Page 202 - Like me, or else... - Michelle Achterberg

Chapter 7
consisted of child appropriate texts and illustrative pictures. The lab visit took place at the Leiden University Medical Centre (LUMC) and consisted of four components: the MRI preparation session, the MRI scan session, parent-child interaction tasks, and a child behavioral tasks session. In the current study, data from the MRI preparation session and the MRI scan session were evaluated. During the practice session the whole family was further introduced to the aims of the study, and carefully instructed about safety around the MRI system and the influence of motion on the scans. Next, the children participated in a MRI simulation with the MRI researcher. In the MRI simulation, the exact same steps that were also explained in the step-by-step explanation were followed. A prototype of a Philips scanner (without a working magnet) was used to mimic the MRI environment. Children listened to MRI sounds via a laptop. They were shown the various materials (e.g. headphones, button box, coil with mirror attached) for the MRI procedure. Next, they were asked to practice lying very still on the scanner bed while wearing the headphones and button box. Finally, they practiced looking in the mirror on the coil, while they were slowly slid into the MRI bore. After the MRI simulation, the children were familiarized with the MRI tasks on a laptop. First-born and second-born children of each twin pair were randomly assigned to the MRI scan session or to the parent-child interaction tasks as their first activity. There were no differences in outcome measures (scanner related distress, scan quantity or scan quality) for children that were scanned directly after the MRI simulation or an hour later.
The MRI session lasted 60 minutes, including two fMRI tasks, high resolution T2 and T1 scans, diffusion tensor imaging (DTI) scans and a resting state (RS) fMRI scan. The first fMRI task was the Social Network Aggression Task (SNAT), as described in detail in Achterberg et al. (2018b). In short, participants viewed pictures of peers that gave positive, neutral or negative feedback to the participant’s personal profile. Next, participants could blast a loud noise towards the peer as an index of aggression. The SNAT consisted of 3 runs of approximately 5 minutes each. The second task was the Prosocial Cyberball Game (PCG), as described in detail in van der Meulen et al. (2018). In short, participants were instructed to participate in a virtual ball tossing game with three other players. During the game, two of the other players excluded the third player. The participant could choose to compensate for this exclusion by tossing the ball more often to the excluded participant (prosocial compensating behavior). The PCG consisted of 2 runs of approximately 5 minutes each. After the fMRI tasks participants watched a self-chosen child-friendly movie during the structural anatomical scan (3DT1) and the structural connectivity scans (DTI). The scan session ended with a RS fMRI scan, in which participants were instructed to lay still with their eyes closed and not to fall asleep (for details, see Achterberg et al. (2018a)). The order of the scans was the same for all participants and always started with the SNAT fMRI task, followed by the PCG fMRI task, the 3DT1, DTI and the RS fMRI.
200