Effects of theta burst stimulation over the dorsolateral prefrontal cortex on language switching - A behavioral and ERP study.

ABSTRACT

This study investigated the role of the left dorsolateral prefrontal cortex (DLPFC) in language switching using theta burst stimulation (TBS) and electroencephalography in late bilinguals. After a sham-controlled baseline, participants received either excitatory or inhibitory TBS over the left DLPFC before conducting picture naming tasks in pure language blocks and a language switching block, as well as a nonverbal switching task. On the behavioral level, we found no effect of TBS. However, the ERP-analysis revealed an effect of Stimulation for the picture naming tasks, characterized by alterations in the left DLPFC at 20-72 ms, and in networks associated with conflict resolution and self-monitoring at 533-600 ms. As we did not find an interaction between Stimulation and Block (switching vs non-switching), prefrontal stimulation did not specifically modulate interlanguage control. The left DLPFC might rather be involved in enhancingmaintenance of task demands and self-monitoring during language production in both mono- and bilingual contexts.