Regarding the stimulation frequencies, the moderator analysis with absolute effect sizes supported the notion that high-frequency TMS would significantly influence RT ( g = 0.21, 95% CI: 0.03–0.38, p = 0.019), while low-frequency TMS showed a trend toward significantly affecting ACC ( g = 0.16, 95% CI: −0.01–0.34, p = 0.067).
There was a significant difference between the traditional random effects model and the three-level random effects model in ACC (LRT = 9.99, p = 0.007), and a trend toward significance in RT (LRT = 2.80, p = 0.09).
Further moderator analyses indicated that (a) for language tasks , TMS induced significant neuromodulatory effects on semantic and phonological tasks, but didn’t show significance for syntactic tasks; (b) for cortical targets , TMS effects were not significant in left frontal, temporal or parietal regions, but were marginally significant in the inferior frontal gyrus in a finer-scale analysis; (c) for stimulation parameters , stimulation sites extracted from previous studies, rTMS, and intensities calibrated to the individual resting motor threshold are more prone to induce robust TMS effects.