Shape Mapping of the Hippocampus in Young Children with Autism Spectrum Disorder

The left column (A and B) shows the group difference between the average hippocampal surfaces of the typically developing and ASD groups. The deformation from typically developing to ASD is painted as a flame scale (shown on the right of figure) onto the average surface of the typically developing group with inward deformation in cooler colors and outward deformation in warmer colors. The middle column (C and D) shows the group difference as reconstructed by using eigenvectors 2, 1, and 3 (in that order), selected on the basis of logistic regression analysis to best discriminate children with ASD and typically developing children. The right column (E and F) shows the group difference as reconstructed by using only eigenvector 2, the single eigenvector found to best distinguish between diagnostic groups. The similarity between the pattern of hippocampal shape deformity indicated by the empiric group difference (A and B) and the eigenvector reconstructions demonstrates how the eigenvector shape metrics represent group shape variation