认知与发展心理学研究室知识库

网络成瘾是指个体无法控制使用网络的强烈冲动，并最终导致其心理、社会、教育/工作等方面受损。近十几年来，网络的娱乐性和易得性使网络成瘾现象越来越严重，尤其在青少年和大学生人群中。其中，网络成瘾的子类别网游成瘾己先后被美国精神疾病诊断与统计手册第五版和国际疾病分类第十一版归为一种精神疾病。本文以青少年神经生物模型和自我调节的双系统模型为指导框架，从个体的奖赏加工与认知控制系统出发，结合问卷调查、行为、元分析与磁共振影像技术手段，试图全面地探索网络成瘾双系统的双重加工机制，进而为网络成瘾的预防与治疗提供更多的证据支持。本文共包括四个研究(6个实验)，分述如下:

研究一(实验1):该部分采用问卷调查手段采集了共416名青少年被试数据，利用结构方程模型分析方法评估奖赏/惩罚敏感性与冲动性对青少年网络成瘾的影响，以及个体的应对方式(情绪指向与问题指向)在其中的中介作用和性别的调节作用。结果发现，在女性中，具有高惩罚敏感性和高冲动性的个体患网络成瘾的风险更高，而在男性中，具有高奖赏敏感性和高冲动性的个体患网络成瘾的风险更高。此外，个体的应对方式在奖赏/惩罚敏感性、冲动对网络成瘾的影响中起到中介调节作用，且该中介效应存在性别差异。该部分从双系统人格特质角度出发，揭示了青少年网络成瘾易感因子的性别差异及其内在作用机制。

研究二(实验2):该部分进一步细分网络成瘾人群，主要关注网游成瘾人群。该部分为行为学实验，共招募了45名来自成瘾治疗中心的青少年网游成瘾被试和43名匹配的健康被试，应用混合赌博任务和Stop-Signal任务分别考查网游成瘾人群的风险决策(损失规避倾向)和抑制控制能力。结果发现，和健康被试相比，网游成瘾被试存在更弱的损失规避倾向和更差的抑制控制能力，且进一步的聚类分析发现，该双系统的异常只存在于成瘾程度更高的网游成瘾被试中而成瘾程度较低的被试则只存在更弱的损失规避而其抑制能力相对完好。

研究三(实验3) :该部分采用元分析技术对以往行为成瘾和物质成瘾奖赏和认知控制系统方面的脑影像研究进行量化总结，以考查成瘾双系统的神经基础。结果发现，成瘾人群在纹状体、前扣带回嚎部等奖赏关键区域存在更强的激活模式，而认知控制方面，未发现成瘾人群的异常激活。进一步分析发现，行为成瘾异常的奖赏系统主要以纹状体的尾状核和苍白球的高激活为基础，而物质成瘾除尾状核呈高激活模式外，其前扣带回嚎部的高激活也是物质成瘾异常奖赏系统的主要神经基础。该部分使我们对以往成瘾双系统研究有了较为充分的了解，为后续网游成瘾双系统的神经基础研究奠定了良好的基础。

研究四(实验4-6): 实验4:该部分应用轮盘赌任务和Stop-Signal任务，并利用任务态功能磁共振影像技术共采集了28名大学生网游成瘾被试和匹配的28名健康被试的数据，以考查网游成瘾人群奖赏加工三个阶段(奖赏预期、结果监控和选择评价)和认知控制的神经基础。结果发现，和健康被试相比，网游成瘾被试在奖赏预期和结果监控阶段均表现出纹状体区域(伏隔核、尾状核)更强的激活模式，这与研究三结果部分相符。抑制控制方面，与研究二聚类结果相符，只在成瘾程度较高的被试中发现了抑制控制关键脑区(额下回)的低激活。实验5:该部分利用静息态功能磁共振影像技术，以考查网游成瘾人群双系统间的功能性连接。被试样本与实验4相同。结果发现，和健康被试相比，网游成瘾被试在纹状体和额下回等前额叶控制区域的连接上表现更弱。实验6:该部分利用结构磁共振影像技术，以考查网游成瘾人群双系统的结构异常。被试样本与实验4相同。结果发现，和健康被试相比，网游成瘾被试仅在纹状体区域的灰质体积更大，而控制相关区域无结构异常。

上述四个研究从双系统角度出发，研究一揭示了不同性别网络成瘾的易感因子及其内在作用机制;研究二至研究四表明，增强的奖赏系统是网游成瘾个体中较为稳定的特征，个体增强的奖赏系统在网游成瘾的发展和维持中起关键作用，而不足的抑制控制与成瘾个体的严重程度密切相关，共同揭示了网游成瘾个体奖赏和认知控制系统的失衡关系。本文的研究发现为网络成瘾，尤其是网游成瘾的预防和干预提供了重要启示。

Internet addiction (IA) refers to one's inability to control the strong desire to use the Internet, which eventually leads to impairments in psychological, social and educational/work. In the past decade, IA has become more and more serious due to its entertainment and accessibility, especially among teenagers and college students. Internet gaming disorder (IGD), one of the subcategories of IA, has been classified as a mental disorder by the fifth edition of the diagnostic and statistical manual of mental disorders and the eleventh edition of the international classification of diseases. Based on the dual-system of adolescent neurobiological model and self-regulation model, the present paper aimed to explore the psychological and brain mechanisms of the reward and cognitive control system in IA by applying the questionnaire survey, behavior, meta-analysis and magnetic resonance imaging (MRI) technology, and thus provide more evidence for the prevention and treatment of IA. This paper consists of four studies (six experiments), which are stated as follows:

Study 1 (experiment 1):this study collected a total of 416 adolescents data by adopting the questionnaire survey method, and then evaluated the relationship between reward/punishment sensitivity, impulsivity and IA in adolescents, and the mediating roles of coping styles (emotion-focus and problem-focus) and gender among this relationship by using the structural equation model analysis method. The results showed that in boys, individuals with high reward sensitivity and impulsivity had a higher risk of IA, while in girls, individuals with high punishment sensitivity and impulsivity had a higher risk of IA. And individual coping styles played a mediating role in the relationship between reward/punishment sensitivity, impulsivity and Internet addiction, which were gander differences. From the personality traits of dual system perspective, this study revealed the gender difference in the risk factors of IA and its mediating mechanisms.

Study 2 (experiment 2): this study mainly focuses on the IGD population, the most serious subtype of IA. The study is a behavioral experiment, in which a total of 45 adolescents with IGD from an addiction treatment center and 43 matched healthy controls (HCs) were recruited. The mixed gambles task and the stop-signal task were used to explore the risky decision-making (loss aversion) and inhibition control ability in IGD. The results showed that compared with HCs, subjects with IGD had reduced loss aversion and worse inhibitory control ability, and the cluster analysis found that the dysfunctions of the dual-system were only observed in subjects with higher severity of IGD, whereas subjects with relatively lower severity of IGD only showed reduced loss aversion but intact inhibition ability.

Study 3 (experiment 3): this study used the meta-analysis to summarize the previous brain imaging studies on reward and cognitive control system of behavior addiction and substance addiction to examine the neural substrates of the dual-system in addiction. The results showed that the addicted population exhibited stronger activation patterns in brain regions crucial for reward (the striatum and rostral anterior cingulate gyrus), while no consistent abnormalities in cognitive control were found. Further, we found that the dysfunctional reward system of behavior addiction was mainly located on caudate nucleus and pallidum of striatum, which showed strong activation pattern. The dysfunctional reward system of substance addiction located on the rostral anterior cingulate gyrus and caudate, which also showed strong activation pattern. Through this study, we have a sufficient understanding of previous studies on dual-system of addiction, which provides a good foundation for the follow-up investigation of the neural substrates in IA.

Study 4 (experiment 4-6): experiment 4: this part aimed to investigate the neural substrates of reward processing's three phases (reward anticipation, outcome monitoring and choice evaluation) and cognitive control in IGD by applying task-state functional MRI. We recruited 28 college students with IGD and matched 28 HCs. All subjects completed the roulette task and the stop一signal task under functional magnetic resonance imaging scanning. The results showed that compared with HCs, subjects with IGD showed stronger activation patterns in the striatum region (nucleus accumbens, caudate) during the reward anticipation and outcome monitoring phase, which is partly consistent with the findings of study 3. In terms of inhibitory control, consistent with the cluster results of study 2, insufficient activation of in inhibitory control-related region (inferior frontal gyrus) was only found in subjects with high severity of IGD. Experiment _5:this part aimed to investigate the functional connectivity between reward and cognitive control systems in IGD by applying resting-state functional MRI. The sample of the current experiment was same as that of experiment 4. The results showed that compare with HCs, subjects with IGD exhibited weaker functional connectivity between striatum and prefrontal control regions (inferior frontal gyrus and superior frontal gyrus). Experiment 6: this part aimed to investigate the structural alteration of reward and cognitive control systems in IGD by applying structural MRI. The sample of the current experiment was same as that of experiment 4. The results showed that compare with HCs, subjects with IGD only exhibited larger gray matter volume in striatum.

From the perspective of dual-system, the current study 1 revealed the different risk factors among genders and the underlying mechanism, study 2, 3 and 4 suggest that the enhanced reward system is a more stable feature of IGD, and enhanced reward system plays a key role in the development and maintenance of IGD, while the insufficient inhibitory control is related to the severity of IGD, which jointly revealed the imbalance between reward and cognitive control system in IGD. In sum, all these findings might provide important implications for the prevention and intervention of IA, especially IGD.