The second major research question also concerned whether adults differed from periadolescents in ERO responses to auditory stimuli in rats. An evaluation of energy values in the rats using MANOVA revealed a main effect of group (periadolescents vs. adults: F=152.1, df=1,124, p<0.001), and a main effect of tone (frequent vs. infrequent: F=8.7, df=1,124, p=0.004) and a main effect of electrode location (F=12.4, df=1,124, p=0.001). The infrequent tone had a significantly higher overall energy (546.5 ±27.4) than the frequent tone (431.9 ±27.4). Grand means revealed that periadolescents had significantly higher energy (728.1 ± 29.0) than adults (250.2 ± 25.7). ANOVA identified that for the frequently presented tone that periadolescents had significantly higher energy than adults in all electrode locations for all time frequency ROIs (F values range= 10.2-57.1).
