Neural responses to peer interactions in adolescents experiencing early life stress: an investigation of social exclusion and over-inclusion

• In Event: The consequences of adversity and maltreatment in brain function among adolescents and young adults

Abstract

Introduction: A well-documented literature outlines the adverse effects of early-life stress (ELS) on socioemotional behavior and risk for psychopathology (McLaughlin, 2018). Given pervasive negative outcomes, there is growing interest in identifying underlying mechanisms that may propagate the effects of ELS, and much attention has been directed towards the potential role of brain development (VanTieghem & Tottenham, 2018). However, minimal research has examined how adversity influences brain functioning associated with social processes, and existing studies focus solely on responses to negative social experiences. The current study investigated how early life stressors affect adolescents neural responses to both positive and negative social experiences using an adapted version of Cyberball, a virtual ball-throwing paradigm.

Method: 54 adolescents (11-17 years) in the child welfare system (i.e. currently in foster care) were recruited into the ELS group, and 70 non-separated adolescents (11-18 years) were recruited as controls. Participants completed a novel (event-related) fMRI adaptation of Cyberball. The task was comprised of two runs; one being over-inclusion (i.e. receiving more than an equal share of ball throws) and the other being exclusion (i.e. receiving less than an equal share of ball throws), with both runs randomly interspersed with periods of fair play. Parametric modulators were used to model BOLD response to an increasing number of consecutive trials of each condition (i.e. Increasing Inclusion and Increasing Exclusion). Statistical analyses examined group differences (ELS vs. controls) on each of these conditions, as well as the interaction between group and condition.

Results: Significant group differences in neural responses to Increasing Exclusion were present in the left lateral orbitofrontal cortex, right rostrolateral and dorsolateral PFC, and bilateral inferior occipital cortices. The ELS group exhibited increased activation within these clusters to consecutive exclusionary throws, while the control group showed the opposite pattern of response (see Figure 1). There was also a significant interaction between group and condition in predicting activation in the right intraparietal sulcus and temporo-occipital cortex. Post-hoc analyses revealed that this effect was driven by the ELS group exhibiting decreased activation to consecutive inclusionary throws relative to controls (see Figure 2).

Summary: The ELS group exhibited both greater response to exclusionary experiences, and reduced response to inclusionary experiences, relative to controls. Results for exclusion are consistent with prior findings of PFC hyperactivation during social exclusion in adolescents experiencing childhood maltreatment (van Harmelen et al., 2014) and chronic peer rejection (Will et al., 2016), suggesting that the ELS group may be engaging in greater affective decision-making and emotion regulatory processes. The novel finding of reduced activation to over-inclusion suggests that the ELS group may also differentially process positive social experiences. The intraparietal sulcus is part of a task positive dorsal attention network and has been implicated in the representation of others’ actions. In addition to visual processing within the temporo-occipital cortex, group differences may reflect reduced attentional processing of others during continued inclusionary events in the ELS group. Findings suggest that early life adversity may differentially influence neural processing of both positive and negative peer interactions during adolescence.

Authors

• Nandita Vijayakumar, Deakin University
  Presenting Author

• Theresa W Cheng, University of Oregon
  Non-Presenting Author

• John Coleman Flournoy, Harvard University
  Non-Presenting Author

• Jessica Flannery, University of North Carolina at Chapel Hill
  Non-Presenting Author

• Zdena A Op De Macks
  Non-Presenting Author

• Arian Mobasser, University of Oregon
  Non-Presenting Author

• Shannon Peake, University of Oregon
  Non-Presenting Author

• Philip Andrew Fisher, University of Oregon
  Non-Presenting Author

• Jennifer H. Pfeifer, University of Oregon
  Non-Presenting Author