Neural Mechanisms of Cognitive Conflict: Processing COVID-19 Vaccine Misinformation

The rapid spread of misinformation during the COVID-19 pandemic has raised important questions about how individuals process misinformation, particularly in contexts where prior beliefs are already strongly held. This study used functional magnetic resonance imaging (fMRI) to examine the neural mechanisms involved in evaluating COVID-19 vaccine misinformation and factual information, with a focus on how prior beliefs shape these processes. Vaccine-adherent participants (N=39) were exposed to a series of vaccine-related statements—both accurate and false—and indicated their level of agreement during scanning. Contrary to our hypotheses, we did not observe significant involvement of emotional processing regions such as the amygdala or precuneus when participants were exposed to vaccine-related misinformation that conflicted with their prior-held beliefs. However, when participants made belief-incongruent responses (i.e., endorsing misinformation or rejecting accurate information) we observed increased activation in the left dorsolateral prefrontal cortex (DLPFC), dorsomedial prefrontal cortex (DMPFC), intraparietal sulcus (IPS), and middle frontal gyrus (MFG)—regions implicated in decision-making, moral reasoning, memory integration, and cognitive control. Our findings suggest that resolving conflicts between incoming information and prior beliefs engages effortful decision-making systems that battle uncertainty and conflict. Due to recruitment limitations, the present analysis was restricted to vaccine-adherent individuals. Future research should explore whether vaccine-resistant individuals show similar or distinct neural responses which may provide more insight into the persistence of misinformation in the context of negative prior beliefs.