Page 30 - Like me, or else... - Michelle Achterberg

Chapter 2
positive relative to negative feedback in older adolescents and adults (16-25) as indicated by increased activity in the ventral mPFC, the subcallosal cortex, and the ACC (Gunther Moor et al., 2010b). Another study found increased pupil dilation in response to social rejection (compared to acceptance) in children aged 9-17 (Silk et al., 2012). Pupil dilation is an index of increased activity in cognitive and affective processing regions of the brain, such as the ACC and amygdala (Silk et al., 2012), and the pupil becomes more dilated in response to stimuli with a greater emotional intensity (Siegle et al., 2003). Interestingly, the pupil dilation effect was larger for older participants, indicating that adolescents reacted more strongly to rejection than children. The current study examined the neural correlates of social evaluation in middle childhood, prior to adolescence, because the first long-lasting friendships gradually emerge around this time (Berndt, 2004). Furthermore, we tested whether peer rejection in children results in behavioral aggression, in a similar way as was previously observed in adults (Chester et al., 2014; Riva et al., 2015; Achterberg et al., 2016b).
Thus, our aim was to investigate 7-10-year-old children’s responses to social evaluation in terms of neural activity and reactive behavioral aggression. For this purpose, we used the Social Network Aggression Task (SNAT), that elicited robust neural and behavioral responses in adults (Achterberg et al., 2016b), but has not yet been used with children. During the SNAT, participants viewed pictures of peers who gave positive, neutral or negative feedback to the participant’s profile. Next, participants could deliver an imagined noise blast towards the peer, as an index of (imagined) aggression or frustration. Since recent studies have reported concerns about the replicability of psychological science (for example see Open Science (2015)), we used three samples to validate the paradigm: a pilot sample, a test sample, and a replication sample. Moreover, findings that may show no evidence of significance when analyzed individually might provide stronger evidence when collapsed across experiments, as was recently shown (Scheibehenne et al., 2016). Therefore we also include a meta- analytic combination of the results across the three samples.
On the behavioral level we expected that the pattern of aggression after positive, neutral, and negative feedback would be similar across the pilot, test and replication samples, with negative feedback resulting in the highest levels of aggressive behavior. On the neural level we examined both the general contrast of social evaluation (all feedback conditions vs. baseline; see Supplementary Materials) and the condition-specific contrasts. To further investigate condition effects, that is the effect of negative vs. neutral vs. positive feedback, we used regions of interest (ROI) analyses. The individual ROI analyses were meta- analytically combined in order to test for robust condition effects across our samples. Based on studies in adults, the predictions were that negative social feedback would be associated with increased activity in the amygdala (Masten et al., 2009), bilateral insula, and mPFC/Anterior Cingulate Cortex’ gyrus ACCg (Somerville et al., 2006; Achterberg et al., 2016b). While prior studies tested only
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