AUTHOR=Nikolin Stevan , Lauf Shani , Loo Colleen K. , Martin Donel 

TITLE=Effects of High-Definition Transcranial Direct Current Stimulation (HD-tDCS) of the Intraparietal Sulcus and Dorsolateral Prefrontal Cortex on Working Memory and Divided Attention

JOURNAL=Frontiers in Integrative Neuroscience

VOLUME=12

YEAR=2019

URL=https://www.frontiersin.org/journals/integrative-neuroscience/articles/10.3389/fnint.2018.00064

DOI=10.3389/fnint.2018.00064

ISSN=1662-5145

ABSTRACT=<p><bold>Objective:</bold> There is a need to elucidate the underlying neural mechanisms subserving working memory and divided attention functioning. Recent neuroimaging studies provide evidence for anatomical co-localization of both functions. In the present study we used a functional intervention, whereby we applied a novel type of focalised, non-invasive brain stimulation, High-Definition transcranial Direct Current Stimulation (HD-tDCS), to the regions subserving these processes, the left intraparietal sulcus (IPS) and left dorsolateral prefrontal cortex (LDLPFC). Our aim was therefore to modulate activity in these regions using HD-tDCS and thereby assess their relevance for working memory, divided attention and their shared sub-processes.</p><p><bold>Method:</bold> 78 participants were evenly randomized to one of three conditions in a single blind, parallel group study design. Anodal or sham HD-tDCS was applied to either the left IPS or LDLPFC while participants completed a verbal working memory task, a divided attention task, and two tasks measuring subcomponents of working memory (updating and maintenance).</p><p><bold>Results:</bold> Focalised stimulation of the IPS and LDLPFC did not significantly modulate performance compared to sham stimulation. However, moderate effect sizes were obtained for at least one HD-tDCS condition relative to sham for all tasks, warranting further research into the functional importance of the IPS in subserving these abilities.</p><p><bold>Conclusions:</bold> The current results may be useful for informing future tDCS studies for modulating working memory and divided attention functioning.</p>