Figure 4a gives the mean (± SE) values for the PLI for each frequency range for the three electrode locations for the periadolescents and adults, for the infrequent (target) tone in the human participants. Repeated measures ANOVA revealed that adults had significantly higher PLI levels than periadolescents to the infrequent (target) tone in the delta (F=6.7, df=1,56, p= 0.01) and theta (F=8.4, df=1,56, p=0.005) frequencies in frontal cortex (FZ) and in the delta (F=18.9, df=1,56, p=0.001), and theta (F=8.1, df=1,56, p<0.006) frequency ranges in central cortex (CZ) as seen in Table 4. Significant increases in PLI were also seen in the adults as compared to the periadolescents at parietal sites (PZ) in the delta (F=22.2, df=1,56, p<0.001) and theta (F=9.2, df=1,56, p<0.004) frequency ranges for the infrequent (target) tone. Grand averages of PLI values for the infrequent (target) tone for periadolescents and adults in the active task are seen in Figure 5.
