Continuous theta-burst stimulation over the right dorsolateral prefrontal cortex impairs visuospatial working memory...

Area of Science:

• Neuroscience
• Cognitive Psychology

Background:

• Visuospatial working memory (VSWM) is vital for processing visual information.
• Frontal and parietal areas are implicated in VSWM, with the frontal cortex regulating goal-directed behavior.
• The specific role of the right dorsolateral prefrontal cortex (rDLPFC) in VSWM remains unclear.

Purpose of the Study:

• To investigate the causal role of the rDLPFC in VSWM.
• To examine the effects of noninvasive brain stimulation on VSWM performance.
• To determine if rDLPFC modulation impacts performance differently based on working memory load.

Main Methods:

• Continuous theta-burst stimulation (cTBS) was used to noninvasively modulate rDLPFC activity.
• The vertex served as a control stimulation site.
• Working memory performance on 2-back and 4-back tasks was assessed before and after stimulation.

Main Results:

• rDLPFC modulation with cTBS significantly impaired performance on the 2-back task (lower load).
• Performance on the 4-back task (higher load) was not significantly affected by rDLPFC modulation.
• No significant changes in performance were observed after cTBS over the vertex control site.

Conclusions:

• The findings support a functional role for the rDLPFC in VSWM.
• Working memory performance is load-dependent, with rDLPFC involvement more apparent at lower loads.
• Noninvasive brain stimulation is an effective tool for probing the neural underpinnings of cognitive functions like VSWM.