To our knowledge, this is the first experimental research to clarify the behavioral and neural correlates of self-serving bias in participants with IGD and RGU. A modified self-serving bias task was adopted to examine how they made causal attributions in game world and real world contexts. At the behavioral level, the individuals with IGD exhibited an attenuated self-serving bias with a relatively diminished self-protection and self-enhancement, which was consistent with our hypotheses. At the neural level, the IGD group demonstrated increased vmPFC activation during attributing negative events compared to RGU in both contexts, and the IGD participants with higher vmPFC activation showed a lower level of self-protection; meanwhile, in the IGD group relative to RGU, decreased precuneuspcc activation was found during attributing positive events in real world, and the positive correlation between precuneus activation and attribution rating scores of self-related positive events was reduced.
In the development process of human life, individuals spontaneously strive to understand the world through attributing the cause of events and usually build an adaptive attributional pattern of self-serving bias (42). The RGU, as the normal controls, are inclined to connect valenced events with ‘plausible’ causes to foster a positive self-concept. However, a depressive pattern of self-serving bias was observed in IGD. That is, they made excessively internal attributions for negative events and external attributions for positive events, indicating the deficits in both self-protection and self-enhancement. Consistent with these findings, prior research has reported that the individuals with IGD are likely to be thwarted in attaining the identity formation and vulnerable to the negative feedback, which might substantiate the inabilities to find ways to discount such feedback and protect the self from threats (43, 44). Another study asked participants to rate how well the adjectives described themselves and discovered that IGD individuals rated themselves less positively than health controls, suggesting a lower level of motivation to maintain a favorable self-view in IGD (17). Moreover, especially during dealing with attributions of interpersonal events, the IGD participants evaluated themselves as having more negative traits and fewer positive traits, which has been proved to potentially exert a negative impact on interpersonal attitude formation (45). To some extent, it may further clarify why people with IGD cannot stay in good family and interpersonal relationships.
Additionally, the RGU reported high self-esteem and low depression, and there was a trend that those with relatively higher BDI score exhibited a higher motivation of self-protection. These may suggest that the RGU adopted various self-protective tactics to resist depressive symptoms and preserve positive self-view, further indicating that they were capable to adaptively regulate self-protective behavior. Unlike the RGU, the individuals with IGD reported low self-esteem and high depression. The behavioral results in our study also demonstrated that people with low self-esteem and high depression showed less self-serving bias, which were in line with previous work (20, 21). More interestingly, within IGD group, lower self-esteem was associated with a lower level of self-enhancement while higher BDI score was associated with a lower level of self-protection. It could be speculated that the individuals with IGD were less motivated to achieve gains for their self-esteem and easily perturbed by dysthymia without effectively protecting themselves from depressed mood. What’s more, these correlational findings suggested intriguing possibilities that self-esteem and depression, respectively, have predictive abilities to the motives of self-enhancement and self-protection. Correlation analysis also revealed an inverse relationship between depression and self-esteem in both groups, reflecting that people with low self-esteem were susceptible to depression (46). Hence, it is important to develop interventions that enhance self-esteem and reduce depression, especially for individuals with IGD.
Neurobiologically, the individuals with IGD showed increased brain activation in the vmPFC when assigning internal causes of negative valenced events. It is widely acknowledged that the vmPFC is commonly activated when individuals process self-relevant information (47, 48). More specifically, this region also plays a vital role in appraising and representing the personal value or significance of self-related contents during self-processing (49, 50). Thus, the increased vmPFC activation in IGD may imply additional endeavor in evaluating and judging the extent to which they viewed negative events as caused by themselves. However, the decreased motivation of self-protection the IGD participants exhibited, the increased cognitive endeavor they employed to evaluate negative valenced events. A possible interpretation for this phenomenon was that the gaming addicts could not protect their self-concept from negative information, which indicated a deficit in self-protective function in IGD. In addition, many studies have demonstrated that people with low self-esteem are particularly sensitive to negatively valenced information and devote more attentional resources to negative stimuli (51, 52). With this in mind, our current findings may also suggest that the people with IGD were oversensitive to negative self-related information and could not able to avoid negative self-evaluation, providing further evidence for the impaired self-protective ability in IGD.
Moreover, during attributing positive events, the IGD group exhibited decreased precuneuspcc activation as compared with RGU in the real world. The precuneuspcc have been proven to be involved in self-referential processing and causal attribution (27, 53). For example, the precuneuspcc was engaged during tasks which need to make specific judgements of self-relevant traits compared to self-irrelevant traits or attribute causes of social positive or negative events. More precisely, it is clearly evidenced that the anterior precuneuspcc (close to the part in our study) is implicated in internal attribution during the evaluation of positively valenced situation (30). What’s more, other study has found that individual variations in subjective core value ratings were tracked by the precuneuspcc, indicating the extent to which a value was perceived as internalized part of a person’s self-concept (54). Therefore, the lower precuneuspcc activation in facing positive events may be explained by the intrinsic characteristic of assigning less positive subjective value to self-related information, on which the individuals with IGD based their actions (less internal attributions for positive events). Furthermore, we found a reduced positive correlation between activation in the precuneuspcc and attribution ratings of positive events in IGD group in real world, which also revealed that the individuals with IGD tended to view themselves in less positive terms and lower their standing on positive traits.
In all, the attenuated self-serving bias in IGD were germane to the aberrant functioning of CMS regions critically implicated in self-related processing. Furthermore, in view of the negative attitude toward self-concept for individuals with IGD, future studies should adopt strategies to improve and protect their self-esteem and maintain positive self-concept. Early studies have detected that the self-affirmation interventions can bring about an expansive view of the self and sustain the self-integrity, and also have lasting benefits in education, health and relationships (55), which may be an effective strategy to buffer the people with IGD against negative self-view.