PT - JOURNAL ARTICLE AU - Ralf Schmälzle AU - Matthew Brook O’Donnell AU - Javier O. Garcia AU - Christopher N. Cascio AU - Joseph Bayer AU - Danielle S. Bassett AU - Jean Vettel AU - Emily B. Falk TI - Brain connectivity dynamics during social interaction reflect social network structure AID - 10.1101/096420 DP - 2016 Jan 01 TA - bioRxiv PG - 096420 4099 - http://biorxiv.org/content/early/2016/12/23/096420.short 4100 - http://biorxiv.org/content/early/2016/12/23/096420.full AB - Social ties are crucial for humans. Disruption of ties through social exclusion has a marked effect on our thoughts and feelings; however, such effects can be tempered by broader social network resources. Here, we use functional magnetic resonance imaging data acquired from 80 male adolescents to investigate how social exclusion modulates functional connectivity within and across brain networks involved in social pain and understanding the mental states of others (i.e., mentalizing). Furthermore, using objectively logged friendship network data, we examine how individual variability in brain reactivity to social exclusion relates to the density of participants’ friendship networks, an important aspect of social network structure. We find increased connectivity within a set of regions previously identified as a mentalizing system during exclusion relative to inclusion. These results are consistent across the regions of interest as well as a whole-brain analysis. Next, examining how social network characteristics are associated with task-based connectivity dynamics, participants who showed greater changes in connectivity within the mentalizing system when socially excluded by peers had less dense friendship networks. This work provides novel insight to understand how distributed brain systems respond to social and emotional challenges, and how such brain dynamics might vary based on broader social network characteristics.