Disruption of the prefrontal cortex improves implicit contextual memory-guided attention: combined behavioural and electrophysiological evidence

TL;DR

Disruption of the dorsolateral prefrontal cortex via cTBS enhances implicit contextual memory-guided attention and reduces beta oscillations, indicating DLPFC's inhibitory role in implicit learning processes.

Contribution

This study provides causal evidence that transient DLPFC disruption improves implicit learning and alters associated neural oscillations, challenging previous notions of its solely top-down control.

Findings

cTBS over DLPFC improves implicit learning performance

DLPFC disruption reduces beta-band oscillatory power

DLPFC interference hampers implicit contextual memory-guided attention

Abstract

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.