Enhancing working memory in MCI: Modulating alpha-gamma coupling and gamma oscillations via rTMS

Cross-frequency coupling (CFC), particularly the interaction between alpha and gamma oscillations, is a pivotal mechanism implicated in cognitive function, with potential for modulation by repetitive transcranial magnetic stimulation (rTMS). This study aimed to investigate the impact of high-frequency rTMS (HF rTMS) on CFC and visual working memory (VWM) in individuals with mild cognitive impairment (MCI). Twenty MCI patients and twenty healthy controls were administered 10Hz rTMS targeting the left dorsolateral prefrontal cortex (DLPFC). Our critical findings indicate that post-intervention, MCI patients exhibited significant enhancements in VWM performance, notably under low memory load. These improvements correlated with a reduction in occipital gamma activity, and were concurrent with strengthened phase-amplitude coupling (PAC) between frontal alpha and occipital gamma oscillations. The results underscore the capacity of alpha-band HF rTMS to modulate neural activity, offering a promising, non-invasive strategy for enhancing cognitive performance in MCI.