TFRs were computed from the trials having the correct behavioral responses for each of the stimuli types (target, rare non-target and standard non-target). TFRs were computed using two different methods, namely the Stockwell Transform (ST) and the Short-time Fourier Transform (STFT). The ST methodology is the same as utilized in Jones et al. (2006), Rangaswamy et al. (2007) and Andrew and Fein (In Press), and the reader is referred to these papers for a detailed account of this methodology. STFT methodology has been widely applied to event-related EEG data (Makeig, 1993; Pfurtscheller and Andrew, 1999). For the STFT method, a window length comprising 128 data points (corresponding to 512 ms), a zero-padding factor of 4 and pre-windowing of the data with a Hanning window were utilized for estimation of the power spectrum at each time point in the TFR.
