No developmental fronto-parietal shift in brain activation during mental arithmetic across the lifespan: A registered report.

In a highly interconnected online information environment, public health topics are highly likely to attract widespread attention on social media platforms, as they directly concern the survival and safety of the public []. However, high levels of public attention are often accompanied by the fragmented dissemination of information and the proliferation of online rumors In discussions of such crisis topics, netizens show a distinct tendency to favor the spread of highly emotional information []. As information technology advances, digital emotion is defined as an emotional state conveyed and engaged with via digital media (e.g., text, emojis, multimedia) []. It is worth noting that social media platforms influence the contagion dynamics of digital emotions through multiple mechanisms. Existing research has shown that these mechanisms encompass at least the following three aspects: First, in pursuit of user engagement, social media platforms often manipulate information visibility through algorithms, artificially amplifying the frequency and intensity of users’ exposure to emotional content [].Next, the design of social features such as likes and comments lowers the threshold for emotional expression and contagion, while aggregation functions consolidate scattered emotional expressions into visible collective emotions []. Finally, the real-time interactive features provided by platforms create a sense of co-presence, prompting users to exhibit conformity and synchronization effects in emotional expression []. These platform-mediated intervention mechanisms, combined with the inherent immediacy and network structure of social media, not only accelerate the spread of health rumors but also give rise to the phenomenon of digital emotion contagion. Substantial evidence suggests that users’ emotional tendencies influence those of other users, thereby affecting netizens’ attitudes and subsequent behaviors toward health events on social media []. Digital emotion contagion on social media differs from face-to-face emotion contagion; it is a form of emotion contagion mediated by social media platform operators []. Therefore, investigating the mechanisms of digital emotion contagion in health-related emergencies has become a major practical challenge for current cyberspace governance. When health topics are widely discussed on social media, users are reluctant to invest additional time in verifying the authenticity of posts []. The spread of false news not only causes confusion but also provides incorrect advice, thereby misleading people’ s behavior and even endangering lives []. Does timely rumor refutation by public health authorities necessarily restore netizens’ digital emotions to a rational state? Existing research on the effectiveness of rumor refutation has primarily proceeded along three lines of inquiry, each of which has its own limitations. First, some scholars argue that official institutions, by providing accurate information, can correct erroneous cognitions to quell public opinion and curb the spread of negative emotions [,], even treating rumor refutation as the end point of emotional evolution []. However, this perspective overlooks the moderating role of emotional tone of content on user information processing in the social media context. Second, motivated reasoning suggests that people tend to accept information consistent with their own positions. When rumor refutation challenges existing cognition, it triggers defensive processing, leading individuals to reject or counter the corrective information []. The release of rumor refutation information may inadvertently reinforce the rumor by restating it, thereby strengthening people’s memory of the rumor and increasing their belief in it []. This is known as the backfire effect, which represents an extreme manifestation of motivated reasoning in specific contexts []. However, most experiments are conducted in controlled environments, leaving a gap in research on emotion contagion within real-world social networks. Third, research grounded in emotion contagion theory has confirmed that digital emotions spread among users through social networks []. However, these studies have not incorporated rumor refutation as a key intervention node into their analytical frameworks. In summary, the existing literature lacks an integrated theoretical explanation and empirical testing regarding the intersecting issue of digital emotion contagion pathways pre- and post-refutation interventions. At the methodological level, existing research on rumor refutation effectiveness has predominantly relied on regression analysis and experimental designs, focusing on identifying the net effect of single variables. Consequently, such approaches struggle to capture the equivalent pathways that may arise from the synergistic effects of multiple factors. Social phenomena are often driven by specific combinations of multiple conditions rather than by the linear superposition of sin