Zaki, J. | bioRxiv Science

bioRxiv2020

Conservative and liberal attitudes drive polarized neural responses to political content

People tend to interpret political information in a manner that confirms their prior beliefs, a cognitive bias that contributes to rising political polarization. In this study, we combined functional magnetic resonance imaging with semantic content analyses to investigate the neural mechanisms that underlie the biased processing of real-world political content. We scanned American participants with conservative-leaning or liberal-leaning immigration attitudes while they watched news clips, campaign ads, and public speeches related to immigration policy. We searched for evidence of "neural polarization": activity in the brain that diverges between people who hold liberal versus conservative political attitudes. Neural polarization was observed in the dorsomedial prefrontal cortex (DMPFC), a brain region associated with the interpretation of narrative content. Neural polarization in the DMPFC intensified during moments in the videos that included risk-related and moral-emotional language, highlighting content features most likely to drive divergent interpretations between conservatives and liberals. Finally, participants whose DMPFC activity closely matched that of the average conservative or the average liberal participant were more likely to change their attitudes in the direction of that groups position. Our work introduces a novel multi-method approach to study the neural basis of political cognition in naturalistic settings. Using this approach, we characterize how political attitudes biased information processing in the brain, the language most likely to drive polarized neural responses, and the consequences of biased processing for attitude change. Together, these results shed light on the psychological and neural underpinnings of how identical information is interpreted differently by conservatives and liberals. Significance StatementPartisan biases in processing political information contribute to rising divisions in society. How do such biases arise in the brain? We measured the neural activity of participants watching videos related to immigration policy. Despite watching the same videos, conservative and liberal participants exhibited divergent neural responses. This "neural polarization" between groups occurred in a brain area associated with the interpretation of narrative content, and intensified in response to language associated with risk, emotion, and morality. Furthermore, polarized neural responses predicted attitude change in response to the videos. These findings suggest that biased processing in the brain drives divergent interpretations of political information and subsequent attitude polarization.

neuroscience↗

bioRxiv2018

Neurocomputational mechanisms underlying motivated seeing

People tend to believe their perceptions are veridical representations of the world, but also commonly report perceiving what they want to see or hear, a phenomenon known as motivated perception. It remains unclear whether this phenomenon reflects an actual change in what people perceive or merely a bias in their responding. We manipulated the percept participants wanted to see as they performed a visual categorization task for reward. Even though the reward maximizing strategy was to perform the task accurately, this manipulation biased participants perceptual judgments. Motivation increased activity in voxels within visual cortex selective for the motivationally relevant category, indicating a bias in participants neural representation of the presented image. Using a drift diffusion model, we decomposed motivated seeing into response and perceptual components. Response bias was associated with anticipatory activity in the nucleus accumbens, whereas perceptual bias tracked category-selective neural activity. Our results highlight the role of the reward circuitry in biasing perceptual processes and provide a computational description of how the drive for reward can lead to inaccurate representations of the world.

neuroscience↗

bioRxiv2018

Wanting to like: Motivation influences behavioral and neural responses to social feedback

Human beings revel in social approval and social connection. For example, individuals want to be liked, and frequently surround themselves with people who provide such positive reinforcement. Past work highlights a \"common currency\" between social rewards like social approval, and non-social rewards like money. But social and motivational contexts can reshape reward experiences considerably. Here, we examine the boundary conditions that deem social approval subjectively valuable. Participants received feedback about their attractiveness from others. Neural activity in reward-related brain structures (e.g., ventral striatum) increased in response to positive feedback, but only when such feedback came from well-liked targets. These heightened reward responses predicted increases in subsequent attraction to well-liked targets. This work suggests that motivational contexts amplify or diminish the value of social approval in a target-specific manner. The value of social approval is thus defined by the extent to which these experiences bring us closer to people we like.

neuroscience↗