Improved cognitive promotion through accelerated magnetic stimulation.

Abstract Objective: Noninvasive brain stimulation to enhance cognition is an area of increasing research interest. Theta burst stimulation (TBS) is a novel accelerated form of stimulation, which more closely mimics the brain’s natural firing patterns and may have greater effects on cognitive performance. We report here the comparative assessment of the effect of conventional high-frequency repetitive transcranial magnetic stimulation (HF-rTMS) protocols and TBS protocols on cognition enhancement in healthy controls. Methods: Sixty healthy adults (34 males and 26 females) were randomized and counterbalanced and assigned to HF-rTMS (n=20), TBS (n=20), or sham (n=20) groups. The promotion effects of different parameters of prefrontal stimulation on working memory and executive function were compared, as assessed by performance in N-back tasks and the Wisconsin Card Sorting Test (WCST). Results: Both HF-rTMS and intermittent TBS (iTBS) groups displayed a significant improvement in N-back tasks, with an effect size of 0.79 and 1.50, respectively. Furthermore, the iTBS group displayed a significant improvement in the WCST, with an effect size of 0.84. The iTBS group demonstrated higher effect sizes than the HF-rTMS group (t=2.68, P=0.011), with an effect size of 0.85. However, no improvement in other tasks was observed (P>0.05). Conclusions: Intermittent TBS has a stronger cognitive promoting effect than conventional rTMS. In summary, our findings provide direct evidence that iTBS may be a superior protocol for cognitive promotion. Significance Statement •This study presents a randomized, placebo-controlled, parallel, double-blinded comparison of the effects of 20 Hz rTMS and iTBS applied over the left dorsolateral prefrontal cortex, on working memory and executive functions. •Significant improvements in working memory performance were observed following active 20 Hz rTMS and iTBS, the effect size of which were 0.71 and 1.50, respectively. •The improvement of executive function (cognitive flexibility) performance was observed following iTBS, but not in 20 Hz rTMS. •This study demonstrated that iTBS has a stronger cognitive promoting effect than 20 Hz rTMS and provided direct evidence that iTBS may be a better protocol for cognitive promotion.