Longitudinal neurostimulation in older adults improves working memory.

Area of Science:

• Neuroscience
• Cognitive Psychology
• Gerontology

Background:

• Working memory (WM) decline is a growing concern in the aging population.
• Current brain training exercises offer limited long-term benefits and minimal transfer to untrained tasks.
• Neurostimulation paired with training may enhance plasticity and improve WM performance.

Purpose of the Study:

• To investigate if transcranial direct current stimulation (tDCS) combined with working memory (WM) training can provide sustained cognitive benefits in healthy older adults.
• To assess the long-term effects of tDCS-enhanced WM training on both trained and untrained cognitive tasks.

Main Methods:

• Healthy older adults received 10 sessions of sham or active (anodal, 1.5 mA) tDCS targeting right prefrontal and/or parietal cortices.
• Participants underwent verbal and visual WM training tasks after each tDCS session.
• Cognitive performance was assessed on trained tasks and transfer tasks (spatial 2-back, Stroop, digit span) during sessions and at a 1-month follow-up.

Main Results:

• All participants showed improvements from WM training.
• Only active tDCS groups maintained significant WM improvements at the 1-month follow-up.
• Sustained benefits were observed for both trained and untrained tasks in the active tDCS groups.

Conclusions:

• tDCS-linked WM training can enhance and prolong the cognitive benefits of brain training in older adults.
• This combined approach effectively transfers improvements to untrained cognitive tasks, suggesting enhanced neural plasticity.
• tDCS represents a promising strategy for long-term WM enhancement in aging populations.