Perinatal Focal Brain Injury: Scope and Limits of Plasticity for Language Functions

Children with perinatal focal brain injury exhibit normal or near-normal language development even when lesions are large and encompass classic left hemisphere perisylvian language networks. Their language difficulties are much more subtle than those seen in adults with similar lesions. We review the literature on the effects of perinatal injury on language development, with a focus on the scope and limits of functional plasticity, the relation between biological characteristics of lesions and language input on functional plasticity, and potential mechanisms of language plasticity after early lesions. The literature on the plasticity for language functions after perinatal focal brain injury presents a challenge to theories that posit an immutable brain basis for language and is consistent with the view of a dynamic, plastic brain-a developing brain capable of responding to internal biological signals, including those associated with injury, and to information provided by the environment.