Empowering executive functions in healthy elderly: Cognitive Training and multi-session Non-Invasive Brain Stimulation protocols

State of the art: Cognitive consequences of aging are mainly due to deterioration of prefrontal structures and connections. In addition, functional evidences highlighted that elderly show compensatory neural activity when they are engaged in cognitive tasks. Those changes in activation patterns might be deemed as targets for empowerment interventions. Namely, the re-activation of networks supporting cognitive functions by non-invasive brain stimulation (NIBS) might lead to an improvement of the functional profile. Nonetheless, that potential for cognitive empowerment and prevention is still understudied. Further, the vast majority of studies focusing on the effect of NIBS on cognitive performances in older people usually implement single-session stimulation protocols. The present study aims at investigating the efficacy of an integrated multi-session prefrontal neuromodulation protocol in improving executive control in healthy elderly. Methods: 33 volunteers were randomly divided into a neuromodulation, an active control (cognitive training only), and a wait-list control group and underwent a standardized neuropsychological and electrophysiological (task-related event-related potentials recording) assessment before (t0) and after (t1) the intervention period. The integrated protocol lasted eight weeks and included three sessions per week. Main results: Comparison of t0 and t1 data highlighted improved cognitive profiles for the neuromodulation group. In particular, we observed an increase in Raven’s progressive matrices scores, a potential neuromodulation-induced increase in Stroop test scores, better post-intervention performances at a fluency and conceptual flexibility test (word association fluency test), and an improvement of performances at an attention test (attention matrices). Even performances at a computerized attention task and relative automatic orienting electrophysiological responses were greater in t1 with respect to t0 for the neuromodulation group. Conclusion: We suggest that present findings might mirror the empowerment of executive control exerted by prefrontal areas and – in agreement with participants’ positive reports on their experience – that they may hint at interesting potential implications in terms of intervention opportunities.