Absence of evidence for post-training tDCS effects on motor memory consolidation and premotor–primary motor cortex interaction: a resting-state EEG study

We observed no meaningful post-training tDCS effects on motor consolidation relative to the sham intervention. Likewise, we found no evidence that post-training tDCS altered beta-band functional connectivity or directed information flow between the left M1 and dPMC. Our findings, therefore, do not provide evidence for a meaningful effect of post-training tDCS of M1 on the offline motor memory consolidation process. However, independent of intervention type, significant post-training increases in beta-frequency power were observed across M1 and dPMC subregions. An exploratory follow-up analysis indicated that stronger directional interactions from M1 to the dPMC could be related to enhanced motor consolidation-a hypothesis that should be further investigated in future studies.