  Working Memory (WM) load is an important cognitive feature that is highly
correlated with mental effort. Several neurological biomarkers such as theta
power and mid-frontal activity show increased activity with increasing WM load.
Such correlations often break down in cognitively impaired individuals, making
WM load biomarkers a valuable tool for the detection of cognitive impairment.
However, most studies have used a multi-channel EEG or an fMRI, which are not
massively accessible. In the present study, we evaluate the ability of novel
features extracted from a single-channel EEG located on the forehead, to serve
as markers of WM load. We employed the widely used n-back task to manipulate WM
load. Fourteen participants performed the n-back task while their brain
activity was recorded with the Neurosteer inc Aurora EEG device. The results
showed that the activity of the newly introduced features increased with WM
load, similar to the theta band, but exhibited higher sensitivity to finer WM
load changes. These more sensitive biomarkers of WM load are a promising tool
for mass screening of mild cognitive impairment.
