A phase I/II/III clinical trial is proposed in which the first two phases will serve to evaluate the safety of the intervention and the maximum tolerated time of computerized cognitive training per session in the absence of adverse effects. The third phase will consist of a double-blind randomized controlled trial where the effectiveness of the personalized and self-administered computerized cognitive stimulation program will be evaluated.
Phase I. Based on a dose-escalation 3+3 design, experienced fatigue or adverse effects will be measured after succeeding 15 minutes cognitive stimulation training blocks. The training dose will be set to a block before extreme fatigue or notable adverse effect has been reported by two or more participants. A trained psychologist will supervise the process.
Phase II. To evaluate the effectiveness of the intervention, 20 participants will undertake an interspersed training day and evaluation day through 15 consecutive days. In this way, a total of 8 evaluation sessions (day 1, 3, 5, 7, 9, 11, 13, and 15) and 7 cognitive stimulation sessions (day 2, 4, 6, 8, 10, 12, and 14) will be carried out. A trained psychologist will supervise every step of the process.
Phase III. An 8-week personalized and computerized cognitive stimulation program will be established, where the training time per session will be as determined on phase I. 120 participants will be randomized 1:1 ratio to an intervention or active control group. All participants will undertake a pre and post-test, with a total of 40 training sessions (Monday to Friday) during 8 weeks. Although this phase is set to be an online home-based stage, the responsible psychologist will be monitoring participants' performance and will periodically contact participants via telephone.
