Figure 6. A linear regression analysis for median power frequency. The apparent linear relation that occurs between the median power frequency and the cerebral metabolic reduction evident at the various levels of anesthesia is not statistically significant. The lines joining each volunteer's data points suggest that increasing levels of anesthesia are, nonetheless, associated with lower median power frequency values coincident with greater reductions in cerebral metabolism for each volunteer. The lines and labels are as shown in Figure 2.