J. Bruce Tomblin

The Association of Reading Disability, Behavioral Disorders, and Language Impairment among Second‐grade Children

Children with language impairment (LI) have been shown to be at risk for reading disability (RD) and behavior disorder (BD). Previous research has not determined the specific pattern of these conditions associated with LI. This study sought to determine if the behavior disorder and reading problems represented different outcomes or if these conditions occurred together when found with LI. A group of 581 second-grade children, including 164 children with LI, were examined for spoken language, reading, and behavior disorder. The data for each of these areas were examined as dimensional traits and as clinical categorical traits. Reading and spoken language were found to be strongly correlated (r = .68); RD was found in 52 % of the children with LI and in only 9 % of the controls. Scores of parent ratings for BD were also significantly correlated with spoken language scores (r = .29). Clinical levels of BD were found in 29% of the children with LI and 19% of the controls. An examination of the co-occurrence of clinical levels of BD, RD, and LI showed BD in children with LI to be conditioned by the childs reading status. The data indicated that whereas RD was directly associated with BD, the association of LI with BD required the mediation of RD.

Current state of knowledge: Language and literacy of children with hearing impairment

The purpose of this paper is to provide a review of past and current research regarding language and literacy development in children with mild to severe hearing impairment. A related goal is to identify gaps in the empirical literature and suggest future research directions. Included in the language development review are studies of semantics (vocabulary, novel word learning, and conceptual categories), morphology, and syntax. The literacy section begins by considering dimensions of literacy and the ways in which hearing impairment may influence them. It is followed by a discussion of existing evidence on reading and writing, and highlights key constructs that need to be addressed for a comprehensive understanding of literacy in these children.

Epidemiology of specific language impairment : Prenatal and perinatal risk factors

The prenatal and perinatal risk factors likely to be associated with specific language impairment (SLI) were examined in this study. A review of existing research showed that there have been few studies on this topic. Among children with SLI, greater rates of near relatives with language learning problems has been found. Data obtained from a case-control study of 177 children with SLI and 925 children without sensory, developmental disorders, or language impairment were studied using a parental questionnaire concerning exposures during the prenatal and perinatal period for the index children. Differences between the children with SLI and controls were found for parental characteristics regarding education, positive history of language and learning problems, tobacco smoking, and breast feeding. No support was found for elevated rates of maternal exposure to disease or occupational chemical substances.

Exploring the language and literacy outcomes of pediatric cochlear implant users.

Objective The principal goal of this study was to investigate the relationship between language and literacy (i.e., reading and writing) skills in pediatric cochlear implant users. A peripheral objective was to identify the childrens skills that were in need of remediation and subsequently to provide suggestions for remedial programming. It was predicted that the robust language skills often associated with children who have cochlear implant experience would facilitate the development of literacy skills. It was further proposed that the language and literacy skills of pediatric cochlear implant users would approximate the language and literacy skills of children with normal hearing. Design Sixteen pediatric cochlear implant users’ language and literacy skills were evaluated and then compared with a reference group of 16 age-matched, normal-hearing children. All 32 participants were educated in mainstream classes within the public school system in the Midwest. The “Sentence Formulation” and “Concepts and Directions” subtests of the Clinical Evaluation of Language Fundamentals-3 test were used to evaluate receptive and expressive language skills. Reading comprehension was evaluated with the “Paragraph Comprehension” subtest of the Woodcock Reading Mastery Test. Performance measures for the writing analyses included productivity, complexity and grammaticality measures. Results Children with cochlear implants performed within 1 SD of the normal-hearing, age-matched children on measures of language comprehension, reading comprehension and writing accuracy. However, the children with cochlear implants performed significantly poorer than the children with normal hearing on the expressive “Sentence Formulation” subtest. The cochlear implant users also produced fewer words on the written narrative task than did the normal-hearing children, although there was not a significant difference between groups with respect to total words per clause. Furthermore there was a strong correlation between language performance and reading performance, as well as language performance and total words produced on the written performance measure for the children using cochlear implants. Conclusions The results of this study suggest that the language skills of pediatric cochlear implant users are related to and correlated with the development of literacy skills within these children. Consequently, the performance of the cochlear implant users, on various language and literacy measures, compared favorably to an age-matched group of children with normal hearing. There were significant differences in the ability of the cochlear implant users to correctly utilize grammatical structures such as conjunctions and correct verb forms when they were required to formulate written and oral sentences. Given this information, it would be appropriate for their educational or remedial language programs to emphasize the use and development of these structures.

Procedural Learning in Adolescents With and Without Specific Language Impairment

Deficits in procedural learning have been hypothesized to contribute to the language and in particular grammatical difficulties of individuals with specific language impairment (SLI). This study tested this hypothesis by examining serial reaction time (SRT) learning in adolescents with and without SLI. The SRT task involved blocks of random sequences and pattern sequences. Response times for correct trials showed that responses for both groups improved in the trial blocks containing the pattern sequence. Adolescents with SLI showed slower learning rates during the pattern learning in comparison to the controls. When the language impairment was defined in terms of grammar impairments similar slower learning rates were found, but when language impairment was based on vocabulary group differences were not found. The results suggest that deficits in procedural learning system may account for some of the individual differences in language and grammar learning as well as problems of individuals with SLI.

Association of Specific Language Impairment (SLI) to the Region of 7q31

FOXP2 (forkhead box P2) was the first gene characterized in which a mutation affects human speech and language abilities. A common developmental language disorder, specific language impairment (SLI), affects 6%-7% of children with normal nonverbal intelligence and has evidence of a genetic basis in familial and twin studies. FOXP2 is located on chromosome 7q31, and studies of other disorders with speech and language impairment, including autism, have found linkage to this region. In the present study, samples from children with SLI and their family members were used to study linkage and association of SLI to markers within and around FOXP2, and samples from 96 probands with SLI were directly sequenced for the mutation in exon 14 of FOXP2. No mutations were found in exon 14 of FOXP2, but strong association was found to a marker within the CFTR gene and another marker on 7q31, D7S3052, both adjacent to FOXP2, suggesting that genetic factors for regulation of common language impairment reside in the vicinity of FOXP2.

Individual differences in online spoken word recognition: Implications for SLI.

Thirty years of research has uncovered the broad principles that characterize spoken word processing across listeners. However, there have been few systematic investigations of individual differences. Such an investigation could help refine models of word recognition by indicating which processing parameters are likely to vary, and could also have important implications for work on language impairment. The present study begins to fill this gap by relating individual differences in overall language ability to variation in online word recognition processes. Using the visual world paradigm, we evaluated online spoken word recognition in adolescents who varied in both basic language abilities and non-verbal cognitive abilities. Eye movements to target, cohort and rhyme objects were monitored during spoken word recognition, as an index of lexical activation. Adolescents with poor language skills showed fewer looks to the target and more fixations to the cohort and rhyme competitors. These results were compared to a number of variants of the TRACE model (McClelland & Elman, 1986) that were constructed to test a range of theoretical approaches to language impairment: impairments at sensory and phonological levels; vocabulary size, and generalized slowing. None of the existing approaches were strongly supported, and variation in lexical decay offered the best fit. Thus, basic word recognition processes like lexical decay may offer a new way to characterize processing differences in language impairment.

Perception and production of Mandarin tones in prelingually deaf children with cochlear Implants

Objective: Mandarin is a lexical tone language in which four tones are crucial for determining lexical meanings. Acquisition of such a tone system may be challenging to prelingually deaf children with cochlear implants because, as recent studies have shown, cochlear implant devices are ineffective in encoding voice pitch information required for tone recognition. This study aimed to investigate Mandarin tone production and perception skills of children with cochlear implants. Design: Thirty prelingually deaf children with cochlear implants, ages 6;0 (yr;mo) to 12;6, participated. These children received their implants at an average age of 5;8, with a range from 2;3 to 10;3. The average length of their cochlear implant experience was 3;7, with a range from 1;7 to 6;5. Tasks of tone production and tone identification involved a pictorial protocol of 48 words containing the targeted tones in either monosyllabic or disyllabic forms. Results: The average scores for tone production was 53.09% (SD = 15.42), and for tone identification was 72.88% (SD = 19.68; chance level = 50%). Significant differences were found in the percentages across the production or identification of tone types or tone pairs. The children with exceptional performance in tone production tended to also perform well in tone identification. The childrens performance levels in tone identification and production were also discussed in relation to the factors of age at implantation and length of cochlear implant experience. Conclusions: The present results suggest that the majority of prelingually deaf children with cochlear implants did not master Mandarin tone production. However, a small group of participants demonstrated nearly perfect skills of Mandarin tone production in addition to tone perception. Thus, it is necessary to consider factors other than the devices limitations to explain these high levels of performance in the perception and production of Mandarin lexical tones.

Prevalence and Nature of Late-Emerging Poor Readers.

Some children demonstrate adequate or better reading achievement in early school grades, but fall significantly behind their peers in later grades. These children are often referred to as late-emerging poor readers. In this study, we investigated the prevalence and heterogeneity of these poor readers. We also examined the early language and nonverbal cognitive abilities of late-emerging poor readers. Participants were 493 children who were a subsample from an epidemiological study of language impairments in school-age children. In kindergarten, children were administered a battery of language, early literacy, and nonverbal cognitive measures. Word reading and reading comprehension achievement was assessed in second, fourth, eighth, and tenth grades. Latent transition analysis was used to model changes in reading classification (good vs. poor reader) across grades. Population estimates revealed that 13.4% percent of children could be classified as late-emerging poor readers. These children could be divided into those with problems in comprehension alone (52%), word reading alone (36%), or both (12%). Further results indicated that late-emerging poor readers often had a history of language and/or nonverbal cognitive impairments in kindergarten. Subtypes of poor readers also differed significantly in their profiles of language, early literacy, and nonverbal cognitive abilities in kindergarten. Results are discussed in terms of causal factors and implications for early identification.

Grammar predicts procedural learning and consolidation deficits in children with Specific Language Impairment

The Procedural Deficit Hypothesis (PDH) posits that Specific Language Impairment (SLI) can be largely explained by abnormalities of brain structures that subserve procedural memory. The PDH predicts impairments of procedural memory itself, and that such impairments underlie the grammatical deficits observed in the disorder. Previous studies have indeed reported procedural learning impairments in SLI, and have found that these are associated with grammatical difficulties. The present study extends this research by examining consolidation and longer-term procedural sequence learning in children with SLI. The Alternating Serial Reaction Time (ASRT) task was given to children with SLI and typically developing (TD) children in an initial learning session and an average of three days later to test for consolidation and longer-term learning. Although both groups showed evidence of initial sequence learning, only the TD children showed clear signs of consolidation, even though the two groups did not differ in longer-term learning. When the children were re-categorized on the basis of grammar deficits rather than broader language deficits, a clearer pattern emerged. Whereas both the grammar impaired and normal grammar groups showed evidence of initial sequence learning, only those with normal grammar showed consolidation and longer-term learning. Indeed, the grammar-impaired group appeared to lose any sequence knowledge gained during the initial testing session. These findings held even when controlling for vocabulary or a broad non-grammatical language measure, neither of which were associated with procedural memory. When grammar was examined as a continuous variable over all children, the same relationships between procedural memory and grammar, but not vocabulary or the broader language measure, were observed. Overall, the findings support and further specify the PDH. They suggest that consolidation and longer-term procedural learning are impaired in SLI, but that these impairments are specifically tied to the grammatical deficits in the disorder. The possibility that consolidation and longer-term learning are problematic in the disorder suggests a locus of potential study for therapeutic approaches. In sum, this study clarifies our understanding of the underlying deficits in SLI, and suggests avenues for further research.