Evaluating the Effect of Applying Cathodal tDCS to the Left Dorsolateral Prefrontal Cortex on Visual Working Memory

Abstract

Objective: Contemporary research has studied non-invasive brain stimulation modalities regarding their impact on various cognitive functions, particularly in the areas of learning and memory. Studies are being pursued to delve into the manipulation of these cognitive facets through this methodology. The aim of the current study was to examine the effects of application of cathodal transcranial direct current stimulation (tDCS) to the left dorsolateral prefrontal cortex (DLPFC), on visual working memory. Materials and Methods: The study consisted of two separate groups, an active and a sham group, in which a total of 42 university students participated. Two mA cathodal direct current was applied to the left dorsolateral prefrontal cortex. To measure visual working memory, the study applied a visual 1-back task consisting of Chinese letters before and after tDCS and compared the obtained data. Results: The study observed significant differences between the active and sham groups, with the active group having an increased number of omissions, a decreased number of correct responses, and prolonged response times. Conclusion: The findings of the study revealed the suppressive effect of cathodal tDCS on visual working memory. Studies in the literature revealed various results regarding the contributions of left and right DLPFC on working memory. The findings of this study showed that right DLPFC also has an effect on visual working memory.

Keywords

• Working memory
• tDCS
• n-back task

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