Two-way repeated measures ANOVA with ERO energy as dependent variable revealed a significant main effect of Tone in the delta (0–50 ms and 350–800 ms time windows), theta (0–50 ms time window) and alpha/beta (0–50 ms, 50–350 ms and 350–800 ms time windows) frequency bands in the frontal cortex (Table 1). Repeated measures ANOVA also showed a significant main effect of Tone in the delta (50–350 ms and 350–800 ms time windows), theta (50–350 ms and 350–800 ms time windows) and alpha/beta (0–50 ms and 350–800 ms time windows) bands in the parietal cortex (Table 1). Post hoc pairwise comparisons showed lower ERO mean energy in the frontal and parietal cortices in the delta and theta frequency bands in response to noise tones (vs. standard and/or rare tones) during the 0–50 ms, 50–350 ms and 350–800 ms time windows (Table 1). Lower ERO energy in the parietal delta and theta bands (50–350 ms and 350–800 ms time window) was observed in response to rare tones, compared to standard tones (Table 1). Pairwise analyses indicated lower ERO mean energy in the
