Modulating the interference effect on spatial working memory by applying transcranial direct current stimulation over the right dorsolateral prefrontal cortex
Journal
Brain and Cognition
Series/Report No.
Brain and Cognition
Journal Volume
91
Start Page
87-94
ISSN
0278-2626
Date Issued
2014-11-01
Author(s)
DOI
10.1016/j.bandc.2014.09.002
Abstract
Spatial working memory (SWM) is the ability to temporarily store and manipulate spatial information. It has a limited capacity and is quite vulnerable to interference. Dorsolateral prefrontal cortex (DLPFC) has been shown to be a part of the SWM network but its specific functional role still remains unknown. Here we applied transcranial direct current stimulation (tDCS), a noninvasive brain stimulation technique that provides polarity-specific stimulation over the targeted region, to investigate the specific role of the right DLPFC in resolving interference in SWM. A forward- and backward-recall computerized Corsi Block Tapping task (CBT), both with and without a concurrent motor interference task (the modified Luria manual sequencing task) was used to measure SWM capacity and reaction time. The results showed that motor interference impeded accuracy and prolonged reaction time in forward and backward recall for SWM. Anodal tDCS over right DLPFC yielded the tendency to shorten participants' reaction time in the conditions with interference (forward with interference, and backward with interference). Most importantly, anodal tDCS significantly improved participants' SWM span when cognitive demand was the highest (the "backward-recall with motor interference" condition). These results suggest that (1) the right DLPFC plays a crucial role in dealing with the cross-domain motor interference for spatial working memory and (2) the anodal tDCS over right DLPFC improved SWM capacity particularly when task difficulty demands more complex mental manipulations that could be due to the facilitatory effect of anodal tDCS which enhanced the DLPFC function within central executive system at the top-down attentional level.
Subjects
Corsi block tapping task
Dorsolateral prefrontal cortex
Interference effect
Spatial working memory
Top-down control
Transcranial direct current stimulation
Visual short-term memory
Visual working memory
Visuospatial working memory
Publisher
Elsevier BV
Type
journal article