Latent Semantic Analysis Discriminates Children with Developmental Language Disorder (DLD) from Children with Typical Language Development

Journal of Psycholinguistic Research - Computer based analyses offer a possibility for objective methods to assess semantic-linguistic quality of narratives at the text level. The aim of the...     

Language Organization and Reorganization in Epilepsy

The vast majority of healthy individuals are left hemisphere dominant for language; however, individuals with left hemisphere epilepsy have a higher likelihood of atypical language organization. The cerebral organization of language in epilepsy has been studied with invasive procedures such as Wada testing and electrical cortical stimulation mapping (ESM), and more recently, with noninvasive neuroimaging techniques such as functional magnetic resonance imaging (fMRI). Investigators have used these techniques to explore the influence of unique clinical features inherent in epilepsy that might contribute to the reorganization of language, such as location of seizure onset, age of seizure onset, and extent of interictal epileptiform activity. In this paper, we review the contribution of these and other clinical variables to the lateralization and localization of language in epilepsy, and how these patient-related variables affect the results from these three different, yet complementary methodologies. Unlike the abrupt language changes that occur following acute brain injury with disruption of established language circuits, converging evidence suggests that the chronic nature of epileptic activity can result in a developmental shift of language from the left to the right hemisphere or re-routing of language pathways from traditional to non-traditional areas within the dominant left hemisphere. Clinical variables have been shown to contribute to cerebral language reorganization in the setting of chronic seizure disorders, yet such factors have not been reliable predictors of altered language networks in individual patients, underscoring the need for language lateralization and localization procedures when definitive identification of language cortex is necessary for clinical care.     

Phonological Working Memory and Spoken Language Development in Young Children

This study investigated the relationship between phonological working memory and spoken language development in a large unselected sample of 4- and 5-year old children. Assessments were made of the language produced by the children on the Bus Story (Renfrew, 1969), a standard test of continuous speech. In this test, children listen to a story, which they then recount with the aid of visual clues. The amount of information recalled and the average length of the five longest utterances are taken as indices of children's expressive language abilities. Phonological working memory skills were indexed by memory span and the ability to repeat non-words. The ability to repeat non-words made a significant contribution to the variance in the children's speech independently of age, vocabulary knowledge, and nonverbal cognitive skills. The possible mechanisms by which skills assessed by phonological memory tasks may be linked to the development of speech production abilities are considered.     

Pragmatic Language Development in Language Impaired and Typically Developing Children: Incorrect Answers in Context

This study focussed on young children’s incorrect answers to pragmatically demanding questions. Children with specific language impairment (SLI), including a subgroup with pragmatic language difficulties (PLD) and typically developing children answered questions targeting implicatures, based on a storybook and short verbal scenarios. Ninety-seven children participated in this study: 30 children with SLI of whom 12 had PLD, 32 typically developing children aged 5–6 years and 35 aged 7–11 years. The incorrect answers produced by the children with SLI were similar in their use of context to those of the 5–6 year old, suggesting developmental delay. The children with PLD produced significantly more irrelevant answers than both the language impaired children without PLD and the typically developing groups and had most difficulty when the context was presented solely verbally. Results are discussed in relation to a cognitive theory of communication and the clinical implications.     

Gesture Reflects Language Development: Evidence From Bilingual Children

There is a growing awareness that language and gesture are deeply intertwined in the spontaneous expression of adults. Although some research suggests that children use gesture independently of speech, there is scant research on how language and gesture develop in children older than 2 years. We report here on a longitudinal investigation of the relation between gesture and language development in French-English bilingual children from 2 to 3 1/2 years old. The specific gesture types of iconics and beats correlated with the development of the children's two languages, whereas pointing types of gestures generally did not. The onset of iconic and beat gestures coincided with the onset of sentencelike utterances separately in each of the children's two languages. The findings show that gesture is related to language development rather than being independent from it. Contrasting theories about how gesture is related to language development are discussed.     

Functional Magnetic Resonance Imaging of Language in Epilepsy

Functional magnetic resonance imaging (fMRI) has revolutionized our understanding of functional networks and cerebral organization in both normal and pathological brains. In the present review, we describe the use of fMRI for mapping language in epilepsy patients prior to surgical intervention including a discussion of methodological issues and task design, comparisons between fMRI and the intracarotid sodium amobarbital test, fMRI studies of language reorganization, and the use of fMRI laterality indexes to predict outcome after anterior temporal lobectomy.     

Factors Involved in Learning Problems and Educational Delay in Children with Epilepsy

Educational delay was assessed in a group of children with epilepsy and co-morbid learning problems, and compared with a matched group of children with learning problems, but without epilepsy. In addition, delay in the academic skills reading/spelling and arithmetic was compared for the two groups. Moreover, the differential contribution for the development of learning problems of each of the following epileptic factors was inspected: type of epilepsy, seizure type, seizure frequency and type of AED-treatment. The ‘Groninger School Onderzoek’ (G.S.O.) was used to yield an objective measurement of school achievement. The first 24 children with a reconfirmed diagnosis of epilepsy and with co-morbid learning problems who were referred to our outpatient department for ‘epilepsy and learning disabilities’ were included in the study. Each child was matched to a control subject (children with learning problems, but without epilepsy). Matching was carried out for the potential confounding factors age, school-type, school-grade and intelligence. The measure for school achievement showed no significant differences between the two groups with a delay in both groups of approximately a half year. Also, no statistically significant difference was found with respect to achievement on the academic skills reading/spelling and arithmetic. The impact of several epileptic factors on the measurement of school achievement were analyzed. The analysis of type of epilepsy showed significant lower school achievement scores for the patients with idiopathic generalized epilepsy compared to the patients with localisation-related epilepsy. Further evaluation of this result shows that most of the patients, classified as idiopathic generalized epilepsy have a recent onset epilepsy, a high seizure frequency and are not yet satisfactorily controlled with antiepileptic therapy. The key factor contributing to learning problems in children with epilepsy is an ‘uncontrolled’ epilepsy, i.e., an epilepsy with high seizure frequency.     

Patterns of Memory Performance in Children with Controlled Epilepsy on the CVLT-C

Decreased memory skills have been reported in children with epilepsy. However, standardized instruments to evaluate learning and memory in children have been unavailable until recently. The present study was designed to assess memory patterns in children with epilepsy based on the California Verbal Learning Test-Children's Version (CVLT-C). The test was administered to 44 children with complex partial seizures and 21 children with generalized seizures between 8 and 13 years of age. Children in the study had been treated for epilepsy for at least 6 months, had well-controlled seizures on monotherapy, and had no evidence of anticonvulsant toxicity. Children with head injuries, learning disabilities, or hyperactivity were excluded. Test results did not reflect differences in memory performance based on seizure type. Scores for the entire sample indicated intact new learning, decreased intrusions and perseverative responses, and better short-term than long-term delayed recall. Recognition skills were stronger than long-term delayed recall skills and suggested that memory performance may be improved for these children when a multiple-choice format is available in academic settings.     

Left-Hemisphere Dominance for Motion Processing in Deaf Signers

Evidence from neurophysiological studies in animals as well as humans has demonstrated robust changes in neural organization and function following early-onset sensory deprivation. Unfortunately, the perceptual consequences of these changes remain largely unexplored. The study of deaf individuals who have been auditorily deprived since birth and who rely on a visual language (i.e., American Sign Language, ASL) for communication affords a unique opportunity to investigate the degree to which perception in the remaining, intact senses (e.g., vision) is modified as a result of altered sensory and language experience. We studied visual motion perception in deaf individuals and compared their performance with that of hearing subjects. Thresholds and reaction times were obtained for a motion discrimination task, in both central and peripheral vision. Although deaf and hearing subjects had comparable absolute scores on this task, a robust and intriguing difference was found regarding relative performance for left-visual-field (LVF) versus right-visual-field (RVF) stimuli: Whereas hearing subjects exhibited a slight LVF advantage, the deaf exhibited a strong RVF advantage. Thus, for deaf subjects, the left hemisphere may be specialized for motion processing. These results suggest that perceptual processes required for the acquisition and comprehension of language (motion processing, in the case of ASL) are recruited (or "captured") by the left, language-dominant hemisphere.     

Relative Clause Gap-Filling in Children with Specific Language Impairment

Children with Specific Language Impairment (SLI) have been observed to have production and perception difficulties with sentences containing long-distance dependencies, but it is unclear whether this is due to impairment in grammatical knowledge or in processing mechanisms. The current study addressed this issue by examining automatic on-line gap-filling in relative clauses, as well as off-line comprehension of the same stimulus sentences. As predicted by both knowledge impairment and processing impairment models, SLI children showed lack of immediate gap-filling after the relative clause verb, in comparison to a control group of typically developing children. However, on the off-line measure of comprehension of the same stimuli sentences, SLI children and TD children did not differ qualitatively. This finding is incompatible with knowledge impairment. We interpret the results to show that SLI children have impaired processing mechanisms (such as temporally delayed gap-filling) but are not impaired in their grammatical knowledge.     

Cortical Language Mapping in Epilepsy: A Critical Review

One challenge in dominant hemisphere epilepsy surgery is to remove sufficient epileptogenic tissue to achieve seizure freedom without compromising postoperative language function. Electrical stimulation mapping (ESM) of language was developed specifically to identify essential language cortex in pharmacologically intractable epilepsy patients undergoing left hemisphere resection of epileptogenic cortex. Surprisingly, the procedure remains unstandardized, and limited data support its clinical validity. Nevertheless, ESM for language mapping has likely minimized postoperative language decline in numerous patients, and has generated a wealth of data elucidating brain–language relations. This article reviews the literature on topographical patterns of language organization inferred from ESM, and the influence of patient characteristics on these patterns, including baseline ability level, age, gender, pathology, degree of language lateralization and bilingualism. Questions regarding clinical validity and limitations of ESM are discussed. Finally, recommendations for clinical practice are presented, and theoretical questions regarding ESM and the findings it has generated are considered.     

Assessing Effort During Neuropsychological Evaluation with the TOMM in Children and Adolescents with Epilepsy

Effort assessment is of particular importance in pediatric epilepsy where neuropsychological findings may influence treatment decisions, especially if surgical interventions are being considered. The present investigation examines the Test of Memory Malingering (TOMM) in 60 children and adolescents with epilepsy. The overall pass rate for the sample was 90%. TOMM scores were unrelated to age, though there was a significant correlation between TOMM Trial 2 scores and intelligence estimates. Overall, the TOMM appears to be a valid measure of effort in young epilepsy patients, though caution should be used when interpreting scores for those with very low IQ, especially if behavioral problems are also evident. Caution should also be exercised in interpreting scores in children with ongoing interictal epileptiform activity that may disrupt attention.     

Literacy Development Among Language Minority Background and Dyslexic Children in Finnish Orthography Context

This study examines the development of reading and writing from first to second grade in transparent orthography (Finnish) among three groups: language minority children (n = 49), Finnish children at risk of reading difficulties (n = 347), and Finnish speaking children (n = 1747). Findings indicated that reading and writing skills in the language minority group and the Finnish classmates’ group developed at the same level by the end of second grade, but the development of children at risk of reading difficulties was slower across time. This finding indicates that the transparency of written language has an effect on success in literacy development with language minority children.     

Word Detection in Sung and Spoken Sentences in Children With Typical Language Development or With Specific Language Impairment

Background: Previous studies have reported that children score better in language tasks using sung rather than spoken stimuli. We examined word detection ease in sung and spoken sentences that were equated for phoneme duration and pitch variations in children aged 7 to 12 years with typical language development (TLD) as well as in children with specific language impairment (SLI ), and hypothesized that the facilitation effect would vary with language abilities. Method: In Experiment 1, 69 children with TLD (7–10 years old) detected words in sentences that were spoken, sung on pitches extracted from speech, and sung on original scores. In Experiment 2, we added a natural speech rate condition and tested 68 children with TLD (7–12 years old). In Experiment 3, 16 children with SLI and 16 age-matched children with TLD were tested in all four conditions. Results: In both TLD groups, older children scored better than the younger ones. The matched TLD group scored higher than the SLI group who scored at the level of the younger children with TLD . None of the experiments showed a facilitation effect of sung over spoken stimuli. Conclusions: Word detection abilities improved with age in both TLD and SLI groups. Our findings are compatible with the hypothesis of delayed language abilities in children with SLI , and are discussed in light of the role of durational prosodic cues in words detection.     

MRI对儿童难治性、局灶性癫痫的临床诊断及预后判断

癫痫外科的临床病理研究表明,儿童局灶性皮质发育不良(FCD)及海马硬化是儿童难治性局灶性癫痫常见的致病因素。但在术前的常规的MRI检查中,这些结构上的异常经常被忽视,从而造成延误诊断。临床医生在阅片判断上的失误可能是一个原因,但癫痫的影像专业知识的不全面是重要因素。本文结合MRI技术在癫痫临床诊断领域的应用进展,阐述了儿童难治性、局灶性癫痫患者MRI影像中可能出现的结构性病变;重点阐述了临床易于忽视的局灶性皮质发育不良(FCD)及海马硬化的MRI研究、应用进展。     

癫痫儿童的智力结构及适应行为特点的初步研究

探讨癫痫儿童的智力结构及适应行为特点并进行相关因素分析。应用中国-韦氏儿童智力测验量表及儿童适应行为评定量表,进行智力测验及适应行为评定。结果癫痫儿童易出现智力及适应行为能力的缺陷,对于癫痫儿童的临床治疗,除积极控制癫痫发作外,应注重认知功能的保护,其中言语智力的开发及训练应给予特别关注,同时,也应注意社会心理因素对儿...     

MRI对儿童难治性、局灶性癫痫的临床诊断及预后判断

癫痫外科的临床病理研究表明,儿童局灶性皮质发育不良(FCD)及海马硬化是儿童难治性局灶性癫痫常见的致病因素.但在术前的常规的MRI检查中,这些结构上的异常经常被忽视,从而造成延误诊断.临床医生在阅片判断上的失误可能是一个原因,但癫痫的影像专业知识的不全面是重要因素.本文结合MRI技术在癫痫临床诊断领域的应用进展,阐述了儿童难活性、局灶性癫痫患者MRI影像中可能出现的结构性病变;重点阐述了临床易于忽视的局灶性皮质发育不良(FCD)及海马硬化的MRI研究、应用进展.