The brain is thought to trim back neural connections as it develops, but scientists report that the region we rely on to recognize faces continues to increase in size into adulthood.
Kalanit Grill-Spector at Stanford University in California and her colleagues measured the brains of 22 children and 25 adults using functional and quantitative magnetic resonance imaging. The area of the brain that recognizes places stayed the same during development. But the brain tissue in the posterior fusiform gyrus, which is involved in facial recognition, grew in relative size with age. This change correlated with improved performance in facial-recognition tests in the adults compared with the children.
The authors suggest that these changes are caused by increases in branch-like neuronal structures called dendrites and other cellular anatomical shifts, rather than just an increase in the number of brain cells.