Investigating the influence of paired-associative stimulation on multi-session skill acquisition and retention in older adults.

Abstract Objective Priming non-invasive brain stimulation (NIBS) can improve motor learning in the elderly, but it remains unclear how benefits observed in a single training session translate to multiple training sessions. The current study therefore examined the influence of priming NIBS on acquisition and retention of a novel motor skill over sequential training days in older adults. Methods In 30 older adults (68.2 ± 5.3 years, 14 females), paired-associative stimulation (PAS) was applied prior to visuomotor training on 3 consecutive days. The interstimulus interval used for PAS was either 10 ms (PASLTD) or 100 ms (PASControl) and long-term retention was assessed by quantifying motor performance 7 days after the final training session. Results During training, skill progressively increased across sessions (P   0.1). In contrast, the magnitude of skill retained 7 days after training was significantly greater in the PASLTD group (P = 0.02), suggesting significantly greater long-term retention of the trained skill. Conclusions PASLTD over multiple sessions may represent an effective tool to help maintain newly learned motor skills in older adults. Significance While multisession priming with PAS can influence long-term skill retention, improving skill acquisition requires investigation of alternative protocols.