  Many studies have shown that the dorsolateral prefrontal cortex (DLPFC) plays
an important role in top-down cognitive control over intentional and deliberate
behavior. However, recent studies have reported that DLPFC-mediated top-down
control interferes with implicit forms of learning. Here we used continuous
theta burst stimulation (cTBS) combined with electroencephalography (EEG) to
investigate the causal role of DLPFC in implicit contextual memory-guided
attention. We aimed to test whether transient disruption of the DLPFC would
interfere with implicit learning performance and related electrical brain
activity. We applied neuronavigation-guided cTBS to the DLPFC or to the vertex
as a control region prior to the performance of an implicit contextual learning
task. We found that cTBS applied over the DLPFC significantly improved
performance during implicit contextual learning. We also noted that beta-band
(13-19 Hz) oscillatory power was reduced at fronto-central channels about 140
to 370 ms after visual stimulus onset in cTBS DLPFC compared with cTBS vertex.
Taken together, our results provide evidence that DLPFC-mediated top-down
control interferes with contextual memory-guided attention and beta-band
oscillatory activity.
