Investigating Hemispheric Specialization of the Dorsolateral Prefrontal Cortex in Visuospatial Working Memory

The dorsolateral prefrontal cortex (DLPFC) plays an important role in visuospatial working memory (VSWM). However, its hemispheric specialization in this cognitive process remains unclear. Here, we aimed to establish whether the DLPFC is hemispherically specialized in the VSWM. Therefore, we applied cTBS over either left or right DLPFC, with vertex as a control site. We recruited 36 participants for the experiment, 18 each for the left and the right DLPFC group. Each participant received a 40 s cTBS over the left or the right DLPFC depending on the group. The stimulation was applied at a uniform intensity of 40% of the maximal stimulator output (MSO) of the Magstim super rapid magnetic stimulator for all subjects. Our results indicated an impairment of VSWM task performance after the cTBS over the right DLPFC relative to the vertex stimulation. While cTBS over the left DLPFC did not significantly decrease the performance. Taken together, our results suggest that the right DLPFC is prominently involved in the VSWM and that cTBS can be used to effectively perturb the activity of the focal brain areas.