Factors that influence lexical and semantic fast mapping of young children with specific language impairment

This purpose of this study was to investigate the lexical and semantic fast mapping ability of young children with specific language impairment (SLI) and normal language (NL), with a specific emphasis on the influence of phonological factors.

The study included 46 children (mean age 58 months), half with SLI and half with NL. Children were asked to fast map visual information only, visual-plus-nonlinguistic-auditory information, and visual-plus-linguistic-auditory information. A mixed design was used to compare children across and within groups.

Children with SLI performed worse than children with NL overall. The SLI group showed specific deficits in semantic fast mapping when they saw visual information only. This condition may have disrupted encoding because it varied from the expected auditory and visual pattern. The children with SLI also performed poorly when they were asked to map phonotactically infrequent linguistic information and when the difficulty of the task increased. A nonword repetition task was correlated with both semantic and lexical fast mapping.

The findings are discussed in the light of their support for a limited capacity model of processing, as well as the impact of phonology on word learning.