Diedrich Lukas, Kolhoff Hannah I, Bergmann Clara, Bähr Mathias, Antal Andrea
Department of Neurology, University Medical Center Göttingen, Göttingen, Germany.
Geroscience. 2025 Apr;47(2):1425-1440. doi: 10.1007/s11357-024-01272-3. Epub 2024 Jul 12.
The escalating global burden of age-related neurodegenerative diseases and associated healthcare costs necessitates innovative interventions to stabilize or enhance cognitive functions. Deficits in working memory (WM) are linked to alterations in prefrontal theta-gamma cross-frequency coupling. Low-intensity transcranial alternating current stimulation (tACS) has emerged as a non-invasive, low-cost approach capable of modulating ongoing oscillations in targeted brain areas through entrainment. This study investigates the impact of multi-session peak-coupled theta-gamma cross-frequency tACS administered to the dorsolateral prefrontal cortex (DLPFC) on WM performance in older adults. In a randomized, sham-controlled, triple-blinded design, 77 participants underwent 16 stimulation sessions over six weeks while performing n-back tasks. Signal detection measures revealed increased 2-back sensitivity and robust modulations of response bias, indicating improved WM and decision-making adaptations, respectively. No effects were observed in the 1-back condition, emphasizing dependencies on cognitive load. Repeated tACS reinforces behavioral changes, indicated by increasing effect sizes. This study supports prior research correlating prefrontal theta-gamma coupling with WM processes and provides unique insights into the neurocognitive benefits of repeated tACS intervention. The well-tolerated and highly effective multi-session tACS intervention among the elderly underscores its therapeutic potential in vulnerable populations.
与年龄相关的神经退行性疾病全球负担不断加重，相关医疗保健成本不断攀升，因此需要采取创新干预措施来稳定或增强认知功能。工作记忆（WM）缺陷与前额叶θ-γ跨频耦合改变有关。低强度经颅交流电刺激（tACS）已成为一种非侵入性、低成本的方法，能够通过同步作用调节目标脑区的持续振荡。本研究调查了对背外侧前额叶皮质（DLPFC）进行多疗程峰值耦合θ-γ跨频tACS对老年人WM表现的影响。在一项随机、假刺激对照、三盲设计中，77名参与者在进行n-back任务的同时，在六周内接受了16次刺激疗程。信号检测测量显示，2-back任务的敏感性增加，反应偏差得到有力调节，分别表明WM改善和决策适应性提高。在1-back任务条件下未观察到效果，强调了对认知负荷的依赖性。重复tACS强化了行为变化，效应大小增加表明了这一点。本研究支持了先前将前额叶θ-γ耦合与WM过程相关联的研究，并为重复tACS干预的神经认知益处提供了独特见解。老年人对多疗程tACS干预耐受性良好且效果显著，凸显了其在弱势群体中的治疗潜力。
