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76 CHARACTERISTICS OF BRAIN AND BEHAVIORperisylvian cortices of the temporal and parietal lobes where the ALC subjects tendedto have increased gray matter density and decreased white matter density.Although the volumetric and voxel-based image analyses described abovetended to localize cortical tissue abnormalities to parietal lobe regions, we becameinterested in abnormalities on the overlying cortical surface of the brain. Thus, inanother study (Sowell et al., 2002a) we analyzed brain surface shape abnormalitiesin the same group of children, adolescents, and young adults with prenatalalcohol exposure and assessed relationships between cortical gray matter densityon the brain surface and brain shape (Sowell et al., 2002a). We carefully matchedbrain surface anatomy across individuals using CPM techniques. Understandingspatial and temporal relationships between brain shape on the one hand, and tissuedensity changes on the other hand, could help shed light on the biologicalprocesses contributing most to the brain dysmorphology in the individuals observedin earlier structural MRI studies.Results from this study revealed highly significant decreased brain surface extentor reduced brain growth in the ventral aspects of the frontal lobes most prominentin the left hemisphere. Further, we found increased gray matter density in the inferiorparietal lobe and posterior temporal lobe bilaterally (see figure 3-12). Theresults imply that brain growth continues to be adversely affected long after theprenatal insult of alcohol exposure to the developing brain. Children with severeprenatal alcohol exposure have been shown to be impaired on neurocognitive tasksof frontal lobe and perisylvian/parietal lobe functioning (Mattson & Riley, 1998).Thus, the brain regions most implicated, frontal and inferior parietal/perisylvian,may be consistent with neurocognitive deficits characteristic of individuals prenatallyexposed to alcohol.CPM Studies in Children With ADHDPrevious structural brain imaging studies of attention deficit/hyperactivity disorder(ADHD) have demonstrated subtle reductions in total brain volume and involumes of the right frontal lobe and caudate nucleus. Various conventional volumetricand voxel-based image analytic methods have been employed in these studies,but regional brain size and gray matter abnormalities had not previously beenmapped over the entire cortical surface in patients with ADHD. Thus, we conductedCPM studies in a group of 27 children and adolescents with ADHD and46 age- and gender-matched control subjects (Sowell et al., 2003b).As predicted, abnormal morphology was observed in the frontal cortices ofADHD subjects, with reduced regional brain size localized primarily to inferiorportions of dorsal prefrontal cortices bilaterally. Brain size was also reduced inanterior temporal cortices bilaterally. Gray matter density was prominently increasedin large portions of the posterior temporal and inferior parietal cortices