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

ABSTRACT

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.

Acknowledgments

The views, opinions, and/or findings contained in this article are those of the authors and should not be interpreted as representing the official views or policies, either expressed or implied, of DARPA or the Department of Defense. Additionally, we received support from the National Institutes of Health in form of a New Innovator Award (NIH 1DP2DA03515601; PI Falk). We gratefully acknowledge Alixandra Barasch and Jonah Berger for fruitful discussions during earlier stages of this work and the Communication Science Laboratory for research assistance during data collection and analysis.

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes

1. Note that a larger sample of participants was screened for participation in this study. Forty-three participants were chosen based on the ego-betweenness centrality of their Facebook networks in order to answer a research question that is orthogonal to the analyses discussed here (see the online pre-registration document for details; authors redacted, 2015).

2. As noted on neurosynth.org: “Reverse inference map: z-scores corresponding to the likelihood that a term is used in a study given the presence of reported activation (i.e., P(Term|Activation))”, in other words reverse inference maps illustrate brain regions where activation is associated with the specified function.

Additional information

Funding

This work was supported by the Defense Advanced Research Projects Agency [D14AP00048]; National Cancer Institute [1DP2DA03515601]; ARL [Cooperative Agreement Number W911NF-10-2-0022; Subcontract Number APX02-0006] and Hopelab.