The interface between neighborhood density and optional infinitives: Normal development and Specific Language Impairment

The effect of neighborhood density on optional infinitives was evaluated for typically developing (TD) children and children with Specific Language Impairment (SLI). Forty children, 20 in each group, completed two production tasks that assessed third person singular production. Half of the sentences in each task presented a dense verb, and half presented a sparse verb. Children's third person singular accuracy was compared across dense and sparse verbs. Results showed that the TD group was significantly less likely to use optional infinitives with dense, rather than sparse verbs. In contrast, the distribution of optional infinitives for the SLI group was independent of verb neighborhood density. Follow-up analyses showed that the lack of neighborhood density effect for the SLI group could not be attributed to heterogeneous neighborhood density effects or floor effects. Results were interpreted within the Optional Infinitive/Extended Optional Infinitive accounts for typical language development and SLI for English speaking children.National Institutes of Health DC00433, RR7031K, DC00076, DC001694 (PI: Gierut

Do Word-Level Characteristics Predict Spontaneous Finiteness Marking in Specific Language Impairment?

The correct use of morphological suffixes in obligatory contexts reflects linguistic knowledge and competence of speakers. Grammatical knowledge is acquired during a child’s period of primary language acquisition, and may be partial or incomplete due to normal linguistic variation found during acquisition, due to a child’s level of progression through typical chronological development, or due to the presence of language disorders, like specific language impairment (SLI). In the current study, we ask whether characteristics of verbs make it more or less likely that children will correctly use an inflectional morpheme. The morphemes of interest in the current study were third person singular –s (3S) and past tense –ed (ED). Data for analysis were taken from a database of spontaneous language samples collected from 40 children (20 with SLI and 20 developing typically; Hoover, Storkel, & Rice, 2012). Spontaneous language samples were analyzed for the presence or absence of each morpheme in obligatory contexts. For each word item, the uninflected base word was additionally analyzed for a number of phonological and lexical variables. After comparing children with SLI to typically developing peers group differences emerged with respect to the effect of phonological and lexical variables. Moreover, different variables were determined to predict the 3S and ED morphemes. The results are discussed highlighting relevant theoretical and clinical implications

Grammatical treatment and specific language impairment: Neighbourhood density & third person singular –s

This is the author's accepted manuscript. The original publication is available at http://www.tandfonline.com/doi/full/10.3109/02699206.2013.789928The purpose of this study was to test the effect of manipulating verb neighbourhood density in treatment targeting the third person singular lexical affix. Using a single-subject experimental design, 6 pre-schoolers with Specific Language Impairment (SLI) were randomly assigned to one of two conditions: 1) treatment with sparse verbs or 2) treatment with dense verbs in 12 sessions. The third person singular lexical affix was targeted for 12 sessions of treatment in both conditions. Treatment gain and generalization were measured as the dependent variables. Third person singular % correct change from pre-treatment to post-treatment was measured using sentence production tasks with comparisons across the two treatment conditions. Treatment gain and generalization were greater for children enrolled in the sparse condition. Preliminary clinical recommendations are made and theoretical implications are discussed relative to neighbourhood density effects on lexical activation and storage in children with SLI

Grammatical treatment and specific language impairment: Neighborhood density & third person singular -s

The purpose of this study was to test the effect of manipulating verb neighbourhood density in treatment targeting the third person singular lexical affix. Using a single-subject experimental design, 6 pre-schoolers with Specific Language Impairment (SLI) were randomly assigned to one of two conditions: 1) treatment with sparse verbs or 2) treatment with dense verbs in 12 sessions. The third person singular lexical affix was targeted for 12 sessions of treatment in both conditions. Treatment gain and generalization were measured as the dependent variables. Third person singular % correct change from pre-treatment to post-treatment was measured using sentence production tasks with comparisons across the two treatment conditions. Treatment gain and generalization were greater for children enrolled in the sparse condition. Preliminary clinical recommendations are made and theoretical implications are discussed relative to neighbourhood density effects on lexical activation and storage in children with SLI.National Institutes of Health DC00433, RR7031K, DC00076, DC001694 (PI: Gierut)This is an Accepted Manuscript of an article published by Taylor & Francis in Clinical Linguistics & Phonetics on September 2013, available online: http://wwww.tandfonline.com/10.3109/02699206.2013.789928

Finiteness Marking in Boys with Fragile X Syndrome

Purpose This study investigated finite marking (e.g., he walks, he walked) in boys with fragile X syndrome; the boys were grouped based on receptive vocabulary (i.e., borderline, or impaired vocabulary). Method Twenty-one boys with the full mutation of fragile X, between the ages of 8 to 16 years participated. The boys completed probes from the Test of Early Grammatical Impairment (Rice & Wexler, 2001), a language sample, a nonverbal IQ test (Leiter-R, Roid & Miller, 1997), a receptive vocabulary test (PPVT-IV Dunn & Dunn, 2007), and a measure of autistic symptoms (CARS; Schopler et al., 2002). Results There were group differences for finiteness responses on the third person singular probe; the group with impaired vocabulary omitted markers with greater frequency compared to borderline vocabulary group. There were not significant differences on the past tense probe, although boys with borderline and impaired vocabulary were delayed relative to language expectations. Nonverbal IQ was not correlated with the measures of finiteness marking. Conclusion Boys with FXS demonstrate delays in finiteness marking, in particular on past tense verbs. Boys with impaired vocabulary show a unique profile unlike children with SLI, in which their use of tense markers may exceed expectations benchmarked to clause length

Language growth and genetics of specific language impairment

Behavioural studies of children with specific language impairment (SLI) have reported long term growth outcomes across different dimensions of language. Genetic studies of children with SLI have identified candidate genes and putative associations of gene variants with SLI. The aims of this review are to summarize these two lines of investigation and to highlight the possible role of underlying growth timing mechanisms that influence the trajectory of language outcomes throughout childhood and into adolescence. Behavioural growth trajectories demonstrate that children with SLI have notable strengths in language acquisition, as well as limitations, across different dimensions of language. Language onset appears delayed, although the rate and pattern of change over time is similar to unaffected children. Growth rate decelerates early in adolescence for some dimensions of language. Genetic investigations reveal candidate genes that are known to influence neuronal development, and reveal possible gene interactions along a causal pathway. Epigenetic studies reveal other genetic influences implicated in the cognitive decline associated with aging. This review highlights possible parallels between underlying genetic mechanisms and characteristics of linguistic growth trajectories. The conclusion is that new developmental perspectives are needed to inform language intervention in ways that align nurture with nature

Effects of Verb Familiarity on Finiteness Marking in Children with SLI

Children must acquire multiple language dimensions to ultimately achieve adult levels of language competence. Two such language dimensions, finiteness marking and the verb lexicon, are considered areas of weakness in specific language impairment (SLI). Given these weaknesses, the question arises of whether these two dimensions are related in children with SLI and/or typically developing children. One way to examine this question is to assess the hypothesis that verb familiarity influences finiteness marking accuracy. A sentence imitation task was developed to examine this hypothesis. In sentence imitation tasks, a child is asked to repeat a sentence verbatim. Sentence imitation has been proposed as an index of children's generative use of grammar (Child Grammar Account). An alternative proposal is that sentence imitation measures verbal memory instead of language ability (Verbal Memory Account). The sentence imitation task employed in the current study allowed estimates of finiteness marking and the verb lexicon while examining whether verb familiarity influences finiteness marking. Imitations were coded and analyzed for overall sentence accuracy and deviations from the target sentence in individual clausal components (i.e., finiteness marking and the verb root). The coding system designed for this study also set up a comparison of the two proposed accounts of sentence imitation. Three groups of children completed the sentence imitation task: 20 children with SLI (5-years old), 23 age-equivalent control children (AE; 5-years old) and 16 language-equivalent control children (LE; 3-years old). The AE group was more accurate than each of the SLI and LE groups (who performed similarly) on overall sentence imitation accuracy, finiteness marking accuracy and verb root imitation accuracy. Familiar verbs conferred an advantage on overall sentence imitation, finiteness marking and verb root imitation accuracy as well. Results also reported group x condition interactions for finiteness marking and verb root imitation. Patterns of deviations from the target sentence support the Child Grammar Account of sentence imitation, but not the Verbal Memory Account. Overall, study findings are consistent with expectations based on the literature and support the proposal that verb familiarity affects finiteness marking

The Interface between the Lexicon and Finiteness Marking in Specific Language Impairment

Inconsistent omission of finiteness markers is a clinical marker for Specific Language Impairment (SLI). A similar pattern of omission is observed during normal development. Potential limiting factors during this stage of variability are not well understood. This research considered lexical representations, indexed by neighborhood density, as one limiting factor. Study 1 examined the effect of density on variable production of a finiteness marker by 4- and 5-year olds with SLI and by typically developing 3-year olds. The results showed that density was a limiting factor for typically developing children, but not for children with SLI. Study 2 examined the effect of density on finiteness growth in a learning task by children with SLI. Results showed differences in growth for children exposed to dense and sparse verbs. The combined results suggest that lexical representations interact with finiteness to differentially impact production and growth. Differences in density effects across groups are discussed

Person marking and information structure in Nakh-Daghestanian

[Extract] What is the function of person indexing? - reduplicating 'redundant' information - reference tracking in discourse - highlighting the grammatically privileged participant Characterization of person indexing: - trigger of the person indexing - position of person indexing Person indexing in Nakh-Daghestanian: - Nakh-Daghestanian (or East Caucasian or North-East Caucasian) languages are spoken in Northern part of the Caucasus (Russia, Azerbaijan, Georgia) - salient grammatical feature: gender/number agreement on verbs, partially on adjectives, adverbs - person indexing is not very frequent in Nakh-Daghestanian - overviews: Helmbrecht (1996), Schulze (2007a) - among the languages that have it are: Dargi, Lak, Tabasaran, Batsbi, Udi, and to a lesser extend Hunzib, Akhvakh and two Avar dialects - generally viewed as a relatively young category (in contrast to the pervasive and probably older gender/number indexing) - only one person is indexed (with the exception of Tabasaran) - indexing is regulated by various hierarchies - in Dargi, Lak, and Udi (Harris 2002: 44-63) person makers express term focus - focus (Dik et al. 1981) "what is relatively the most important or salient information in the given setting" - term focus (or constituent focus or argument focus): whenever the scope of focus is not on the predication as a whole, but on some part of it - two types of term focus: - completive (or presentational or information focus): the focus fills a gap in the pragmatic information of the addressee; new information (e.g. answers to WH-questions) - contrastive (or identificational): a reply to the addressee's contrary belief of information (e.g. correction by replacing, restricting or expanding), characterized by exhaustiveness (i.e. it implies that the predication holds only for the focused element out of a set of elements given in the context) (e.g. cleft constructions, prosodic prominence, focus particles