Page 124 - Like me, or else... - Michelle Achterberg

Chapter 5
increased activation in the dACC and AI was related to less aggression in adults with high executive functioning, whereas adults with low executive functioning showed increased aggression with increasing neural activation (Chester et al., 2014). Prior studies in adults further showed that the dorsolateral prefrontal cortex (DLPFC) might serve as a regulating mechanism for aggression after social evaluation, such that increased DLPFC activity after social rejection was related to less behavioral aggression (Riva et al., 2015; Achterberg et al., 2016b). Moreover, stronger functional connectivity between the lateral PFC and limbic regions was related to less retaliatory aggression (Chester and DeWall, 2016). Interestingly, prior theoretical perspectives have suggested that DLPFC maturation is an important underlying mechanism for developing a variety of control functions in childhood (Bunge and Zelazo, 2006; Diamond, 2013). Prior research revealed that in 7-8 year old children there were indications for associations between DLPFC and behavioral aggression(Achterberg et al., 2018b), although these were less pronounced than in adults. Taken together, studies in adults showed a link between cognitive control and regulation of emotions after rejection in the ACC/insula (Chester et al., 2014) and DLPFC (Achterberg et al., 2016b), but no study to date examined longitudinal developmental changes in these brain regions in childhood in the context of social evaluation. These prior studies led us to hypothesize that within-person maturation of the ACC/AI and DLPFC may be associated with better aggression regulation in childhood.
The current study makes use of a unique developmental twin sample of the Leiden Consortium for Individual Development (L-CID; Euser et al. (2016)). The design is based on recent insights showing that home environment is an important factor that impacts children’s behavioral control (Sektnan et al., 2010; Vrijhof et al., 2018). The L-CID study makes use of the video feedback intervention to promote positive parenting and sensitive discipline (VIPP-SD), an attachment based intervention that aims to enhance parental sensitivity and sensitive discipline (Juffer et al., 2017a). The VIPP-SD has proven to diminish externalizing behavior problems such as aggression in younger age groups (0-6 years (Van Zeijl et al., 2006; Juffer et al., 2017b)). The L-CID study tests whether the VIPP-SD is also effective in parents with older children and possibly likewise beneficial for behavioral outcomes of older children. Therefore, this study design allows us to not only examine the development of aggression regulation within individuals over time, but also the effect of genetics and variations in the social environment.
Using this unique study design, we address the following research questions: i) How does aggression regulation following social evaluation changes longitudinally within childhood? And ii) to what extent are these changes dependent on heritability and changes in the social environment? In doing so, 492 same-sex twins (246 families) underwent two fMRI sessions across the transition from middle childhood (7-9 years) to late childhood (9-11 years). In between fMRI sessions, families received either the VIPP-Twins or a dummy
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