fMRI study of language lateralization in children and adults

TLDR

Language lateralization depends on handedness, pathology, and other factors, and its age‑related pattern—leftward increase in children and reversal in young adults—is not fully understood. The study aims to determine whether language lateralization continues to decline in older adults and to identify the age at which the trend reverses. Using fMRI with a verb generation task, the authors assessed language lateralization in 170 healthy right‑handed participants aged 5–67. Language lateralization rises from ages 5 to 20, plateaus 20–25, then gradually declines through 70. Hum Brain Mapp, 2005; © 2005 Wiley‑Liss, Inc.

Abstract

Abstract Language lateralization in the brain is dependent on family history of handedness, personal handedness, pathology, and other factors. The influence of age on language lateralization is not completely understood. Increasing left lateralization of language with age has been observed in children, while the reverse has been noted in healthy young adults. It is not known whether the trend of decreasing language lateralization with age continues in the late decades of life and at what age the inflection in language lateralization trend as a function of age occurs. In this study, we examined the effect of age on language lateralization in 170 healthy right‐handed children and adults ages 5–67 using functional MRI (fMRI) and a verb generation task. Our findings indicate that language lateralization to the dominant hemisphere increases between the ages 5 and 20 years, plateaus between 20 and 25 years, and slowly decreases between 25 and 70 years. Hum Brain Mapp, 2005. © 2005 Wiley‐Liss, Inc.