Contraction of front and side parts as cells die off was observed in some subjects in their thirties, but it was still not evident in some sixty and seventy-year-olds.

随着细胞的死亡，有些人大脑前部和侧部的收缩，在三十多岁时就能被观察到，但是也有些人直到六七十岁依然不明显。