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Background Given the integral role that verbs play in sentence production, understanding verb deficits is critical to clinical practice. Difficulties in sentence production are often directly related to an inability to retrieve argument structure information which, according to most theoretical accounts, is specified at a lexical level as part of the semantic representation of the verb. The presence of an argument complexity effect when retrieving verbs in isolation, i.e. increased difficulty with increasing number of arguments required by the verb, is considered evidence of the integral link between verbs and the ensuing structure. Recent reports, however, of relatively intact verb retrieval and impaired argument structure suggest that difficulties with verbs and argument structure may not always co-occur. One explanation for this is that lexical-syntactic information may be stored separately to lexical-semantic information at the lemma level and then differentially impaired. Aims To determine whether the presence of difficulties creating argument structure in a group of people with aphasia with verb-retrieval deficits consistently aligned with the underlying nature of their impairment, where semantic involvement resulted in argument structure difficulties and post-semantic impairment resulted in intact argument structure. This would provide evidence either to support or to challenge the view that argument structure is lexically specified. The presence of an argument complexity effect within the participants' single verb naming was also investigated to examine the relationship between verb argument information and any subsequent difficulties creating argument structure for sentence production. Methods & Procedures Verb retrieval and argument structure production were investigated in 12 people with aphasia with verb-retrieval deficits on single-word and sentence-production measures. Outcomes & Results Eight of the 12 participants presented with a semantic verb deficit (five semantic and three mixed semantic and phonological) and had difficulties in creating argument structure. Four participants presented with a phonological verb deficit. Of these, two had intact argument structure while two had impaired argument structure. An argument complexity effect in verb naming was seen in both groups. Conclusions & Implications Semantic verb-retrieval deficits consistently resulted in argument structure production difficulties, supporting the view that syntactic information is stored within the lemma. The presence of argument structure difficulties in two participants with phonological deficits; however, lends support for the separate coding of lexical-syntactic from lexical-semantic information at the lemma level, a factor that has both theoretical and clinical implications with respect to diagnosis and management. [ABSTRACT FROM AUTHOR]

Background Children with specific language impairment (SLI) often experience word-learning difficulties, which are suggested to originate in the early stage of word learning: fast mapping. Some previous research indicates significantly poorer fast mapping capabilities in children with SLI compared with typically developing (TD) counterparts, with a range of methodological factors impacting on the consistency of this finding. Research has explored key issues that might underlie fast mapping difficulties in children with SLI, with strong theoretical support but little empirical evidence for the role of phonological short-term memory (STM). Additionally, further research is required to explore the influence of receptive vocabulary on fast mapping capabilities. Understanding the factors associated with fast mapping difficulties that are experienced by children with SLI may lead to greater theoretically driven word-learning intervention. Aims To investigate whether children with SLI demonstrate significant difficulties with fast mapping, and to explore the related factors. It was hypothesized that children with SLI would score significantly lower on a fast mapping production task compared with TD children, and that phonological STM and receptive vocabulary would significantly predict fast mapping production scores in both groups of children. Methods & Procedures Twenty-three children with SLI (mean = 64.39 months, SD = 4.10 months) and 26 TD children (mean = 65.92 months, SD = 2.98) were recruited from specialist language and mainstream schools. All participants took part in a unique, interactive fast-mapping task whereby nine novel objects with non-word labels were presented and production accuracy was assessed. A non-word repetition test and the Peabody Picture Vocabulary Test-Fourth Edition (PPVT-IV) were also administered as measures of phonological STM capacity and receptive vocabulary, respectively. Outcomes & Results Results of the fast-mapping task indicated that children with SLI had significantly poorer fast mapping production scores than TD children. Scores from the non-word repetition task were also significantly lower for the SLI group, revealing reduced phonological STM capacity. Phonological STM capacity and receptive vocabulary emerged as significant predictors of fast mapping performance when the group data were combined in a multiple regression analysis. Conclusions & Implications These results suggest that the word-learning difficulties experienced by children with SLI may originate at the fast mapping stage, and that phonological STM and receptive vocabulary significantly predict fast mapping ability. These findings contribute to the theoretical understanding of word-learning difficulties in children with SLI and may inform lexical learning intervention. [ABSTRACT FROM AUTHOR]