The aim of this study is to analyze the effect of the working memory training with CogMed on trained and not directly trained cognitive abilities and on the changes in cortical electrophysiological reorganization during the sleep after training. The sleep analysis will be focused in particular on the slow waves activity [frequency range of 1-4.5 Hz] and on the sleep spindle [frequency range of 12-14Hz], which reflect the depth of sleep and are related to memory processes, learning and brain plasticity.