An evaluation of PDLI values in the rats for the electrode pair FCTX and PCTX using MANOVA revealed a main effect of group (periadolescents vs. adults: F=75.1, df=1,60, p<0.001), and a main effect of tone (frequent vs. infrequent: F=65.4, df=1,60, p<0.001). The infrequent tone had a significantly higher grand mean PDLI value (0.71 ± 0.01) than the frequent tone (0.58 ± 0.01). Grand means also revealed that periadolescents had significantly lower PDLI values (0.57) than adults (0.71). ANOVA identified that for the frequently presented tone that periadolescents had significantly lower PDLI than adults for all time frequency regions of interest except delta (F values range= 18.8-52.4). The phase difference lock index (PDLI) for the electrode pair FCTX and PCTX, for the infrequent tone in adult and periadolescent rats is shown in Figure 6b and Table 5. Repeated measures ANOVA revealed that periadolescent rats had significantly lower PDLI levels than adults to the infrequent tone in the theta (F=28.9, df=1,31, p<0.001), alpha (F=45.3, df=1,31, p<0.001) and beta (F=11.1, df=1,31, p=0.002) frequency ranges.
