The Brain’s Five Phases

The Brain’s Five Phases

For the first time, scientists have identified four ages at which the average human brain rewires: ages 9, 32, 66, and 83. The resulting transitions provide five distinct stages of human brain development, according to a new study released yesterday.

Researchers studied roughly 3,800 people, from babies to individuals age 90, using MRI diffusion scans to examine how water molecules move through the brain. They saw that from birth to age 9 (childhood), gray and white matter rapidly increase, and extra synapses are pruned. From age 9 to age 32 (adolescence), white matter continues to grow, and cognitive performance improves. From 32 to 66 (adulthood), brain architecture stabilizes, leaving personality and intelligence mostly unchanged. Early aging begins at age 66, when neural activity is largely concentrated in subnetworks, and late aging begins at age 83, when connectivity decreases further. 

The findings suggest cognition doesn’t simply increase until a certain age and then decline. Read the full study here