Brown Bag du 22/06/17 à 11h30 Kevin Shapiro (Assistant Professor of Neurology, UCSF Medical Center and UCSF Benioff Children's Hospital)



Language acquisition and language disruption: Insights from brain injury

Language function depends on a well-defined network of brain areas in the perisylvian region of the dominant hemisphere (usually the left hemisphere in right-handed individuals). Damage to these areas in adults may result in marked impairments in speaking, writing, comprehension, and reading. By contrast, it is generally thought that infants with injuries affecting even large portions of the left hemisphere achieve normal or near-normal language skills—although careful neuropsychological studies suggest the persistence of subtle deficits, which have not been well-investigated. Moreover, in adults, the role of particular parts of the language network has historically been determined by observing the deficits produced by lesions to those areas: damage to the left inferior frontal gyrus disrupts language production and grammatical processing; damage to the medial temporal lobe disrupts semantic processing, and so forth. In children, the contribution of these brain areas to language learning is much less well understood, and the functional consequences of focal damage are practically unknown. The markedly different trajectories of language impairment and recovery after brain injury in children and adults suggests that even if in most cases language preferentially engages left hemisphere brain regions, early injury to this network can lead to an alternative organization of language in the brain. In this talk, I will discuss how inferences are made about localization of language function in adults within the framework of cognitive neuropsychology and cognitive neuroscience, using processing of knowledge about grammatical categories as an example. I will then explore how these methods can be applied to the study of language development in children with injuries due to neonatal encephalopathy and perinatal stroke.