Online measures of basic language skills in children with early focal brain lesions

Twenty children with early focal lesions were compared with 150 age-matched control subjects on 11 online measures of the basic skills underlying language processing, a digit span task, and 6 standardized measures. Although most of the children with brain injury scored within the normal range on the majority of the tasks, they also had a disproportionately high number of outlier scores on the reaction time tests. This evidence for a moderate impairment of the basic skills underlying language processing contrasts with other evidence suggesting that these children acquire normal control of the functional use of language. Furthermore, these children scored within the normal range on a measure of general cognitive ability, suggesting that there is no particular sparing of linguistic functions at the expense of general cognitive functions. Using the MPD procedure (Valdés-Pérez & Pericliev, 1997), we found that the controls and the five clinical groups could be best distinguished with two measures of online processing (word repetition and visual number naming) and one standardized test subcomponent (the CELF Oral Directions subtest). The 12 children with left hemisphere lesions scored significantly lower than the 8 other children on the CELF-RS measure. Within the group of children with cerebral infarct, the nature of the processing disability could be linked fairly well to site of lesion. Otherwise, there was little relation between site or size of lesion and the pattern of deficit. These results support a model in which damage to the complex functional circuits subserving language leads to only minor deficits in process efficiency, because of the plasticity of developmental processes.     

Planning and problem solving skills following focal frontal brain lesions in childhood: analysis using the Tower of London.

Problem solving skills were investigated in children with focal lesions using the Tower of London test (TOL; Shallice, 1982). The scoring procedure was elaborated from previous studies to delineate separate processes contributing to overall performance in children. Thirty-one children with focal frontal pathology, 18 children with focal pathology in other brain regions (extra-frontal), 17 children with generalized pathology and 38 healthy children participated in the study. Results suggest a distributed network for problem solving skills, particularly cognitive flexibility and goal setting skills. Within the frontal group, children with lesions involving the right pre-frontal cortex had greatest problems with self-regulation, with rule breaks most common among this group. As these skills develop relatively early in comparison to other aspects of executive function, right pre-frontal regions may play a particularly important role in the development of executive skills in childhood, with damage to these regions rendering children vulnerable to a range of cognitive and social deficits.     

Unilateral brain lesions in childhood: performance on the Revised Token Test

Comprehension of connected language as assessed by the Revised Token Test (RTT) was studied in 17 children with left hemisphere lesions (LL) and 11 with right hemisphere lesions (RL). LL children's significantly lower performance on several subtests than left controls (LC) matched by age, sex, race, and social class appeared to be related to the memory demands of these subtests rather than the limited syntactic elements assessed by the RTT. LL subjects requested significantly more command repetitions than control or RL subjects and when a repetition was not requested LL subjects often responded with immediacy. Although RL children tended to perform lower than right matched controls (RC), these differences were not significant nor readily related to either the memory or specific linguistic structures assessed. RL subjects required fewer command repetitions than LL subjects and exhibited a significantly greater frequency of immediate responses than controls or LL subjects. While based on few children, a trend for LL children with retrorolandic lesions to perform more poorly than those with left prerolandic lesions was suggested. No systematic difference in performance was apparent for children with left cortical vs. left subcortical lesions or among discrete sites of lesions within the right hemisphere. Children with left lesions prior to 1 year of age performed no better and, in several instances, significantly poorer than LL patients sustaining lesions after 1 year of age. Among RL subjects, those sustaining lesions after 1 year of age had greater difficulty than those with lesion onset before 1 year of age, especially on linguistic elements which seemed to be dependent upon visual spatial properties. Further studies are needed to evaluate the comprehension of more complex linguistic structures among children with unilateral brain lesions as well as to study the role of more basic factors such as memory and attention in explaining the present findings.     

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.     

The bimodal bilingual brain: effects of sign language experience

Bimodal bilinguals are hearing individuals who know both a signed and a spoken language. Effects of bimodal bilingualism on behavior and brain organization are reviewed, and an fMRI investigation of the recognition of facial expressions by ASL-English bilinguals is reported. The fMRI results reveal separate effects of sign language and spoken language experience on activation patterns within the superior temporal sulcus. In addition, the strong left-lateralized activation for facial expression recognition previously observed for deaf signers was not observed for hearing signers. We conclude that both sign language experience and deafness can affect the neural organization for recognizing facial expressions, and we argue that bimodal bilinguals provide a unique window into the neurocognitive changes that occur with the acquisition of two languages.     

Early lexical development in children with focal brain injury

Early lexical development in 27 children with focal brain injury was studied cross-sectionally and longitudinally. Data were obtained from children between 12 and 35 months of age who acquired their lesion prenatally or within the first 6 months of life. Results for the group as a whole provide clear evidence for delays in lexical comprehension and production, and for a larger number of comprehension/production dissociations than would be expected by chance. In addition, a significant number of children were observed having unusual difficulty mastering predication and/or using an atypically high proportion of closed class words (suggesting reliance on holistic/formulaic speech). Analyses by lesion type revealed no effect of lesion size. Analyses according to side of lesion revealed that children with right-hemisphere damage produced a higher proportion of closed class words, suggesting heavy reliance on well-practiced but under-analyzed speech formulae. Children with left-hemisphere damage were slightly better in comprehension than children with right-hemisphere damage. In addition, left posterior lesions were associated with greater delays in expressive language, and delays were more protracted in children with left posterior damage. No differential effects of left posterior damage were found for lexical comprehension.     

The implications of childhood bacterial meningitis for language development.

Bacterial meningitis is a life threatening infection of the central nervous system. This illness is most prevalent early in life when the healthy child is rapidly acquiring language. This study investigated whether children with a history of bacterial meningitis were at risk for language difficulties post illness. Thirty post-meningitic children, aged between 9 years 0 months and 11 years 0 months, participated in this study. Each subject was administered a measure of non-verbal cognitive ability and a range of language tasks. These children performed poorly on applied language tasks, which tap skills used in effective discourse. These deficits occurred despite age appropriate performances on measures of linguistic/grammatical knowledge. These findings clearly illustrate that bacterial meningitis has implications for ongoing language development, which emphasises the importance of long term follow up. In developmental terms, this discrepancy between verbal knowledge and problem solving represents a dissociation between language skills which develop early in life and those which emerge later. This pattern of results suggests that bacterial meningitis may result in a delay in language development. A young age at illness was identified as an additional risk factor for adverse outcome. This study highlights the need to inform parents/guardians that post-meningitic children are at risk for experiencing language difficulties throughout childhood.     

Grammaticality sensitivity in children with early focal brain injury and children with specific language impairment

Grammaticality judgments and processing times associated with violation detection were examined in typically developing children, children with focal brain lesions (FL) acquired early in life, and children with specific language impairment (SLI). Grammatical sensitivity in the FL group, while below typically developing children, was above levels seen in children with SLI. Age effects were noted with developmental changes in sensitivity extending into adolescence. Developmental delays in grammatical processing were particularly pronounced for children with SLI, who showed sensitivity levels below those of younger typically developing children. Sensitivity to agreement violations was also protracted in the SLI group providing further evidence of the vulnerability of morphology, a pattern not unlike that seen in adult aphasics. Findings for the FL group provide compelling evidence of neural and behavioral plasticity in children with early unilateral brain injury. Moreover, results from these children underscore how very different compensatory organization may be compared to profiles seen in adult aphasics who have comparable lesions. In contrast, although it was expected that the SLI children would perform below the typically developing children, the disadvantage seen with respect to the FL group suggests that the underlying pathology responsible for SLI may be more pervasive and less plastic than the focal pathology of children with early brain damage.     

Productive use of the English past tense in children with focal brain injury and specific language impairment

In this study, 22 children with early left hemisphere (LHD) or right hemisphere (RHD) focal brain lesions (FL, n=14 LHD, n=8 RHD) were administered an English past tense elicitation test (M=6.5 years). Proportion correct and frequency of over-regularization and zero-marking errors were compared to age-matched samples of children with specific language impairment (SLI, n=27) and with typical language development (TD, n=27). Similar rates of correct production and error patterns were observed for the children with TD and FL; whereas, children with SLI produced more zero-marking errors than either their FL or TD peers. Performance was predicted by vocabulary level (PPVT-R) for children in all groups, and errors did not differ as a function of lesion side (LHD vs. RHD). Findings are discussed in terms of the nature of brain-language relations and how those relationships develop over the course of language learning.     

Age of acquisition effects on the functional organization of language in the adult brain

Using functional magnetic resonance imaging (fMRI), we neuroimaged deaf adults as they performed two linguistic tasks with sentences in American Sign Language, grammatical judgment and phonemic-hand judgment. Participants’ age-onset of sign language acquisition ranged from birth to 14 years; length of sign language experience was substantial and did not vary in relation to age of acquisition. For both tasks, a more left lateralized pattern of activation was observed, with activity for grammatical judgment being more anterior than that observed for phonemic-hand judgment, which was more posterior by comparison. Age of acquisition was linearly and negatively related to activation levels in anterior language regions and positively related to activation levels in posterior visual regions for both tasks.     

Reorganization of the cerebro-cerebellar network of language production in patients with congenital left-hemispheric brain lesions

Patients with congenital lesions of the left cerebral hemisphere may reorganize language functions into the right hemisphere. In these patients, language production is represented homotopically to the left-hemispheric language areas. We studied cerebellar activation in five patients with congenital lesions of the left cerebral hemisphere to assess if the language network is reorganized completely in these patients, i.e. including also cerebellar language functions. As compared to a group of controls matched for age, sex, and verbal IQ, the patients recruited an area not in the right but in the left cerebellar hemisphere. The extent of laterality of the cerebellar activation correlated significantly with the laterality of the frontal activation. We suggest that the developing brain reacts to early focal lesions in the left hemisphere with a mirror-image organization of the entire cerebro-cerebellar network engaged in speech production.     

Grammatical gender effects on cognition: implications for language learning and language use

In 4 experiments, the authors addressed the mechanisms by which grammatical gender (in Italian and German) may come to affect meaning. In Experiments 1 (similarity judgments) and 2 (semantic substitution errors), the authors found Italian gender effects for animals but not for artifacts; Experiment 3 revealed no comparable effects in German. These results suggest that gender effects arise as a generalization from an established association between gender of nouns and sex of human referents, extending to nouns referring to sexuated entities. Across languages, such effects are found when the language allows for easy mapping between gender of nouns and sex of human referents (Italian) but not when the mapping is less transparent (German). A final experiment provided further constraints: These effects during processing arise at a lexical-semantic level rather than at a conceptual level.     

The effects of a community-based literacy program on young children's language and conceptual development

Effects of a community-based literacy program on 1−, 2−, and 3-year-old children's language and conceptual development were assessed. University students were trained to teach Head Start parents effective methods for reading to their children. Families were randomly assigned to receive 18, 3, or 0 instructional visits. Results indicated that parents in the 18-instructional-visit program increased their participation in appropriate literacy behaviors such as reading to their children, teaching concepts to their children, and using the library, more than parents in the 0-instructional-visit groups. Children in the 18-instructional-visit program showed greater gains in language and conceptual development than children in the 0-instructional-visit group. Few differences were found between children in the 3-visti and 0-instructional-visit groups. Thus, only a high-intensity community-based intervention designed to train parents was effective in increasing emergent literacy in low-income ethnic children. Supported by Commission on National and Community Service grant 92HELOCA0039, the Dr. Seuss Foundation, Head Start, and the College of Sciences at San Diego State University. The authors gratefully acknowledge William A. Hillix, Leah K. Gensheimer, and Larry Fenson for their helpful reviews of drafts of this article, Florence Goldman for her training of tutors in techniques for developing emergent literacy, and the many students who assisted in the implementation and evaluation of this project.     

Effects of receptive language training on receptive and expressive language development

The effects of a six-month training program in receptive language on receptive and expressive language development were investigated. Developmentally retarded preschoolers were pretested and posttested on one standardized test of receptive language and two tests of expressive language. Both the training and control groups participated in a preschool program. In addition, the training group received a two-sequence training program: (1) reinforcement for matching responses to modeling cues and accompanying verbal requests, and (2) reinforcement for appropriate responses to verbal requests alone. The training group demonstrated a significant increase in appropriate responses to verbal request over base-rate performance after the training and also demonstrated a significantly improved posttest performance on one test of expressive language as compared to the control group.The authors wish to thank Mrs. Helen Huggins and the staff of the Aid to Retarded Children's Preschool Training Center, San Francisco, California, for their assistance in this study. A modified version of this paper was presented at the Gatlinburg Conference on Mental Retardation, March, 1974, Gatlinburg, Tennessee.