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Reliability of event-related EEG functional connectivity during visual entrainment: Magnitude squared coherence and phase synchrony estimates


  • This research was supported by grants from the National Institute of Mental Health (R01 MH084932-02 and R01 MH097320) and from the U.S. Army Medical Research Acquisition Activity (USAMRAA) (W81XWH-11-2-0008) awarded to AK and by a fellowship from the Canadian Institutes of Health Research (CIHR) awarded to VM.


There is an increasing trend towards using noninvasive electroencephalography (EEG) to quantify functional brain connectivity. However, little is known about the psychometrics of commonly used functional connectivity indices. We examined the internal consistency of two different connectivity metrics: magnitude squared coherence and phase synchrony. EEG was recorded during visual entrainment to elicit a strong oscillatory component of known frequency. We found acceptable to good split-half reliability for the connectivity metrics when computing all possible pairwise interactions and after selecting an a priori seed reference. We also compared reliability estimates when using average referenced sensor versus reference independent current source density EEG data. Additional considerations were given to determining how reliability was influenced by factors including trial number, signal-to-noise ratio, and frequency content.