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

The rapid spread of misinformation during the COVID-19 pandemic has raised importantquestions about how individuals process misinformation, particularly in contexts where priorbeliefs are already strongly held. This study used functional magnetic resonance imaging (fMRI)to examine the neural mechanisms involved in evaluating COVID-19 vaccine misinformationand 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 ourhypotheses, we did not observe significant involvement of emotional processing regions such asthe amygdala or precuneus when participants were exposed to vaccine-related misinformationthat conflicted with their prior-held beliefs. However, when participants made belief-incongruentresponses (i.e., endorsing misinformation or rejecting accurate information) we observedincreased activation in the left dorsolateral prefrontal cortex (DLPFC), dorsomedial prefrontalcortex (DMPFC), intraparietal sulcus (IPS), and middle frontal gyrus (MFG)—regionsimplicated in decision-making, moral reasoning, memory integration, and cognitive control. Ourfindings suggest that resolving conflicts between incoming information and prior beliefs engageseffortful decision-making systems that battle uncertainty and conflict. Due to recruitmentlimitations, the present analysis was restricted to vaccine-adherent individuals. Future researchshould explore whether vaccine-resistant individuals show similar or distinct neural responseswhich may provide more insight into the persistence of misinformation in the context of negativeprior beliefs.