This project achieved its aims in that we were able to recruit a large sample of children (N = 265; 6-13 years) to take part in an 8-week training regime of either cognitive control or response speed, and an extensive battery of behavioral and neural assessments before and after the training as well as at 1-year follow-up. The sample was only 10% less than what had been originally proposed, most likely due to Covid-19 and associated restrictions taking place during the recruitment and testing phase. Pivoting to online testing allowed for retention of already recruited participants as well as recruiting a small number of additional participants. With the baseline data we were able to study a range of questions and looked at age-related changes in specific outcome measures that were designed to probe cognitive control (Thompson & Steinbeis, 2020; Smid et al., 2023a, 2023b; Ganesan & Steinbeis, 2021). Crucially, we were able to test whether our training led to any changes across our comprehensive battery of outcome measures. We found that with exception of very closely related tasks, there was no specific effect of cognitive control training on any behavioral or neural outcome measures either immediately or one year after training. Bayesian tests provided overwhelming evidence in support of absent training effects (Ganesan et al., 2024). We did find some specific effects of training on variability in the trained cognitive processes for each group (Canigueral et al., 2023). This work has spawned a host of theoretical papers advocating for a shift away from attempts to train cognitive capacity towards targeting meta-level components of when to engage in cognitive control (Ganesan & Steinbeis, 2021; Steinbeis, 2023).
