The Brain That Changes Itself: Stories of Personal Triumph from the Frontiers of Brain Science

by Norman Doidge

Another major reorganization of the brain occurs as we age. As we have seen, many brain activities are “lateralized.” Much of speech is a left-hemispheric function, while visual-spatial processing is a right-hemispheric function, a phenomenon called “hemispheric asymmetry.” But recent research by Duke University’s Roberto Cabeza and others shows that some lateralization is lost as we age. Prefrontal activities that took place in one hemisphere now take place in both. While we don’t know for sure why this happens, one theory is that as we age and one of our hemispheres starts to become less effective, the other hemisphere compensates—suggesting that the brain restructures itself in response to its own weaknesses.

less task hemispheric isolation (lateralization) as we age. Likely due to resource effectiveness compensation.