New research by neuroscientists at the University of Cambridge has identified five key stages of human brain development.

The study, led by Cambridge MRC Cognition and Brain Sciences Unit, found “five epochs” of the brain structure as humans grow, mature and ultimately decline.

It compared the brains of 3,802 people between the ages of zero and 90 years old, using datasets of MRI diffusion scans, which map neural connections by tracking how water molecules move through brain tissue.

Dr Alexa Mousley, a Cambridge Gates Scholar who led the research, said: “We know the brain’s wiring is crucial to our development, but we lack a big picture of how it changes across our lives and why.”

The scientists have detected five broad phases of brain structure in the average human life, split up by four pivotal “turning points” between birth and death when our brains reconfigure.

Dr Mousley added:“These eras provide important context for what our brains might be best at, or more vulnerable to, at different stages of our lives.

"It could help us understand why some brains develop differently at key points in life, whether it be learning difficulties in childhood, or dementia in our later years.”

“Looking back, many of us feel our lives have been characterised by different phases. It turns out that brains also go through these eras,” added senior author Prof Duncan Astle, Professor of Neuroinformatics at Cambridge.

The first epoch, from infancy to about age nine, is defined by rapid network consolidation as connections rewire across the whole brain. At age nine the brain experiences a step-change in cognitive capacity.

The second epoch, known as adolescence, shows continued white-matter growth and increasingly refined communication networks, as measured by diffusion of water in scans.

Dr Mousley explained: “While puberty offers a clear start, the end of adolescence is much harder to pin down scientifically. Based purely on neural architecture, we found that adolescent-like changes in brain structure end around the early thirties.”

The longest era, that of adulthood, begins at age 32 where the brain architecture stabilises for about three decades. A turning point occurs around age 66, when health risks affecting the brain increase.

The final stage of brain development, which occurs around 83, is defined by a shift from global to local as the connectivity declines further subsequently resulting in an increased reliance on certain regions of the brain.

The study's findings may be key to understanding various neurological and mental health conditions. It was supported by Medical Research Council, Gates Foundation and Templeton World Charitable Foundation.