senile change

例句：

1. 1. As people age, their physical abilities gradually decline.
   随着人们年龄的增长，他们的体力逐渐衰退。
2. 2. The elderly often experience a decline in cognitive function.
   老年人常常经历认知功能的下降。
3. 3. The senile changes in the brain can lead to memory loss and confusion.
   大脑的老年变化可能导致记忆力丧失和混乱。