An In Depth Analyses of Specific Language Impairment as Compared to Other Developmental Disorders

Specific language impairment (SLI), defined as a disproportionate difficulty in learning language despite having normal hearing, intelligence, and no known neurological or emotional impairment, has been shown to share similar cognitive characteristics with individuals with attention deficit hyperactive disorder (ADHD). However, little research has investigated the dissimilarities in these two different developmental disorders. Children with SLI also show many similar symptoms with individuals diagnosed with dyslexia. The aim of these studies is to get a better understanding of cognitive differences between SLI and ADHD, and the cognitive similarities between SLI and dyslexia. Tests of both verbal and non-verbal measures of working memory, IQ, and academic performance were administered to all groups. It was hypothesized that children with SLI would perform worse on verbal measures due to their language deficits but perform better on non-verbal measures than children with ADHD. It was also predicted that children with SLI will perform similarly, but worse than children with dyslexia. Results from the SLI/ADHD experiment confirm this pattern: children with SLI performed poorer than children with ADHD on all verbal cognitive measures. When looking at the non-verbal measures of abilities, the SLI group outperformed the ADHD group on working memory and IQ scores but not academic performance scores. Results from the SLI/Dyslexia experiment also confirmed what was predicted. Children with dyslexia outperformed their SLI counterparts on all cognitive measures. A possible explanation for these finding is that there are fewer classroom-based programs designed specifically to support children with SLI