Beverly Wulfeck

''Frog, where are you?'' Narratives in children with specific language impairment, early focal brain injury, and Williams syndrome

In this cross-population study, we use narratives as a context to investigate language development in children from 4 to 12 years of age from three experimental groups: children with early unilateral focal brain damage (FL; N=52); children with specific language impairment (SLI; N=44); children with Williams syndrome (WMS; N=36), and typically developing controls. We compare the developmental trajectories of these groups in the following domains: morphological errors, use of complex syntax, complexity of narrative structure, and types and frequency of evaluative devices. For the children with early unilateral brain damage, there is initial delay. However, by age 10, they are generally within the normal range of performance for all narrative measures. Interestingly, there are few, if any, side specific differences. Children with SLI, who have no frank neurological damage and show no cognitive impairment demonstrate significantly more delay on all morphosyntactic measures than the FL group. Quantitatively, on morphosyntactic measures, the SLI group clusters with those children with WMS who are moderately retarded. Together these data help us to understand the extent and nature of brain plasticity for language development and those aspects of language and discourse that are dissociable.

Differential effects of unilateral lesions on language production in children and adults

We present the first direct comparison of language production in brain-injured children and adults, using age-corrected 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 and 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.

Phenotypic profiles of language-impaired children based on genetic/family history☆

Although etiological influences in developmental language impairment (dysphasia) are not well defined, a significant increase of family aggregation for the disorder has been reported. We report data from a large cohort of language-impaired (LI) children participating in the San Diego longitudinal study in which we examined whether children with or without positive family histories show different phenotypic profiles. Due to the longitudinal design of the study, questions pertaining to change over time are also addressed. Second, a subgroup of the most impaired children were reevaluated to obtain additional information pertaining to family history and phenotypic outcome. Approximately 70% of the LI children met criteria for inclusion as family history positive, with fathers reporting a history of language or learning problems one and a half to two times as frequently as mothers. LI children with or without a positive family history were not significantly different on language skills or IQ. However, subjects having a positive family history for developmental language/learning problems were significantly lower in socioeconomic status and were rated by parents and teachers as having more attention-related behavior problems than their family history negative counterparts. Similarly, family history positive LI children performed more poorly on standardized academic tests as well as on tests of auditory processing and attention.

Production of complex syntax in normal ageing and alzheimer's disease

Abstract Word-finding difficulties are among the earliest symptoms of Alzheimers disease (AD), but most AD patients retain the ability to produce well-formed sentences until the late stages of their disease. This dissociation has been used to argue for a modular distinction between grammar and the lexicon. In this paper, we offer an alternative view. First, we show that grammatical production is impaired in AD patients when grammar is assessed under highly constrained conditions in a film description task. Furthermore, these grammatical deficits are comparable in some respects to the patterns of lexical impairment observed in this and other studies of AD; specifically, patients do not produce frank lexical or grammatical errors, but they do find it difficult to access the “best fit” between meaning and form. We propose that differences in the onset time for lexical and grammatical symptoms in AD are due not to a disconnection between modules, but to fundamental differences in the automaticity and/or acce...

Neurological and MRI profiles of children with developmental language impairment

Children with developmental language impairment (LI) are defined partly by the absence of other identifiable neurological diagnoses. Such children are generally considered to be neurologically normal, but no systematic studies of neurological function have been reported. We obtained detailed medical histories and conducted neurological examinations for 72 children aged 5 to 14 years with LI and 82 typically developing age‐matched control children. All the children took a standardized test of language, and those who were at least 8 years old and were willing to have brain MRI scans (35 children with LI and 27 control children) had scans. Analysis of developmental milestones from the medical histories revealed that children with LI were not only significantly later in speaking, but also mildly but significantly delayed in motor milestones, particularly walking. On neurological examination, abnormalities were found in 70% of the children with LI and only 22% of the control children. The most common abnormalities in the LI group included obligatory synkinesis, fine motor impairments, and hyperreflexia. The children with LI with the most abnormal neurological findings had the lowest language scores. Finally, 12 of 35 children with LI had abnormalities on their MRI scan, while none of the 27 control children had abnormal scans. Abnormal findings included ventricular enlargement (in five), central volume loss (in three), and white matter abnormalities (in four). These findings suggest that developmental LI is not an isolated finding but is indicative of more widespread nervous system dysfunction. Children with LI may need more comprehensive intervention programs than language therapy alone, depending on their other areas of dysfunction. Early identification of such problems may allow for more successful remediation.

Grammatical Morphology in Aphasia: Evidence from Three Languages

Aspects of grammatical morphology in Brocas and Wernickes aphasia were elicited under controlled conditions in three language groups: English, Italian and German. Results suggest that the agrammatism/paragrammatism distinction does not work well for richly-inflected languages. Language-specific ratios of closed class morphology were preserved even among non-fluent patients, with significantly more morphology produced by German and Italian patients. German and Italian patients were also much more likely to furnish the article before nouns--despite or perhaps because of the fact that articles are more complex and informative in those languages. Although patients assigned the correct article most of the time, there were a significant number of article errors (i.e. paragrammatic substitution). Error analyses showed that substitutions are not random, reflecting difficulty in access rather than loss. Substitutions were more common in German, where the complex case and gender markings on the article increase the probability of error. Within each language, error patterns were quite similar for Brocas and Wernickes aphasics. However, at a detailed level patient group differences in error production were detected. German Brocas aphasics tend to avoid difficult case forms by substituting a simpler, less-marked morphosyntactic frame. Wernickes aphasics try instead to produce the more marked, oblique constructions, resulting in a less conservative error pattern.

Neurologic, cognitive, and linguistic features of infants after early stroke

Fourteen infants who suffered early localized, unilateral cerebral infarction were studied to examine the neurologic status of these children, to investigate psychomotor, cognitive, and language abilities, and to examine relationships between behavior and lesion severity. The patients underwent a neurologic examination and were evaluated with the Bayley Scales of Infant Development and the Sequenced Inventory of Communication Development. Motor development was not significantly delayed despite the presence of hemiparesis in most infants (which correlated with lesion severity). There was no evidence of marked delay in global cognitive functioning but one-half of the children were delayed in psychomotor functioning. Evidence of receptive and/or expressive language delay also was observed in one-half of infants and toddlers.

Effects of generation mode in fMRI adaptations of semantic fluency: paced production and overt speech.

Verbal fluency is a widely used neuropsychological paradigm. In fMRI implementations, conventional unpaced (self-paced) versions are suboptimal due to uncontrolled timing of responses, and overt responses carry the risk of motion artifact. We investigated the behavioral and neurofunctional effects of response pacing and overt speech in semantic category-driven word generation. Twelve right-handed adults (8 females), ages 21-37 were scanned in four conditions each: paced-overt, paced-covert, unpaced-overt, and unpaced-covert. There was no significant difference in the number of exemplars generated between overt versions of the paced and unpaced conditions. Imaging results for category-driven word generation overall showed left-hemispheric activation in inferior frontal cortex, premotor cortex, cingulate gyrus, thalamus, and basal ganglia. Direct comparison of generation modes revealed significantly greater activation for the paced compared to unpaced conditions in right superior temporal, bilateral middle frontal, and bilateral anterior cingulate cortex, including regions associated with sustained attention, motor planning, and response inhibition. Covert (compared to overt) conditions showed significantly greater effects in right parietal and anterior cingulate, as well as left middle temporal and superior frontal regions. We conclude that paced overt paradigms are useful adaptations of conventional semantic fluency in fMRI, given their superiority with regard to control over and monitoring of behavioral responses. However, response pacing is associated with additional non-linguistic effects related to response inhibition, motor preparation, and sustained attention.

Neurologic profiles of infants and children after perinatal stroke

Twenty-nine children with a single, unilateral cerebral infarct acquired pre- or perinatally were examined subsequently for an average of 43 months. No consistent pre- or perinatal events were identified to explain the occurrence of the stroke. The children acquired motor milestones at nearly expected times, even in the presence of hemiparesis. In children older than 2 years of age, I.Q. scores all were within the normal range. More than one-half of the children experienced seizures at some time during the follow-up period. Good intellectual and functional motor outcome can be expected in children with isolated perinatal stroke.

Mechanisms of verbal memory impairment in four neurodevelopmental disorders

Profiles of verbal learning and memory performance were compared for typically developing children and for four developmental disorders characterized by different patterns of language functioning: specific language impairment, early focal brain damage, Williams Syndrome, and Down Syndrome. A list-learning task was used that allowed a detailed examination of the process of verbal learning, recall, and recognition (California Verbal Learning Test--Childrens Version). Distinct patterns of performance characterized the four disorders. These patterns were consistent with the language deficits typically seen in the disorders, with the exception of a dissociation seen in Williams Syndrome.