Fig. 6.

Growth rate decreases in initially fast-growing cortical areas. (A) To quantify changes over time, local growth rates (n = 27 measurements from 15 noninjured subjects) are plotted against midpoint PMA at 10 vertices on left (blue) and right (red) hemispheres. Growth rate decreases with PMA at vertices 3, 8, and 9 (early motor, somatosensory, and visual cortices) and 7 (insula). By contrast, vertices 1–2, 4–6, and 10 remain relatively constant. (B) Individual growth rates were also compared between a noninjured subject (Left) and a subject with bilateral grade III/IV IVH (Right). From Top to Bottom, surfaces are shown at approximately 30 wk, 34 wk, and 38 wk PMA. Growth rate from 30 wk to 34 wk is plotted on the 34-wk surface, and growth rate from 34 wk to 38 wk is plotted on the 38-wk surface. For the subject with IVH, growth rate is initially reduced in occipital (5, 9) and temporal (6) lobes, but later recovers to near noninjured levels. Rates at locations 1–10 in these specific individuals are denoted in A by blue stars (no injury) or black stars (IVH).