A thesis submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Doctor of Philosophy. Johannesburg, 2015. / FOXP2 is the gene product of the so-called “language gene” and is the only protein known to be involved in a monogenetic autosomally inherited language disorder. This disorder has been termed Speech-Language Disorder 1. In addition to the role it plays in language, FOXP2 is thought to be involved in cancer, autism and schizophrenia. FOXP2 is a member of the P subfamily of FOX transcription factors, the DNA-binding domain of which is the forkhead domain. The aim of this work was to investigate the binding mechanism of the FOXP2 forkhead domain and various DNA sequences in order to assess affinity and specificity. It was shown by surface plasmon resonance that the FOXP2 forkhead domain can recognise a variety of DNA sequences, including a novel sequence, identified by systematic evolution of ligands by exponential enrichment. This motif has not previously been reported as a binding motif of the FOXP2 forkhead domain. Kinetic analysis by surface plasmon resonance showed that the novel sequence, as well as other published cognate sequences, each binds to the FOXP2 forkhead domain with different rates and affinities. Molecular docking of the DNA sequences to the FOXP2 forkhead domain revealed that electrostatic interactions between positively charged amino acids and the DNA backbone, as well as basespecific interactions between His554 and the DNA appear to be key in determining rates and affinities of binding interactions of the FOXP2 forkhead domain and DNA. Based on these findings, three types of DNA-binding are proposed for the FOXP2 forkhead domain. These types are: low affinity, nonfunctional binding; moderate affinity, non-functional binding and high affinity, functional binding. It is probable that each type of binding serves to control the vii spatial location of the protein within the nucleus, as well as the local concentration of protein. The proposed mechanism of binding for the forkhead domain of FOXP2 may have a future impact on the binding and function of full length FOXP2.

No description available.

The overall aim of this study is to clarify the situation in school for children with language disorder from the parents’ perspective. Data were collected through five interviews with parents who have children of different ages and with various diagnosis within the language disorder spectra. A qualitative method based on a narrative inquiry was used and each interview was based on a interview guide with the following themes: the child’s difficulties, starting school, the school’s pedagogy, homework, action plans, participation and the future. Each story has its own themes, but there are also themes that are common in all interviews. One common theme in the parents’ stories is that school has a lack of knowledge when it comes to language disorder. The parents’ stories also centre on the experience of having a child with language disorder and on the extra pressure that this entails. Another shared theme is their worries about how their children will manage school and the school’s failure to take this concern seriously enough. Reading skills is an area where the parents experience that their children have difficulties. Additional subject-specific research is needed to provide school with the right tools to help children with language disorder to perform in school.

The purpose of this study was to examine the extent to which modifiability ratings and gains in narrative language, made through intervention over time with culturally and linguistically diverse children, aligned with the results of a diagnostic dynamic assessment of language. This study also examined the sensitivity and specificity of the dynamic assessment when response to language intervention was used as the primary indicator of language disorder (LD). A total of 32 culturally and linguistically diverse students from an elementary school in Utah participated in this study, with 17 students with LD and 15 students without LD. Students were administered a dynamic assessment of language and were then provided small group narrative-based language intervention for several weeks. Student progress was monitored each week by collecting narrative language samples. Modifiability ratings were also collected, which provided information on student learning potential. Progress monitoring gain scores from the first intervention session to the last intervention session and mean modifiability ratings were compared between children with and without language disorder. Logistic regression and receiver operator characteristic analyses were conducted to obtain classification accuracy information. The results of this study indicated that growth in narrative language due to intervention did not reflect the results of the dynamic assessment; however, modifiability scores, which measure a student's difficulty in learning language, aligned with the dynamic assessment results. Sensitivity was 94% and specificity was 71%. It is possible that a dynamic assessment of language may be a less biased approach to diagnose LD in culturally and linguistically diverse students.

Children with Developmental Language Disorder (DLD) are at risk for reading disability and academic failure, and there remains a lack of scientific consensus about the underlying deficits that may explain their language difficulties. This study examined how language ability predicts preschoolers' eye movements during a naturalistic storybook reading task, a possible indicator of comprehension processes in real-time. We used eye-tracking measures to examine comprehension processes in 49 preschoolers with wide-ranging language abilities, using language skill as a continuous predictor variable. Participants viewed and listened to a storybook presented on an eye-tracking computer. Portions of each illustration that corresponded with a noun phrase in the text were considered target images during the time course of the spoken referent. Eye-tracking analyses revealed that children had similar latency to target images regardless of language level. However, language ability was a significant predictor of proportion of fixations; children with higher language skills had more fixations on target images and less fixations on control images than children with lower language skills. These results suggest that children with lower language abilities attended to the story but did not sufficiently sustain attention to relevant images and continued to attend to extraneous images after the onset of spoken noun phrases. Speech-language pathologists and early childhood educators should be aware that children with language difficulties may need help identifying what is most important to attend to during shared storybook reading.

Children with lower language abilities, including children with Developmental Language Disorder (DLD) are at risk for persistent reading difficulties. Previous studies have demonstrated that children with lower language abilities display eye movements different from their typically developing peers while hearing nouns in a naturalistic storybook reading context. This study examined how language ability and various lexical characteristics interact with 4- and 5-year- olds' eye movements during a naturalistic storybook reading task. We used eye-tracking technology to measure eye movements of 49 preschoolers with variable language skill. The children looked at storybook pictures on an eye tracking computer while they listened to a narration of the story. Target areas of each illustration corresponded to verbs in the text (i.e., images of the subjects and objects referred to by the verb). Results revealed that all children, regardless of language ability, were more likely to be looking at the target images while a target verb was being spoken than when a different word was being spoken. This relationship grew stronger as language ability increased. Additionally, lexical variables (age of acquisition, number of syllables, concreteness, frequency, and occurrences in the story) also impacted the likelihood that children were looking at the target images. Because the interaction of each lexical variable, language ability, and time was different, clinical implications suggest that speech-language pathologists, early childhood educators, and parents should be aware of these interactions in selecting storybooks with specific word stimuli. Such careful consideration of word stimuli may help children identify what illustrations are important during shared storybook reading.

Children with developmental language disorder (DLD) struggle in a variety of social contexts. These children display different forms of social withdrawal, the most prevalent being shyness which is behaviorally manifested as reticence. The goal of the current study was to further explore the relationship between DLD and reticence in children using a revised set of items from the Teacher Behavior Rating Scale (TBRS). A total of 220 children participated in the study. A univariate analysis of variance (ANOVA) was used to determine if there were significant differences related to group, age, and gender on reticence. Findings revealed a significant difference based on group, indicating children with DLD demonstrate significantly higher levels of reticence; however, age and gender were not significant. Interaction effects between the three variables were also not significant. These findings replicated previously reported findings regarding reticence in children with DLD.

Syftet med denna uppsats är att öka kunskapen kring hur några lärare undervisar elever med språkstörning på låg-, mellan- och högstadiet. Syftet uppnås genom att intervjua lärare och på så sätt få svar på frågeställningarna: Hur anpassar lärarna undervisningen för elever med språkstörning samt vilka utmaningar upplever lärarna att eleverna har? Vilka assisterande verktyg har lärarna tillgång till och använder? I vilken utsträckning anser lärarna att de har kunskaper och tillgång till stöd för att anpassa undervisningen för elever med språkstörning? I undersökningen framkommer att lärarna gör anpassningar i klassrummet för att elever med språkstörning ska kunna nå kunskapsmålen, men att de känner sig osäkra på hur de på bästa sätt skall göra lämpliga anpassningar. De assisterande verktyg som eleverna har tillgång till är bland annat inläsningstjänst och talsyntes. Dessa assisterande verktyg upplevs av lärarna både som framgångsrika men samtidigt som problematiska då de kan innebära praktiska hinder och avleda uppmärksamheten. Trots att språkstörning påverkar både sociala relationer, skolnärvaro och självbild hos dessa elever upplever många lärare att de har bristande kunskap kring diagnosen språkstörning och framgångsrika arbetssätt.

O Distúrbio Específico de Linguagem é uma desordem de comunicação, que tem início na infância e caracteriza-se pelo atraso na aquisição e desenvolvimento da linguagem. O objetivo desta Tese é caracterizar o desempenho gramatical de crianças normais e com Distúrbio Específico de Linguagem a partir de uma amostra de fala espontânea. Participaram desse estudo 70 crianças, com idade entre 3.1 e 6.11 anos, residentes no município de São Paulo. Os participantes foram divididos em dois grupos: GC (grupo controle) composto por 35 crianças com desenvolvimento normal de linguagem e GP (grupo pesquisa) composto por 35 crianças com diagnóstico de Distúrbio Específico de Linguagem. Esta Tese foi dividida em três estudos. Os resultados do Estudo 1 indicaram que os grupos se diferenciaram quanto aos morfemas gramaticais e quanto a extensão média do enunciado em morfemas e em palavras. No Estudo 2, os resultados indicaram que os grupos se diferenciaram em todas as faixas etárias quando analisamos os substantivos. Verificou-se diferença nas demais classes de palavras na faixa etária de 5-6 anos. No Estudo 3 verificamos que os grupos apresentam diferenças significativas quando analisamos a morfologia verbal. Concluímos que os sujeitos do GP apresentaram desempenho muito inferior aos sujeitos do GC, principalmente na faixa etária de 5-6 anos, caracterizando um déficit gramatical importante. / Specific Language Impairment is a communication disorder that begins in early childhood and is characterized by the delay in both language acquisition and development. The aim of this Thesis was to characterize the grammatical performance of children with and without Specific Language Impairment based on a spontaneous speech sample. Seventy children, with ages ranging from 3.1 to 6.11 years and residing in the city of São Paulo, participated in this study. The participants were split into two groups: CG (control group) comprised 35 children with normal language development and RG (research group) comprised 35 children with Specific Language Impairment. This Thesis was divided into three studies. The results of Study 1 showed differences between the two groups regarding grammatical morphemes and mean length of utterance in morphemes and words. In Study 2, the results showed that the groups differed, in all ages, when analyzed by the perspective of the noun. For the remaining word classes, results were different between the groups only at 5-6 years. In Study 3 significant differences between the two groups were observed when the verbal morphology was analyzed. The conclusion is that subjects of the RG had worse performance than subjects of the CG, especially at 5-6 years of age, characterizing an important grammatical deficit for children with Specific Language Impairment.

O Distúrbio Específico de Linguagem é uma desordem de comunicação, que tem início na infância e caracteriza-se pelo atraso na aquisição e desenvolvimento da linguagem. O objetivo desta Tese é caracterizar o desempenho gramatical de crianças normais e com Distúrbio Específico de Linguagem a partir de uma amostra de fala espontânea. Participaram desse estudo 70 crianças, com idade entre 3.1 e 6.11 anos, residentes no município de São Paulo. Os participantes foram divididos em dois grupos: GC (grupo controle) composto por 35 crianças com desenvolvimento normal de linguagem e GP (grupo pesquisa) composto por 35 crianças com diagnóstico de Distúrbio Específico de Linguagem. Esta Tese foi dividida em três estudos. Os resultados do Estudo 1 indicaram que os grupos se diferenciaram quanto aos morfemas gramaticais e quanto a extensão média do enunciado em morfemas e em palavras. No Estudo 2, os resultados indicaram que os grupos se diferenciaram em todas as faixas etárias quando analisamos os substantivos. Verificou-se diferença nas demais classes de palavras na faixa etária de 5-6 anos. No Estudo 3 verificamos que os grupos apresentam diferenças significativas quando analisamos a morfologia verbal. Concluímos que os sujeitos do GP apresentaram desempenho muito inferior aos sujeitos do GC, principalmente na faixa etária de 5-6 anos, caracterizando um déficit gramatical importante. / Specific Language Impairment is a communication disorder that begins in early childhood and is characterized by the delay in both language acquisition and development. The aim of this Thesis was to characterize the grammatical performance of children with and without Specific Language Impairment based on a spontaneous speech sample. Seventy children, with ages ranging from 3.1 to 6.11 years and residing in the city of São Paulo, participated in this study. The participants were split into two groups: CG (control group) comprised 35 children with normal language development and RG (research group) comprised 35 children with Specific Language Impairment. This Thesis was divided into three studies. The results of Study 1 showed differences between the two groups regarding grammatical morphemes and mean length of utterance in morphemes and words. In Study 2, the results showed that the groups differed, in all ages, when analyzed by the perspective of the noun. For the remaining word classes, results were different between the groups only at 5-6 years. In Study 3 significant differences between the two groups were observed when the verbal morphology was analyzed. The conclusion is that subjects of the RG had worse performance than subjects of the CG, especially at 5-6 years of age, characterizing an important grammatical deficit for children with Specific Language Impairment.