This report presents the methods from Tasks 4.4 and 4.5 that aim to elucidate impacts of ICT skills and use on adolescents’ wellbeing and cognitive and brain function in attention-demanding tasks. To this end, ESM and fMRI data collections were conducted in two countries: Belgium and Finland. In this report, we present the methods of data collection of these studies examining the short-term impacts of ICT use and skills on cognitive and psychological wellbeing. This report describes the conceptual definitions of the phenomena examined in this study, that is adolescents’ ICT use, wellbeing, and cognitive skills and related brain activity. We also describe the rationale for using the methods developed to study these phenomena. Moreover, the development and implementation of this methodology in the two studies is described.