Comparison of Brain Functional Networks for Subjects with Different Performance

In this study, brain functional networks are compared for different subjects while performing the visual oddball task. The time series electroencephalography (EEG) signals were acquired from 20 healthy subjects during a visual oddball experiment using 128 channels machine with a sampling rate of 250 Hz. The clean data was filtered by finite impulse response (FIR) filter for EEG rhythmic decomposition. Phase Locked Value (PLV) is used to measure all pairwise phase synchronizations of EEG electrodes. Hilbert transform was then applied to the decomposed data to extract instantaneous phases. Graph theory approach is finally used to quantify the functional networks. Results show that target stimuli elicited denser neural activity as compared to non-target stimuli. Subject with higher performance accuracy when performing the oddball task has greater neural activity than the subject with lower accuracy.