Figure 1(b) shows the grand average log-transformed EROEVK TFR at electrode site Cz for the NACs. The power in the ERP is localized to the first 700 ms post stimulus, with peak power occurring from 200 to 500 ms and between 4 to 5 Hz. The EROTOT TFR at electrode site Cz showed a similar distribution in the delta and theta band, but with the peak value of the theta power being approximately 3 times larger (on a linear scale) in the EROTOT TFR compared to the EROEVK TFR. The main difference between TFRs was in the alpha band, where the EROTOT TFR showed significantly larger pre-stimulus alpha power than in the EROEVK TFR. The alpha power showed desynchronization (i.e. showed a decrease in power), after stimulus onset, at approximately 200ms post-stimulus, with maximum desycnronization at around 600ms post-stimulus. The alpha power returned to pre-stimulus baseline levels by approximately 1000ms post-stimulus.
