Neural correlates of maintaining one's political beliefs in the face of counterevidence

Abstract

People often discount evidence that contradicts their firmly held beliefs. However, little is known about the neural mechanisms that govern this behavior. We used neuroimaging to investigate the neural systems involved in maintaining belief in the face of counterevidence, presenting 40 liberals with arguments that contradicted their strongly held political and non-political views. Challenges to political beliefs produced increased activity in the default mode network-a set of interconnected structures associated with self-representation and disengagement from the external world. Trials with greater belief resistance showed increased response in the dorsomedial prefrontal cortex and decreased activity in the orbitofrontal cortex. We also found that participants who changed their minds more showed less BOLD signal in the insula and the amygdala when evaluating counterevidence. These results highlight the role of emotion in belief-change resistance and offer insight into the neural systems involved in belief maintenance, motivated reasoning, and related phenomena.

Figure 1. Behavioral results.

(A) Belief strength before and after counterevidence for political and non-political trials. (B) Belief change on political trials correlated with belief change on non-political trials across participants. (C) Response times for reading statements, reading challenges, and rating the strength of belief at the end of the trial. (D) Increased belief change was associated with higher ratings of the credibility of the challenging arguments.

Figure 2. Brain activation during challenges to political vs. non-political beliefs.

In red/yellow, brain regions that showed increased signal while processing challenges to political beliefs (P > NP). In blue/green, brain regions that showed increased signal during challenges to non-political beliefs (NP > P).

Figure 3. The relationship between belief change and brain activity.

(A) Across all stimuli, BOLD signal in orbitofrontal cortex during challenges correlated positively with amount of belief change. (B) Across all stimuli, BOLD signal in dorsomedial prefrontal cortex correlated negatively with amount of belief change. Scatter plots visualize the relationship found in the peak voxels in each region. (C) Stimulus items in order of average belief change.

Figure 4

BOLD signal during challenges correlated with belief change across participants in (A) dorsal anterior insular cortex and (B) amygdala, from region of interest analysis.