Combining transcranial electrical stimulation with training in older adults: Effects on dual-task ability

Background: Enhancing dual-task (DT) performance in older adults through cognitive improvement may help prevent neurodegenerative decline.Objective: This study aimed to investigate the efficacy of combining repeated transcranial electrical stimulation (tES) targeting the left dorsolateral prefrontal cortex (L-DLPFC) with task training on DT ability in healthy older adults.Methods: Fifty-eight participants were randomized to receive ten 20-min sessions of cognitive and motor task training concurrently applied with either anodal transcranial direct current stimulation (tDCS), 4 Hz transcranial alternating current stimulation (tACS), or sham tES.Results: All groups demonstrated significant cognitive improvements under both single-and DT conditions immediately and four weeks after the intervention, with no between-group differences.Although motor dual-task costs decreased across all groups, this did not translate into measurable performance gains.Conclusion: Overall, tES did not provide significant additive effects on DT performance when combined with multi-session training interventions.