An empirical evaluation of short-term memory retention using different high-density EEG based brain connectivity measures

It is very vital to identify the variations in the brain activations and visualize the extent of interaction between brain areas to come up with logical interpretations regarding neuronal dynamics during higher-order cognitive functioning. Most cognitive functions are based on interactions between neuronal assemblies distributed across different cerebral regions. In this paper, we evaluate two traditional methods (Squared Coherence Spectrum (SCS) and Directed Transfer Function (DTF)) and one novel approach based on information theory (Phase Transfer Entropy (PTE)) based on the extent to which they can depict the information flow between distant brain regions during a standard visual short-term memory task. Results revealed that PTE was able to depict the performance and visualize the information flow better compared to the traditional techniques. These results demonstrate the applicability of functional brain connectivity measures in determining and visualizing higher-order cognitive functions. We plan to extend the use of these measures in assessing the neural underpinnings of executive functions as well.