Page 125 - Like me, or else... - Michelle Achterberg

Longitudinal changes of brain and behavior
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intervention (Euser et al., 2016). Using linear mixed effects modeling, we first investigated how behavioral aggression after positive, negative and neutral social feedback changed over time, and whether variation in the environment influenced these changes. Next, we investigated changes in brain responses related to positive, negative and neutral social feedback longitudinally within childhood and examined brain-behavior associations. Based on previous studies, we selected the AI, the IFG, the MPFC, and DLPFC as regions of interest (Gunther Moor et al., 2010b; Vijayakumar et al., 2017; Achterberg et al., 2018b). To test individual differences in aggression regulation we additionally performed exploratory whole brain-behavior MRI analyses to test for relations between prefrontal cortex activation and aggression regulation.
Methods
Participants
Participants in this study took part in the longitudinal twin study of the Leiden Consortium on Individual Development (L-CID (Euser et al., 2016)). The procedures were approved by the Dutch Central Committee Human Research (CCMO) and written informed consent was obtained from both parents. 512 children (256 families) between the ages 7 and 9 were included at the first wave (previously described in Achterberg et al. (2018b), van der Meulen et al. (2018)), with a mean age of 7.94 ± 0.67 (49% boys, 55% monozygotic). The majority of the sample was Caucasian (91%) and right-handed (87%). Ten participants (2%) were diagnosed with an Axis-I disorder: eight with attention deficit hyperactivity disorder (ADHD); one with generalized anxiety disorder (GAD), and one with pervasive developmental disorder- not otherwise specific (PDD-NOS). Intelligence (IQ) was estimated at W1 with the subtests ‘similarities’ and ‘block design’ of the Wechsler Intelligence Scale for Children, third edition (WISC-III; Wechsler, 1997). Estimated IQs were in the normal range (72.50 - 137.50). 456 children participated in a second lab two years later (for details regarding participant dropout see Figure S1 and supplementary materials). Table 1 provides an overview of demographic characteristics of the sample at wave 1 (W1) and wave 2 (W2). Participants underwent an MRI scan as part of the lab visits. At W1, 385 participants were included in the MRI analyses (mean age 7.99 ± 0.68, 47% boys, see also Achterberg et al. (2018b)). At W2 360 participants were included in the MRI analyses (mean age 10.01 ± 0.67, 48% boys). A total of 293 participants were included on the MRI analyses at both waves (mean age W1: 7.99 ± 0.66, 47% boys).
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