Title: How Health Opinions Evolve under News and Social Influence

Abstract: How do social interactions and news exposure shape health-related opinions and behaviors, such as decisions about vaccination? To address this question, I will present a hybrid model of opinion dynamics on directed social networks in which individuals do not update continuously but instead accumulate evidence from socially filtered information and revise their opinions only when that evidence exceeds a threshold. 

This mechanism produces a rich variety of collective outcomes, including consensus, polarization and fragmentation, and these regimes can be organized in parameter space through interpretable controls of platform design, curation and user responsiveness. I will also discuss an extension that incorporates news media as a distinct external source with its own reach, attention level and receptivity. Motivated by vaccination and health information, this framework represents a step toward coupled information: epidemic models in which opinions influence behavior and epidemic prevalence feeds back into the information environment.