Influence of Transcranial Magnetic Stimulation on Working Memory Performance in Healthy Young People

Non-invasive brain stimulation (NIBS) is increasingly being used in the dorsolateral prefrontal cortex (DLPFC) to improve working memory (WM) performance. At the same time, NIBS protocols have demonstrated either small or inconclusive cognitive effects in healthy subjects. NIBS uses intermittent theta burst stimulation (iTBS), a modified form of rhythmic TMS (rTMS) that can increase cortical excitability beyond the stimulation period. The purpose of this work is to study the effectiveness of WM tests in healthy young adults against the background of activational neuroplasticity caused by iTBS of the left DLPFC. A double-blind, randomized, placebo-controlled study was conducted in 14 healthy women aged 18–20 years. WM performance was assessed using n-back tests (2-back, 3-back) before and after iTBS of the left DLPFC. Against the background of activational neuroplasticity caused by iTBS of the left DLPFC, there was an increase in the efficiency of solving simple (2-back tests) and a decrease in the accuracy of solving more complex (3-back tests) working memory tasks in healthy young people. It is possible that the observed behavioral differences during active iTBS of the left DLPFC may be associated with a performance ceiling effect in healthy people.