Page 136 - Like me, or else... - Michelle Achterberg
P. 136

                                Chapter 5
 Discussion
There is a great need to have a better understanding of the mechanisms that drive changes in emotion regulation during social interactions across childhood. The current study tested the neural signature of aggression regulation in childhood in the context of social evaluations, specifically social acceptance and social rejection. For this purpose, we made use of the unique longitudinal L-CID cohort, which allowed us to examine the development of aggression regulation within individuals over time and take into account possible effects of genetics and environmental variations. By using longitudinal behavioral-neural comparisons, we were able to address the question how change in neural activity relates to change in behavioral development. The current study revealed three main findings: 1) behavioral aggression after social evaluation decreased over time, and this decrease was most pronounced for aggression after positive and neutral social feedback; 2) confirmatory ROI analyses showed that increased activity in AI was related to more aggression, whereas increased activity in DLPFC was correlated with less aggression; and 3) bilateral DLPFC was correlated to less subsequent aggression following negative social feedback. Longitudinal comparisons confirmed that a larger increase in DLPFC activity across childhood was related to a larger decrease in behavioral aggression after negative social feedback.
The behavioral results confirmed our initial hypothesis that behavioral aggression decreases over time, consistent with prior reports on age related increases in behavioral control (Diamond, 2013; Casey, 2015). Interestingly, however, these reductions in aggression were most pronounced following positive and neural feedback, suggesting that participants were more motivated to refrain from aggression towards liked others. These findings fit well with research showing that the importance of being liked and accepted by others increases over the course of childhood and into adolescence (Rodman et al., 2017; Sherman et al., 2018a). Thus, with increasing age, children become more focused on refraining punishment towards people with whom they socially connect and they differentiate more between liked (individuals signaling social acceptance) and disliked (individuals signaling social rejection) others (see also Guroglu et al. (2014)).
By using functional neuroimaging we were able to address the neural correlates following social evaluation feedback across two time points. Consistent with prior reports (Achterberg et al., 2018b), children activate the same network across two waves, with stronger activity in ACC, AI and IFG after both positive and negative social feedback (relative to neutral feedback). These findings fit well with results from the adult literature, showing that neural activation in ACC, AI, and IFG, is associated with social rejection (Eisenberger et al., 2003; Cacioppo et al., 2013)) and signaling social salient events (Dalgleish et al., 2017). The DLPFC, in contrast, was more active for positive than
 134





























































































   134   135   136   137   138