Thirty preschool children with specific language impairment (SLI) and 30 age-matched controls with normal language (NL) participated in a study to compare group performance and to examine the relationship between fast mapping and word learning and between comprehension and production of new words. The groups performed similarly on the fast-mapping task. The NL group comprehended and produced significantly more words than the SLI group, and did so in fewer trials. Language test scores did not predict word-learning performance for either group. Some children with SLI may need to hear a new word twice as many times as their NL peers before comprehending it and may need twice as many opportunities to practice producing the word before using it independently.

The results suggest that preschoolers with SLI may benefit from cues that highlight the phonological or semantic properties of words but that different cues may aid different aspects of word learning.

This study investigated the structure of working memory in young school-age children by testing the fit of three competing theoretical models using a wide variety of tasks. The best fitting models were then used to assess the relationship between working memory and nonverbal measures of fluid reasoning (Gf) and visual processing (Gv) intelligence. One hundred sixty-eight English-speaking 7–9 year olds with typical development, from three states, participated. Results showed that Cowan’s three-factor embedded processes model fit the data slightly better than Baddeley and Hitch’s (1974) three-factor model (specified according to Baddeley, 1986) and decisively better than Baddeley’s (2000) four-factor model that included an episodic buffer. The focus of attention factor in Cowan’s model was a significant predictor of Gf and Gv. The results suggest that the focus of attention, rather than storage, drives the relationship between working memory, Gf, and Gv in young school-age children. Our results do not rule out the Baddeley and Hitch model, but they place constraints on both it and Cowan’s model. A common attentional component is needed for feature binding, running digit span, and visual short-term memory tasks; phonological storage is separate, as is a component of central executive processing involved in task manipulation. The results contribute to a zeitgeist in which working memory models are coming together on common ground (cf. Cowan, Saults, & Blume, 2014; Hu, Allen, Baddeley, & Hitch, 2016).

Twenty preschoolers with specific language impairment (SLI) and 20 age matches with normal language (NL) participated in a study to determine whether phonological memory or semantic knowledge predicted word-learning success. Poor learners' performance was analyzed to investigate whether phonology or semantics contributed more to word-learning difficulty. Results suggest that existing lexical knowledge, as measured by the Peabody Picture Vocabulary Test (PPVT-III), and fast-mapping ability hold promise for identifying poor word learners, but individual PPVT-III scores must be compared with SLI group scores. Poor word learners comprehended most new words and showed sufficient semantic knowledge of their referents to draw them but had difficulty producing the words. Findings indicated that both semantics and phonology contribute to word-learning difficulty, with word production presenting the biggest hindrance to success.

The phonological memory skills of preschoolers with NL and SLI followed a similar developmental pattern, but the SLI group consistently scored significantly lower than the NL group. Overall, the NL group showed significantly better receptive vocabulary, with evidence that between-group differences increased at age 6. Neither short-term phonological memory nor receptive vocabulary predicted fast mapping comprehension or production performance, even though both have been shown to correlate with later stages of word learning.