Time-frequency coherence analysis of multi-channel eventrelated potential using adaptive windowed Lomb periodogram

This paper introduces a new time-frequency coherence analysis method based on Lomb periodogram and applies it to investigate the time-varying synchronization of multi-channel event-related potentials (ERP). The Lomb periodogram is first extended to a time-frequency analysis method by windowing the observation. Furthermore, the window bandwidth is selected adaptively by the intersection of confidence intervals (ICI) rule to improve the time-frequency resolution. By using an adaptive window for each sinusoid and at each time instant, the adaptive windowed Lomb periodogram (AWLP) can achieve better bias and variance tradeoff and optimize the time-frequency resolution. Experimental results show that the AWLP-based coherence can provide useful information indicating the direction of information flow and correlation between different cortical regions.