Investigating the effective brain networks related to working memory using a modified directed transfer function

We utilized a combination of orthogonal least squares (OLS) algorithm and short-time direct directed transfer function (SdDTF) for evaluating the effective brain networks. Directional changes in connectivity among brain regions were assessed during two states, resting and working memory (WM). Our results demonstrated an increase in the strength of connectivity between frontal and parietal regions and a decrease in the strength of connectivity between the regions of the default mode network, during task engagement. Connectivity was prominent in the low frequency bands, theta and alpha. Furthermore, during the WM task, theta oscillations increased in the frontal lobe while a reduction was observed in the alpha band.