evoked delta and alpha/beta phase locking. Our findings also showed that ERO energy in the parietal theta and alpha/beta bands was lower in NP than in P rats. However, these differences were only observed in response to the standard tones, whereas reductions in P3 amplitudes in P rats were found in response to the noise tones. The results suggesting that baseline ERO energy in the parietal alpha/beta bands was higher in P than in NP rats are consistent with our previous studies characterizing EEG power in P and NP rats (Ehlers et al., 1999). These differences in baseline ERO energy in the alpha/beta bands were observed in response to standard, rare and noise tones and are likely independent to the reductions in P3 amplitude in P rats in response to noise tones (Ehlers et al., 1999).
