Few studies in PD have focused on cognitive training and its neural correlates. A meta-analysis by Leung et al. (2015) showed positive effects of cognitive training on mainly 'frontal' cognitive functions (i.e. working memory, executive functions, processing speed). In addition, earlier research has described a neuroprotective effect of cognitive training on the development of MCI in PD (odds ratio: 3; Petrelli et al., 2015). Until now, however, studies have been relatively small and mainly without a controlled design - consequently, there is a need for large randomized controlled studies (Hindle, Petrelli, Clare, & Kalbe, 2013; Leung et al., 2015). Moreover, neural effects of cognitive training are largely unknown in PD. Furthermore, it is important to study the improvement of patients on daily functioning after cognitive training, rather than solely focusing on cognitive tasks and neural measures. Finally, cognitive training has been performed mainly in hospital settings, while PD patients have mobility problems - a training method suitable to perform from home is therefore needed for this population.