Does excitatory fronto-extracerebral tDCS lead to improved working memory performance?

Area of Science:

• Neuroscience
• Cognitive Psychology

Background:

• Excitatory transcranial direct current stimulation (tDCS) shows promise for cognitive enhancement.
• Its application in neuropsychiatric disorders with cognitive deficits is of interest.
• Optimal stimulation parameters for tDCS remain under investigation.

Purpose of the Study:

• To investigate the efficacy of 1 mA anodal left dorsolateral prefrontal cortex (dlPFC) tDCS on working memory performance.
• To assess working memory enhancement over two consecutive days compared to sham stimulation.

Main Methods:

• A double-blind, between-subjects design was employed.
• Participants underwent 1 mA anodal dlPFC tDCS or sham stimulation.
• Working memory was assessed using the 3-back task at baseline, during, and after stimulation over two days.

Main Results:

• Overall, active tDCS did not yield significant improvements in working memory compared to sham stimulation.
• Exploratory analysis revealed a significant performance enhancement in the active stimulation group during the initial stimulation phase only.
• This suggests a potential transient effect of dlPFC tDCS on working memory.

Conclusions:

• The study does not support the hypothesis that dlPFC tDCS consistently enhances working memory.
• Findings suggest that the cognitive effects of tDCS might be more pronounced during the early stages of task learning or acquisition.