Table 1.

Definitions and meanings of the six morphological measures

Morphological measures	Definitions	Meanings
Cortical thickness	The closest distance between the white and pial surfaces at each vertex on the cortical surface	Reflects dendritic arborization (Huttenlocher, 1990)
Surface area	The average area of the triangles that touch the vertex on the pial surface	Linked to the number of minicolumns in the cortical layer (Rakic, 1988)
GM volume	The sum of the volumes of the individual triangles that lie within the neighborhood of the vertex	A product of the thickness and surface area
Sulcal depth	The displacement from each vertex to the sulcal surface	The degree of cortical folding
Metric distortion	The degree of displacement and convolution of the cortical surface relative to the average template	The degree of cortical folding
Mean curvature	1/r (r is the radius of an inscribed circle)	Reflects folding of the small secondary and tertiary folds in the surface