Abstract: PURPOSE: Based on the early research evidence, both the anterior prefrontal cortex (aPFC) and the dorsolateral prefrontal cortex (DLPFC) of the frontopolar cortex play a crucial role in prospective memory (PM) and working memory (WM). However, the specific involvement of both regions in PM and WM is still unclear. The current study aimed to investigate the role of distinct regions in the human prefrontal lobe in PM and WM functioning, and to find out which parts of the prefrontal lobe are particularly involved in supporting them.
METHODS: We used inhibitory continuous theta-burst stimulation (cTBS) to interfere with the functions of the right aPFC or the right DLPFC, and the vertex (serving as a control site). There were four kinds of tasks to carry out, including oddball task (OB), 1-back WM task (1B), 3-back WM task (3B), and dual-task (PM-1B). The performance of 18 healthy volunteers was evaluated on different days after cTBS over three sites.
RESULTS: Compared with the control site (vertex), the application of cTBS over the right aPFC as well as right DLPFC significantly increased the response times (RTs) of 1-back target detection within dual-task, and 1-back task's accuracy was lower after cTBS over the right DLPFC compared with the vertex.
CONCLUSIONS: These findings provide evidence for a key role of the aPFC and the DLPFC in cognitive control, in particular, the role of DLPFC is more prominent.

Key words: prefrontal cortex, prospective memory, working memory, transcranial magnetic stimulation, cognitive control