随着网络技术在世界范围内的高速发展，网络游戏成瘾已经成为全球性的精神疾病问题；东亚地区包括中国在内一直是网络游戏成瘾的重灾区。精神疾病领域对网络游戏成瘾十分重视; 美国出版的《精神疾病诊断与统计手册》第5版和《国际疾病分类系统》第11版相继将网络游戏成瘾纳入亟待研究和解决的问题。因此，对网络游戏成瘾的研究具有重要的实践和理论意义。

成瘾的情感联结偏向，即相比长期成瘾行为引发的消极后果和体验, 成瘾者倾向于自动化地将成瘾相关线索与成瘾行为带来的即时性积极奖赏体验联结在一起；表现为在使用启动任务或内隐联想任务测量成瘾的情感联结偏向时，成瘾者对成瘾线索与积极情绪词配对的反应时快于成瘾线索与消极情绪词的配对反应。物质成瘾和赌博成瘾的研究发现对成瘾线索的积极情感联结偏向是成瘾行为形成、维持和复发的重要内隐动因。以往研究发现网络游戏成瘾在核心症状、成因、影响因素和干预等各方面与物质成瘾具有相似的特点及认知神经机制。因此考察网络游戏成瘾的情感联结偏向及其干预矫正对于深化对网络游戏成瘾的理解和促进网络游戏成瘾的干预实践具有重要价值。围绕网络游戏成瘾的情感联结偏向，本论文分以下三个部分展开：（1）网络游戏成瘾者的情感联结偏向的特点及其神经机制；（2）情感联结偏向矫正训练对网络游戏成瘾的干预效果；（3）情感联结偏向矫正训练干预网络游戏成瘾的起效机制。具体研究内容如下：

研究一是横断比较研究；使用启动任务、改编版的线索诱发任务结合磁共振技术，对44名网络游戏成瘾者和38名游戏玩家进行考察，探索网络游戏成瘾者是否对网络游戏线索存在积极情感联结偏向及情感联结偏向的神经机制。研究二是随机对照的干预研究；针对网络游戏成瘾者对网络游戏线索的积极情感联结偏向开展矫正训练。90名网络游戏成瘾者被随机分配到干预组或对照组。干预组的训练包含连续6天的认知任务。该训练旨在让被试将网络游戏与消极情绪建立联结。具体而言，在训练任务中网络游戏图片始终与消极情绪词对一起呈现，健康娱乐活动图片始终与积极情绪词对一起呈现；每个词对中有一个固定的词与高概率获得奖赏相关；被试通过按键选择词语让自己获得尽可能多的奖赏，在无意识之中习得新的情感联结。对照组中，所有词都是中性词，其他设置均与干预组相同。训练任务前、后和训练任务后8周内干预组和对照组的被试接受包括网络游戏相关的情感联结偏向、强迫性思维和行为、周游戏时间、成瘾程度等一系列指标的问卷和行为测试，用于考察干预的行为效果。研究三以研究二为基础，考察干预的起效机制。研究二中干预组和对照组的被试在训练任务前、后还在磁共振扫描仪中完成了改编版的线索诱发任务，用于考察情感联结偏向矫正训练的神经机制。研究三还利用干预组前测的行为和脑数据结合机器学习算法考察了预测干预效果的指标。主要的研究结果如下：

（1）相比游戏玩家，网络游戏成瘾者对网络游戏图片的积极情感联结偏向更大，自动化加工网络游戏图片时背侧纹状体激活更强，对网络游戏图片抑制性加工时前扣带回激活不足。网络游戏成瘾的积极情感联结偏向与背侧纹状体的激活程度正相关。

（2）情感联结偏向矫正干预显著削弱了网络游戏成瘾的积极情感联结偏向、网络游戏相关的强迫性思维和行为、周网络游戏时间和网络游戏成瘾程度；干预效应在训练后8周时仍然存在。

（3）情感联结偏向矫正干预削弱了对网络游戏图片抑制性加工时背侧纹状体的激活，削弱了对网络游戏图片进行自动化加工时背侧纹状体与眶额皮层的功能联结，增强了对网络游戏图片进行抑制性加工时背侧纹状体与腹侧前额皮层的功能联结。干预诱发的背侧纹状体的神经活动降低量，背侧纹状体与腹侧前额皮层的功能联结的增强量，均与积极情感联结偏向的削弱量正相关；干预诱发的背侧纹状体与眶额皮层的功能联结的降低量与网络游戏相关的强迫性的削弱量正相关。干预诱发的网络游戏相关的强迫性的降低量中介了背侧纹状体与眶额皮层的削弱量对网络游戏成瘾程度削弱量的正相关。

（4）干预前测时网络游戏成瘾者对健康娱乐活动图片进行控制性加工的实验条件下，背侧纹状体与其他脑区的功能连接能显著预测干预带来的网络游戏相关的强迫性的削弱程度，背侧纹状体与额区脑区的功能连接在预测中贡献值最突出。

研究结论：网络游戏成瘾者存在积极情感联结偏向，该偏向与网络游戏线索诱发的背侧纹状体的神经活动相关。情感联结偏向矫正训练能有效削弱网络游戏成瘾的积极情感联结偏向并缓解网络游戏成瘾相关的核心症状。干预效应背后的主要神经机制是重塑背侧纹状体-额区通路的神经活动。对健康奖赏替代物能良好进行增强奖赏体验的控制性加工的网络游戏成瘾者可能更多从情感联结偏向矫正训练中获益。

本文的核心创新点：（1）采用严谨的随机分组和双盲的干预设计，首次在网络游戏成瘾者中验证了情感联结偏向矫正训练的干预效果。对于缓解网络游戏成瘾问题和推动公众健康具有重要意义。（2）本文不仅考察了矫正训练的干预效果，还包含对情感联结偏向矫正训练起效机制的探索，这对推动个性化的网络游戏成瘾矫正方案和提高干预效率具有重要意义。（3）异常-干预和干预效果-干预起效机制的研究框架有助于同时从横断比较和干预操纵的角度加深对网络游戏成瘾的认知神经机制的理解，为未来对网络游戏成瘾更科学、严谨的诊断提供依据。

With the rapid development of internet use worldwide, internet gaming disorder (IGD) has been a global concern. It’s particularly severe in eastern Asia areas including China. Included in DSM-5 and ICD-11, IGD is regarded as an issue warrant urgent research.

 Addiction-related emotional association bias (EAB) refers to that individuals with addictions automatically associate addiction-cue with immediate、rewarding/positive emotions of addictive behaviors rather long term negative outcomes and emotions. Research in substance addiction and gambling disorder suggest that positive EAB towards addiction-cue is an important implicit driving force of addiction formation, maintenance, and relapse. Previous research in IGD show that IGD may share similar core symptoms, causes, affecting factors and interventions with substance addiction. Therefore, examination of EAB in IGD and development of corresponding intervention will be of great value to facilitating understandings towards IGD and treatment efforts in IGD. Focused on EAB in IGD, the current thesis included three parts: (1) The features and neural mechanisms of EAB in IGD; (2) The intervention effects of EAB modification (EABM) training; (3) The neural mechanisms of intervention effects. Below are the details.

Study 1 was a cross-sectional research. Using the priming task and revised cue-reactivity task combined with fMRI technique, this study examined features and neural mechanisms of EAB in IGD among 44 individuals with IGD and 38 individuals with gamers. Study 2 was a randomized control intervention, which targeted the feature of EAB in IGD demonstrated in Study 1. Ninety individuals with IGD were randomly assigned to the an EABM or sham training. The EABM intervention involved six consecutive days of exposure to negative emotional terms linked to gaming stimuli and positive terms linked to non-gaming healthy-alternative stimuli. The sham training involved similar stimuli linked to neutral words. Participants received several behavioral assessments including gaming-related EAB, compulsive thoughts and behaviors, weekly gaming time, severity of internet gaming pre-training、post-training and during a 8-week follow up. Study 3 was based on Study 2 and examined neural mechanisms of intervention effects. Participants in Study 2 also underwent event-related fMRI while performing a revised cue-reactivity task pre-training and post-training. Neural changes in neural responses elicited by the task post-training (vs. pre-training) were used to examine neural mechanisms of intervention effects. We also used neural responses elicited by the task pre-training to examine features that might predict intervention effects using a machine learning method. Below are main results.

(1) Compared with gamers, individuals with IGD revealed larger gaming-related positive EAB, accompanied with increased activation in dorsal striatum (DS) during automation processing of gaming-cue and decreased activation in anterior cingulate cortex (ACC) during controlled processing of gaming-cue. Gaming-related positive EAB was positively associated with DS activation.

(2) The EABM (vs. sham) decreased gaming-related positve EAB, compulsive thoughts and behaviors, severity of IGD post-training (vs. Pre-training）. Some intervention effects lasted within 8 weeks post-training.

(3) EABM training involved decreased activation in the bilateral dorsal striatum (DS) in the revised cue-reactivity task, and altered left DS-centric functional connectivity with ventral prefrontal cortical regions, which correlated with decreases in gaming-related EABs or compulsive gaming-related thoughts and behaviors.

(4) In healthy-activity-increase condition, functional connectivities between the left DS and other brain regions pre-training significantly predicted intervention-elicited changes rates of gaming-related compulsivity in the EABM group.

All these results revealed that individuals with IGD shows gaming-related positive EAB that may be associated with neural activity of DS-frontal pathway. The EABM training may alleviate symptoms of IGD via reshaping fronto-striatal pathway.

Individuals who can well upregulate motivation/craving towards healthy-activity may benefit more from the EABM training.

The thesis is innovative in several aspects. First, using rigid randomized control design, it is the first research which demonstrates relatively robust clinical effects of EABM training in IGD. This contributes to alleviation of IGD issue and public psychiatry health. Second, this research included examinations of both intervention effects and neural mechanisms underlying intervention effects, which is of important value to development of individualized and efficient treatments in IGD.