“Origins of communicative disorders ” to Elizabeth Bates, and by a grant from the John D. and Catherine T. MacArthur Foundation. We are grateful to Larry Juarez and Meiti Opie The effects of focal brain injury are investigated in the first stages of language development, during the passage from first words to grammar. Parent report and/or free speech data are reported for 53 infants and preschool children between 10- 44 months of age. All children had suffered a single, unilateral brain injury to the left or right hemisphere, incurred before six months of age (usually in the pre- or perinatal period). This is the period in which we should expect to see maximal plasticity, but it is also the period in which the initial specializations of particular cortical regions ought to be most evident. In direct contradiction of hypotheses based on the adult aphasia literature, results from 10- 17 months suggest that children with righthemisphere injuries are at greater risk for delays in word comprehension, and in the gestures that normally precede and accompany language onset. Although there were no differences between left- vs. right-hemisphere injury per se on expressive language, children whose lesions include the left temporal lobe did show significantly greater delays in expressive vocabulary and

this paper we will examine one aspect of grammatical development in children who have undergone hemispherectomy to control intractable epilepsy. Our objective is to investigate language development in children who have undergone hemispherectomy, the removal of one hemisphere of the brain, as a way to gain insight into the potential of each cortical hemisphere to subserve grammatical development. A second objective is to provide evidence regarding whether and/or when their grammars include functional categories. The focus of this paper is the functional category INFL, which stands for `inflection', and subcategories of INFL, or I, for short. We will examine whether and how the grammars of children who have undergone right or left hemispherectomy embody the I-system. Note that after a left hemispherectomy a person has only a right hemisphere, and after a right hemispherectomy a person has only a left hemisphere. There are thus two main objectives, and two related sets of issues involved in this work: the neurolinguistic questions regarding the capacity of each hemisphere to subserve grammatical development and the theoretical acquisition issues regarding the principles operative in grammatical development. Specifically, we refer to whether the functional category systems are part of Universal Grammar and therefore are part of every natural grammar, child or adult. Let us first turn to the neurolinguistic questions and issues.

We analyzed post-surgery linguistic outcomes of 43 hemispherectomy patients operated on at UCLA. We rated spoken language (Spoken Language Rank, SLR) on a scale from 0 (no language) to 6 (mature grammar), and examined the effects of side of resection damage, age at surgery/seizure onset, seizure control post-surgery, and etiology on language development. Etiology was defined as developmental (cortical dysplasia and pre-natal stroke) and acquired pathology (Rasmussen's encephalitis and post-natal stroke). We found that clinical variables were predictive of language outcomes only when they were considered within distinct etiology groups. Specifically, children with developmental etiologies had lower SLRs than those with acquired pathologies (p=0.0006); age factors positively correlated with higher SLRs only for children with acquired etiologies (p=0.0006); right sided resections led to higher SLRs only for the acquired group (p = 0.0008); and post-surgery seizure control positively corre...

Development and early focal brain injury 2 Over the past ten years, we have made significant progress in addressing key questions concerning deficit and development after early stroke. We found evidence of subtle early impairment and subsequent development in each domain examined. However, the profiles of impairment and development differed across domains. Deficits of language acquisition are initially pervasive in that they are observed following injury to widely distributed brain areas. Spatial analytic deficits exhibit more specific patterns of brain-behavior association, similar to those observed among adults with injury to comparable brain regions. Had we been working in isolation, the separate investigators associated with this project may have reached very different conclusions about the nature of development following early injury. Instead, we were forced to look for ways to resolve the apparent disparity in our cross-domain findings. The model that best fits our data focuses on redefining the nature of early plasticity. Recent animal studies provide strong evidence that plasticity plays a central role in brain development. Brain organization is to a large extent

Children with early brain damage, unlike adult stroke victims, often go on to develop nearly normal language. However, the route and extent of their linguistic development are still unclear, as is the relationship between lesion site and patterns of delay and recovery. Here we address these questions by examining narratives from children with early brain damage. Thirty children (ages 3;7–10;10) with preor perinatal unilateral focal brain damage and their matched controls participated in a storytelling task. Analyses focused on linguistic proficiency and narrative competence. Overall, children with brain damage scored significantly lower than their age-matched controls on both linguistic (morphological and syntactic) indices and those targeting broader narrative qualities. Rather than indicating that children with brain damage fully catch up, these data suggest that deficits in linguistic abilities reassert themselves as children face new linguistic challenges. Interestingly, after age 5, site of lesion does not appear to be a significant factor and the delays we have witnessed do not map onto the lesion profiles observed in adults with analogous brain injuries. 1998 Academic Press More than 120 years ago, research on the effects of unilateral brain injury in adults led to the conclusion that the left hemisphere plays a specialized The research reported here has been supported by NINDS-NIH Grant P250-NS-22343 and NIDCD Grant R29 DC00539. We also thank Judi Fenson, Gretchen Chapman, and Shelley Flores for their help in data collection and transcription as well as the families who have graciously participated in this study. Address correspondence and reprint requests to Judy Snitzer Reilly, San Diego State University,