Decision-making about broad- and narrowcasting: A neuroscientific perspective

What differentiates sharing with few, well-defined others (narrowcasting) from sharing with loosely defined crowds (broadcasting)? One possibility involves a trade-off where broadcasting is self-focused and self-serving, and narrowcasting is based on other-oriented, altruistic motives. We present neuroimaging data consistent with a second, parallel-processes perspective. According to this account, both narrow- and broadcasting simultaneously involve self-related and social motives since these concepts are strongly intertwined both on a psychological and neural level. We recorded brain activity within regions that are meta-analytically associated with self-related and social cognition while participants made decisions to narrow- or broadcast New York Times articles on social media. Results show increased involvement of brain regions associated with both self-related and social processing in narrow- and broadcasting, compared to a control condition. However, both processes were involved with higher intensity during narrowcasting, compared to broadcasting. These data help to disambiguate a theoretical discussion in communication science and clarify the neuropsychological mechanisms that drive sharing decisions in different contexts. Specifically, we highlight that narrow- and broadcasting afford differing intensities of two psychological processes that are crucial to persuasion and population-level content virality.