The REACT trial has been designed as a feasibility study to investigate the impact of pre-, peri-, and postoperative computerized cognitive trainings on the incidence of postoperative cognitive dysfunction. Two different study groups (training programs) will be compared. Each group consists of two training modules of the validated computer based training program of cognitive functioning called RehaCom®. The experimental group consists of the modules 'Topological Memory (MEMO)' and 'Divided Attention 2 (GEA2)'. The active comparator group consists of the modules 'Topological Memory (MEMO)' and 'Working memory (WOME)'. 48 surgical patients undergoing elective urogynecological or breast cancer surgery will preoperatively be randomly assigned to one of two study groups. Before starting the training, patients will complete a neuropsychological test battery comprising the cognitive tests to measure POCD. The tests will be assessed at preoperative baseline visit and at 3-months follow-up. In order to correct change in cognitive performance for practice effects, a group of 24 female surgical control subjects will also prospectively be tested with the cognitive test battery at baseline and 3-months follow-up. The control subjects will be matched to the 2 study groups regarding health status, surgery and age, but will neither undergo the computerized cognitive training program RehaCom®. Further, 24 female control subjects are included from the POCD-Register (EA1/104/16) and will be matched to the 2 study groups as well.