Abstract not found

Abstract not found

“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

Aphasia (defined as the loss or impairment of language abilities following acquired brain injury) is strongly associated with damage to the left hemisphere in adults. This well-known finding has led to the hypothesis that the left hemisphere is innately specialized for language, and may be the site of a specific "language organ". However, for over a century we have known that young children with left-hemisphere damage (LHD) do not suffer from aphasia, and in most studies do not differ significantly from children with right-hemisphere damage (RHD). This result provides strong evidence for plasticity, i.e., brain reorganization in response to experience, and constitutes a serious challenge to the language organ hypothesis. This chapter reviews the history of research on language outcomes in children vs. adults with unilateral brain injury, addressing some discrepancies in the literature to date, including methodological confounds that may be responsible for those discrepancies. It also reviews recent prospective studies of children with unilateral injury as they pass through the first stages of language development. Prospective studies have demonstrated specific correlations between lesion site and profiles of language delay, but they look quite different from lesionsymptom correlations in adults, and gradually disappear across the course of language development. The classic pattern of brain organization for language observed in normal adults may be the product rather than the cause of language learning, emerging out of regional biases in information processing that are relevant for language, but only indirectly related to language itself. If those

The aim of this research project was to study the first stages of cognitive, communicative and linguistic development in a group of Italian-speaking infants who had suffered focal brain lesions to the left or right hemisphere before the time when language acquisition would normally begin (i. e. prenatally or in the first months of life). This study is part of a continuing collaboration between laboratories in the USA and Italy, using many of the same inclusion and exclusion criteria to define the sample (Marchman et al. 1991, Thal et al. 1991a, Wulfeck et al. 1991), together with a parallel set of parental report instruments for the evaluation of early language and communication. The present study had a somewhat more limited focus than its

We present the first direct comparison of language production in brain-injured children and adults, using agecorrected z scores for multiple lexical and grammatical measures. Spontaneous speech samples were elicited in a structured biographical interview from 38 children (5-8 years of age), 24 with congenital left-hemisphere damage (LHD) and 14 with congenital right-hemisphere damage (RHD), compared with 38 age- and gender-matched controls, 21 adults with unilateral injuries (14 LHD, 7 RHD), and 12 adult controls. Adults with LHD showed severe and contrasting profiles of impairment across all measures (including classic differences between fluent and nonfluent aphasia). Adults with RHD (and three nonaphasic adults with LHD) showed fluent but disinhibited and sometimes empty speech. None of these qualitative or quantitative deviations were observed in children with unilateral brain injury, who were in the normal range for their age on all measures. There were no significant differences between children with LHD and RHD on any measure. When LHD children were compared directly with LHD adults using age-corrected z scores, the children scored far better than their adult counterparts on structural measures. These results provide the first systematic confirmation of differential free-speech outcomes in children and adults, and offer strong evidence for neural and behavioral plasticity following early brain damage. For more than 3000 years, we have known that

Principle of parallel neuronal constellations..................................................................4 Principle of coherent functional group of neurons........................................................5 Population coding paradigm.........................................................................................5 Neuronal cortex as multidimensional coding “Fourier- windows “..............................6 The proposal of fractal mechanism in the cortex.........................................................7 Phase detection in the Fourier transformation...............................................................9 Is the cortex a hologram-like processor?....….............................................................10 Neuroanatomical advantages of the neuronal Fourier hologram.................................11 Basic cognitive advantage of the neuronal Fourier hologram.....................................12 Fourier hologram versus associative net neuronal models..........................................12

What is Quantitative EEG- Kaiser- 1 Basic description of quantitative electroencephalography (EEG) in the context of neurotherapeutic application. Issues associated with spectral analysis of human EEG are discussed and an example quantitative EEG assessment report is provided.

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,