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Mapping Adolescent Brain Change 65Figure 3-4 Gray matter density age-effect statistical maps (left, right, and top views) showinggray matter density changes between childhood and adolescence (A) and between adolescenceand adulthood (B). Anatomically, the central sulcus (CS), Sylvian fissure (SF),and interhemispheric fissure (IF) are highlighted. In both images, shades of green to yellowrepresent negative Pearson’s correlation coefficients (gray matter loss with increasingage) and shades of blue, purple, and pink represent positive Pearson’s correlationcoefficients (gray matter gain with age) according to the color bar on the right (range ofPearson correlation coefficients from –1 to +1). Regions shown in red correspond to correlationcoefficients that have significant negative age effects at a threshold of p = 0.05(gray matter loss), and regions shown in white correspond to significant positive age effectsat a threshold of p = 0.05 (gray matter density gain). The images on the bottom(C) display a statistical map of the Fisher’s Z transformation of the difference betweenPearson correlation coefficients for the child-to-adolescent and the adolescent-to-adultcontrasts (see color bar on far right representing Z-scores from –5 to +5). Shades of greento yellow represent regions where the age effects are more significant in the adolescentto-adultcontrast (middle) than in the child-to-adolescent contrast (left). Highlighted in redare the regions where the difference between Pearson correlation coefficients is statisticallysignificant (p = 0.05). Shades of blue, purple, and pink represent regions where theage effects are more significant in the child-to-adolescent contrast than the adolescent-toadultcontrast. Highlighted in white are regions where these effects are significant at athreshold of p = 0.05. See color insert. (Sowell et al., 2001c.)