Article summary of Longitudinal changes in DLPFC activation during childhood are related to decreased aggression following social rejection by Achterberg et al. - 2020 - Chapter

Bullet point summary:

• Regulating aggression after social feedback is an important pre-requisite for developing and maintaining social relations, especially in the current times with larger emphasis on online social evaluation.
• Studies in adults highlighted the role of the dorsolateral prefrontal cortex (DLPFC) in regulating aggression. Little is known about the development of aggression regulation following social feedback during childhood, while this is an important period for both brain maturation and social relations.
• The current study used a longitudinal design, with 456 twins undergoing two functional MRI sessions across the transition from middle (7 to 9 y) to late (9 to 11 y) childhood. Aggression regulation was studied using the Social Network Aggression Task.
• Behavioral aggression after social evaluation decreased over time, whereas activation in the insula, dorsomedial PFC and DLPFC increased over time.
• Brain–behavior analyses showed that increased DLPFC activation after negative feedback was associated with decreased aggression. Change analyses further revealed that children with larger increases in DLPFC activity from middle to late childhood showed stronger decreases in aggression over time.
• These findings provide insights into the development of social evaluation sensitivity and aggression control in childhood.

When do children develop emotion regulation skills?

Regulating emotions during social interactions is one of the most important requirements for developing social relationships in childhood. With increasing age, children become better at regulating their emotions. Even though several studies have examined regulation processes in the context of social evaluation in adolescence, few studies have investigated the development of social emotion regulation during childhood. The current study builds upon new insights in the neural processing of social emotion regulation by examining change in neural and behavioral social control in a longitudinal functional MRI (fMRI) study in middle-to-late childhood.

What does social evaluation entail?

Neuroimaging research has shown that the significance of social evaluation is deeply rooted in our brain. Social evaluation, including social acceptance and rejection, has previously been studied using ecologically valid social judgment paradigms. It is well documented that social rejection can lead to ag- gression and retaliation. Controlling emotions elicited by social evaluation feedback relies on cognitive control, that is, individuals with better cognitive control functions show less aggression following rejection. Increased activation in the dorsal ACC and AI was related to less aggression after social rejection in adults with high executive functioning, whereas adults with low executive functioning showed increased aggression with increasing neural activation. 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. Interestingly, prior theoretical perspectives have suggested that DLPFC maturation is an important underlying mechanism for developing a variety of control functions in childhood. However, no study to date has examined longitudinal developmental changes in these brain regions in childhood in the context of social evaluation.

What did the current study measure?

The current study makes use of a developmental twin sample. This ongoing longitudinal twin study examines the development of social evaluation and behavioral control in 7- to 13-year-old children. The current study includes the first two fMRI assessments, separated by 2 years. Using linear mixed-effects modeling, it was first investigated how behavioral aggression after positive, negative, and neutral social feedback changed over time. Next, it was investigated changes in brain responses related to positive, negative, and neutral social feedback longitudinally and examined brain–behavior associations.

What were the findings of the current study?

The current study revealed three main findings:

• Behavioral aggression after social evaluation decreased over time, and this decrease was most pronounced for behavioral responses after positive and neutral social feedback.
• Confirmatory ROI analyses showed that increased activity in AI was related to more aggression following social feedback (regardless of its valence), whereas increased activity in DLPFC was correlated with less aggression.
• Bilateral DLPFC activity was correlated to less subsequent aggression following negative social feedback. Longitudinal comparisons confirmed that larger increases in DLPFC activity across childhood were related to larger decreases in behavioral aggression, in particular after negative social feedback.

The behavioral results confirmed the initial hypothesis that behavioral aggression decreases over time, consistent with prior reports on age related increases in behavioral control. Taken together, this study set out to test longitudinal changes in neural systems underlying social evaluation and aggression regulation and their relation to behavioral outcomes. We found an increase in behavioral control across childhood, as behavioral aggression decreased over time. Moreover, DLPFC activation was related to a decrease in behavioral aggression. Notably, children with larger increases in DLPFC activity across 2 years displayed the largest decrease in behavioral aggression over time. These results contribute to our understanding of how the developing brain processes social feedback and suggest that the DLPFC might serve as emotion regulation mechanisms in the context of negative social feedback.

What were the main conclusions of the current study?

The current study investigated 456 twins undergoing two functional MRI sessions across the transition from middle (7 to 9 y) to late (9 to 11 y) childhood. During this time, their behavioral aggression after social evaluation decreased, whereas activation in the insula, dorsomedial PFC and DLPFC increased over time. Brain–behavior analyses showed that increased DLPFC activation after negative feedback was associated with decreased aggression. Change analyses further revealed that children with larger increases in DLPFC activity from middle to late childhood showed stronger decreases in aggression over time.