue around the world because of the overuse internet. Therefore, it is of importance to address the neural mechanism underlying IA. With our previous findings，we hypothesized that IA was mainly resulted from the neural dysregulation of impulse-control network at the system level. In the current study, we recruited students with IA and well-matched cognitive normal (CN) from university and high middle school in Beijing. Using the multimodality magnetic resonance image and several analyzed approaches, the structural and functional network architectures were investigated to address the underlying mechanism of dysfunctional impulse-control in subjects with IA. For all subjects, neuropsychological battery was first used to assess the cognitive function; Brain density and volumes of gray matter and white matter, diffusion tensor image (DTI) tracing white matter integrity were quantitatively used to analyze the structural network alteration in IA under rest; Second, two tasks (Cognitive control task and craving induced by game videos) were used to investigate the changes of structural and functional network patterns and information integration capacity in IA subjects compared to CN subjects; Finally, combining with neuropsychological examination and structural and functional network patterns, multiple linear regression analysis was used to assess the neural basis of impulse-control network underlying IA. Our studies will make sure to establish the neural model of cognitive-control behavior in IA and provide new insight for strategy of therapy and intervention of IA.

随着互联网的普及，网络成瘾（Internet Addiction，）已经成为严重的公共健康问题，阐明IA的神经机制具有重要意义。本项目在前期研究的基础上，提出"网络成瘾系大脑冲动控制神经网络功能调控障碍"的科学假设，拟选择单纯网络游戏成瘾的大、中学生，评估其神经认知功能状态；采用多模态磁共振成像技术及多种分析手段，研究IA者大脑结构和功能神经网络特征，对灰/白质密度、体积，白质纤维束精确定位和定量分析；结合任务刺激模式（认知控制任务和渴求任务）分析不同状态下的功能神经网络模式特征及其信息整合态，利用多变量回归分析逐层深入研究网络成瘾者冲动控制障碍的神经网络基础，初步建立认知调控与非物质成瘾行为交互作用的理论模型，为网络成瘾的性质认定以及防治策略提供科学依据。

网络成瘾表现为对互联网使用的冲动性失控而导致个体显著的社会和心理损害。本课题利用多模态 MRI 技术研究了网络成瘾冲动控制行为的神经网络机制。主要取得如下进展：(1) 利用基于结构MRI的VBM分析方法和基于弥散张量成像的TBSS分析方法分析了网络成瘾者脑结构网络变化特征，发现海马、运动区和额下回灰质体积的变化和胼胝体各向异性的增高，这可能是网络成瘾者冲动控制缺陷的脑结构基础；(2) 采用种子点相关性分析和独立成分分析方法考察了网络成瘾者在静息状态下和线索诱发状态下的功能网络变化特征，发现静息状态下默认网络和控制网络内部功能连接的下降和奖赏网络内部功能连接的增强，以及默认网络和突显网络之间的功能连接下降，而在线索诱发状态下脑岛和内侧前额叶皮层的功能连接强度与个体的渴求程度之间具有正相关关系；(3) 采用相同的方法研究了物质成瘾者脑结构和功能的异常，结果显示网络成瘾与其它成瘾性疾病具有某些类似的神经网络异常，进一步说明脑功能网络之间的失衡可能是不同类型成瘾者共同的神经基础；(4) 结合脑网络和神经经济学方法研究了成瘾人群价值决策网络的失衡与冲动性的神经关联模式，证实大脑奖赏系统和控制系统是评价系统的两个方面，按照两个系统的区域进行量化得到个体的执行控制指数和动机驱动指数，则可以清晰看到成瘾者中价值决策网络之间的失衡与BIS冲动得分具有显著相关性。研究为深入理解成瘾的神经生物学机制，制定网络成瘾的防治策略提供科学依据。