EEG functional network on oddball paradigm: connectivity estimation based on ERP waveforms

Abstract

In this study, we analyzed functional connectivity directly from event related potential (ERP) waveforms elicited during the oddball task. We empirically estimated non-rhythmic phases of the temporal unfolding of ERP waveforms, calculated the phase locking index (PLI), and quantified the resulting network topology by extracting minimum spanning tree (MST). Overall PLI is higher in the target condition. Specifically, PLI between right parietal and other areas are significantly higher (paired t-test, p<0.05) than those in nontarget condition. According to MST metrics,target ERPs revealed higher degree, higher leaf fraction, lower kappa and larger mean weight (paired t-test, p <0.05).The results showed that target ERPs resulted in higher connectivity.