For this research, neuroscientists analysed diffusion MRI scans of 3,802 individuals, ranging from infancy to 90 years old. By tracking how water moves through brain tissue, scientists mapped the brain’s neural connections over time. Instead of a gradual, linear transformation, they observed four “turning points” that break life into five broad “epochs” of brain structure and wiring. Each epoch corresponds to a distinct way the brain is organized — with different strengths, vulnerabilities, and patterns of change.
When do these “eras” appear?
According to the research — led by the University of Cambridge team and published in Nature Communications — the five broad phases are separated by four turning points at roughly 9, 32, 66, and 83 years, and they reveal how our mental wiring transforms from childhood into old age.
The eras are: (1) Childhood (birth to ~9), (2) Adolescence/young adulthood (~9–32), (3) Adult/prime (~32–66), (4) Early aging (~66–83), and (5) Late aging (83+).
However, it’s important to note that these are population averages, not exact cut-offs — people vary. The finding was summarised by the University of Cambridge team that led the study.