In search of shared deficits underlying SLI and dyslexia in Chinese

Abstract

Children with Specific Language Impairment (SLI) are at heightened risk for dyslexia. Some studies have found SLI children with concomitant dyslexia poorer at discriminating fine-grained auditory stimuli; in separate samples of SLI and reading-impaired children, others have found poorer quality of phonological representations. We asked whether auditory frequency discrimination (FD), frequency modulation (FM) detection and speech gating, putative measures of these skills, could identify SLI children ‘at-risk’ for dyslexia. Cantonese-speaking children aged 5-6 years were classified as SLI+ (n=15), SLI- (n=22), NL+ (n=14), or NL- (n=18) (+ and – denote at-risk status for dyslexia; NL denotes Normal Language). Group differences were evident on FM: SLI+ and SLI- had worse thresholds than NL+ and NL-, which did not differ from each other. SLI- children performed significantly less well on speech gating than the NL+ group, but did not differ from NL- or SLI+. These results suggest that poor FM and poor phonological representations might characterize SLI but not ‘at-risk’ status for dyslexia in Cantonese-Chinese children.