Procedure and controlled environment
The intervention of this trial took place over five days during which the subjects were accommodated in a controlled environment. This was necessary to prevent distraction and reproduce the same environment for all subjects. Both the control and the intervention group stayed in a hostel in Jena (Germany) for 5 days and 4 nights. We established a set of behavioural rules for the controlled environment. Adherence to those rules was checked regularly, randomly, and unannounced multiple times per day throughout the trial by members of the study team. There were no major violations of these rules. We tested the viability of our procedure with eight subjects in a pilot trial and optimized it afterwards. The data of these subjects are not included in the analysis. All subjects were allowed to spend 90 min each day outside the hostel. Any physical activity (like Walking, Jogging, Yoga, etc.) had to be performed in this time window. The performed physical activity was not allowed to exceed the usual extent of the individual. The physical activity was recorded and monitored. For the rest of the time, they had to stay either in their rooms, the common room, or in the lounge areas of the hostel. Smartphone or cell phone use was allowed for only 30 min a day, however talking via phone was possible without restriction. The following activities were not allowed for any of the groups: playing video games, learning new motor skills like juggling, or knitting, consuming drugs of any kind (except cigarettes) and using touch-typing outside of training times while handwriting was allowed. All subjects had to record their activities and times of absence. All participants shared the same meals and mealtimes. The intervention group had to consume eight hours of visual media content (i.e., television or video-on-demand-services) of their choice accumulatively per day in a passive posture (i.e., sitting or lying). The intervention group had to keep record of their watched media content (e.g., genres of watched content, duration). The control group was allowed to perform all usual leisure-time activities, which were not new to them neither included screen time. Most participants choose reading, board games, and cooking.Every day at the same time in the morning and in the afternoon, there was a 45-min grouped and supervised training session in touch-typing for the participants (see next section for more details), resulting in 90 min of training per day. The day before and the day after leaving the controlled environment, each subject underwent assessment (pre and post) for data acquisition. For the exact pattern of our trial procedure please refer to 