Estimates of localized power of non-stationary evoked potential time series were obtained using the S-transform, a time-frequency representation method developed by Stockwell (Stockwell et al., 1996). This method has been previously described and implemented in our laboratory to evaluate event-related signals in the time-frequency domain (Jones et al., 2006a,b; Kamarajan et al., 2006; Rangaswamy et al., 2007).
