Transcranial magnetic stimulation to left VLPFC or right DLPFC promotes forgetting in working memory

Abstract Background Individuals can intentionally process task-relevant information while ignoring task-irrelevant information. This study aims to investigate how to promote forgetting of task-irrelevant information through noninvasive brain stimulation, utilizing direct suppression and thought substitute inhibition mechanisms. Methods Participants were cued to either remember task-relevant information while forgetting task-irrelevant information (IR condition) or to forget task-irrelevant items while remembering task-relevant information (IF condition). High-frequency rTMS was applied to activate the left ventrolateral prefrontal cortex (VLPFC, n = 32), right dorsolateral prefrontal cortex (DLPFC, n = 32), or vertex cortex (control condition, n = 32). Results Compared to vertex stimulation, (1) The Left VLPFC stimulation promoted the memory of task-relevant information in the IR condition, and resulted in a memory deficit for the task-irrelevant information in the IF condition (active forgetting). (2) The Right DLPFC stimulation promoted the forgetting of task-irrelevant information in the IF condition (active forgetting) and facilitated the memory of task-relevant information in the IR condition. Conclusions Stimulating left VLPFC or right DLPFC can promote active forgetting. Noninvasive brain stimulation can effectively regulate memory control.