The neural basis of language development: Changes in lateralization over age

Significance Two types of evidence suggest different pictures of how language is represented in the brain during development. Studies of the anatomy, physiology, and fMRI activation of the two hemispheres show that language is lateralized to the left hemisphere from birth. In contrast, damage to the left versus right hemisphere in young children is equally likely to result in language impairment, suggesting that language is bilaterally represented in early development. The present study resolves this paradox by examining fMRI language activation in different ways. While group averages show LH lateralization throughout development, young children show RH language activation that declines systematically with age. Most important, this RH activation in children represents a possible mechanism for explaining language recovery following early stroke.