It's all about the pruning, of course.
Between ages 11 and 17, children's brain waves reduce significantly while they sleep, a new study found. Scientists think this change reflects a trimming-down process going on inside teenagers' brains during these years, where extraneous mental connections made during childhood are lost.
"When a child is born, their brain is not fully-formed, and over the first few years there's a great proliferation of connections between cells," said physiologist Ian Campbell of the University of California, Davis. "Over adolescence there is a pruning back of these connections. The brain decides which connections are important to keep, and which can be let go."
