A new study has identified distinct periods of human brain development, with some reports suggesting four specific ages are crucial for brain maturity and others indicating the brain goes through five eras of development across a lifetime. The eras are reportedly associated with changes in brain wiring and structure, although the exact ages that mark these transitions are not consistently specified. The brain's development is said to continue through various stages, with one report suggesting that the adult stage may not begin until the early 30s.