Effect of phoneme variability on audio and audiovisual nonword repetition by children with language or reading impairment

Effect of phoneme variability on audio and audiovisual nonword repetition by children with language or reading impairment

First Author: Anna Ehrhorn -- University of South Carolina
Additional authors/chairs: 
Suzanne Adlof; Daniel Fogerty
Keywords: Dyslexia, Language impairment, Nonword Repetition, Working memory, Phonological processing
Abstract / Summary: 

Purpose: Children with dyslexia or specific language impairment (SLI) often show nonword repetition (NWR) difficulties. However, it is unclear whether the NWR difficulties of children with dyslexia or SLI result from the same processing limitation (e.g., problems encoding, maintaining, or retrieving phonological information). The process-based framework was assessed by manipulating phonetic variability of the stimuli (high vs. low). In addition, given that both groups have difficulty with audiovisual integration, we also investigated the presentation modality (audio-only vs. audiovisual) to determine if visual cues could disambiguate low-variability stimuli to facilitate NWR performance in children with and without dyslexia or SLI.

Method: Four groups of 7-9 year-old children (typically developing (TD), SLI-only, dyslexia-only, both SLI and dyslexia (SLI+DYS)) completed a NWR Task including 36 CVCVCV nonwords, half with low phonetic variability, and half with high phonetic variability. Half of the nonwords were presented in an auditory-only condition, and half were presented in an auditory-visual condition with a video of the speaker’s face.

Results: A significant interaction between modality and phonetic variability was found, whereby the benefit for audiovisual presentation was greater for nonwords with low phonetic variability. There was a significant main effect of group (TD> SLI-only and Dyslexia only > SLI+DYS) but no interactions with group.

Discussion: Children with SLI and children with dyslexia show impaired NWR relative to TD children. However, they are similarly affected by phoneme variability and presentation modality as TD and SLI+DYS children. Further analyses will examine the types of NWR production errors made by each group.