Our brain matures as we sleep

Many of the changes in an adolescent brain making the transition to mature thinking and from childhood to adulthood occur during sleep, U.S. scientists say. It involves pruning away excess neuronal connections necessary in youth to recover from injury and adapt to changing environments but which can impair the efficient problem-solving and logical thinking required later in life, they said. "We've provided the first long-term, longitudinal description of developmental changes that take place in the brains of youngsters as they sleep," Irwin Feinberg, director of the University of California, Davis, Sleep Laboratory, said. "Our outcome confirms that the brain goes through a remarkable amount of reorganization during puberty that is necessary for complex thinking." These changes can be detected by measuring the brain's electrical activity in the same children over the course of time, a university release said Tuesday. The researchers said a rapid decline in that activity between the ages of 12 and 16-1/2 led them to conclude that the streamlining of brain activity -- or "neuronal pruning" -- required for adult cognition occurs together with the timing of reproductive maturity. "Discovering that such extensive neuronal remodeling occurs within this 4-1/2 year time frame during late adolescence and the early teen years confirms our view that the sleep EEG indexes a crucial aspect of the timing of brain development," Feinberg said.