Working memory (WM) is one of the most investigated cognitive functions albeit the extent to which individual characteristics impact on performance is still unclear, especially when older adults are involved. The present study considers repeated practice of a visual N -Back task with three difficulty levels (1-, 2-, and 3-Back) in healthy young and older individuals. Our results reveal that, for both age groups, the expected mental fatigue was countered by a learning effect, in terms of accuracies and reaction times, which turned out to benefit females more than males, for all three N -Back levels. We conclude that future WM studies, in particular when relying on repeated N -Back sessions, should account for learning effects in relation to mental fatigue and gender, in both young and older adults.

Little is known about the effect of strategy use on working memory training in aging. Here, we aim to assess the impact of strategy on trained and transfer tasks for accuracy and P300, while investigating the effect of age, gender and education. We recruited 26 elderly and recorded EEGs from the cognitive training group and active control group. Our results showed changes in P300, but only a positive trend in accuracy for the trained task across groups. We found transfers to untrained tasks, but we did not observe any difference in transfer effects between training groups. However, our results showed significant differences between training groups for a similar version of the trained task, suggesting that strategy use might have prolonged effects. Individual characteristics had a significant impact on accuracy and P300 for trained and transfer tasks. These findings underline the role of strategy use and individual characteristics during N-Back training.

Although recent studies showed the beneficial effect of video game training, it is still unclear whether the used strategy plays an important role in enhancing performance in the trained cognitive ability and in promoting transfers to other cognitive domains. We investigated behaviourally the effect of strategy on the outcomes of visual attentional control game training and both behaviourally and in terms of EEG-based event-related potentials (ERPs), the effect on other cognitive domains. We recruited 21 healthy young adults (M = 24.33, SD = 3.23), and randomly divided them into three groups: a strategy-training group (STG) instructed to use a specific strategy, a non-strategy training group (NSTG) that self-developed their strategy, and a passive control group (PCG) that underwent only pre-and post-tests (Oxford Cognitive Screen test, Buschke Selective Reminding Test, D2 test of Attention, Digit span test, BADS test, Bells test, Oddball and N-Back tests). Our results showed that the use of a specific strategy made the STG participants respond faster to the trained contrast level task, but not on the contour exercises task. Furthermore, both STG and NSTG showed pre-and post-transfers, however no significant differences were found when comparing the groups, for both behaviour and ERP responses. In conclusion, we believe these preliminary results provide evidence for the importance of strategy choice in cognitive training protocols.