Evaluating phase synchronization methods in fMRI: A comparison study and new approaches

In recent years there has been growing interest in measuring time-varying functional connectivity between different brain regions using resting-state magnetic resonance imaging (rs-fMRI) data. One way to assess the relationship signals from is measure their phase synchronization (PS) across time. There are several ways perform such analyses, and we compare methods that utilize a PS metric together with sliding window, referred here as windowed (WPS), those directly instantaneous (IPS). particular, IPS recently gained popularity it offers single time-point resolution of time-resolved fMRI connectivity. this paper, discuss underlying assumptions required for performing analyses emphasize importance band-pass filtering data obtain valid results. Further, contrast approach use Empirical Mode Decomposition (EMD) achieve similar goals. We review various evaluating introduce new within framework denoted cosine relative (CRP). through series simulations application rs-fMRI Our results indicate CRP outperforms other tested overcomes issues related undetected temporal transitions positive negative associations common analysis. coherence, unfolds distribution measures, which benefits subsequent clustering matrices into recurring states.