Authority reliance vs. deliberative assessment in processing online rumors: evidence from fNIRS

This study aimed to clarify how the authority of a fact-checker shapes neurocognitive processing of online rumors. Specifically, this study examined differences in neural responses to corrections provided by authoritative and non-authoritative sources.

Functional near-infrared spectroscopy (fNIRS) was used to measure neural activity in the prefrontal cortex while participants evaluated information that had been fact-checked by either authoritative or non-authoritative third-party sources. Behavioral metrics, such as judgment accuracy, were collected alongside neural data to correlate brain activity with decision-making outcomes.

Authoritative fact-checkers produced stronger activation in the left prefrontal cortex (LPFC) and improved overall judgment accuracy, suggesting a cognitive "fast track" that facilitates information acceptance. This enhanced accuracy was accompanied by increased LPFC engagement, indicating deeper analytical engagement. For true information, non-authoritative fact-checking led to reduced right prefrontal cortex (RPFC) activation and only marginal behavioral improvements, suggesting participants relied on heuristic shortcuts or "cognitive offloading" rather than rigorous deliberation. During false information processing, RPFC activation decreased across specific channels (e.g., Ch19), with non-authoritative sources yielding higher false-information judgment accuracy (59%) compared to authoritative sources (55%). This paradoxical effect suggests that lower source credibility can, in certain contexts, elicit more vigilant evaluation of false claims. The neural and behavioral responses to authoritative versus non-authoritative sources varied based on information veracity, consistent with cognitive dissonance theory, which posits adaptive shifts in processing strategies in response to credibility cues.

By linking source credibility to distinct neural signatures and accuracy outcomes, this work provides a neurocognitive account of how fact-checker authority influences belief updating. The findings highlight that credibility cues can promote heuristic acceptance or more careful analysis, depending on the situation. Furthermore, this evidence can inform more effective rumor-intervention strategies that are sensitive to both source attributes and information type.