Specific Language Impairment and Reading Disability: Categorical Distinction or Continuum?

Specific language impairment (SLI) and reading disability (RD) are familial, moderately heritable comorbid developmental disorders. The key deficit of SLI is oral language, whereas children with RD exhibit impairment in learning to read. The present study examines the possible co-occurrence of RD and SLI and the nature of this co-occurrence at a linguistic and a cognitive level in an orthographically consistent language. Four groups of children participated in the study: an RD group ( n = 10), an SLI group ( n = 13), a possible comorbid group ( n = 9), and a control-no deficit group ( n = 20). Analysis showed that all three clinical groups in our sample performed similarly in phonological awareness and naming-speed tasks. However, significant group differences were observed in orthographic processing, reading, semantics, and phonological memory measures, thus supporting the view that SLI and RD are distinct disorders. Results are in line with previous findings indicating that SLI and RD share common characteristics, although the two conditions are manifested with different symptoms.

How Is RAN Related to Reading Fluency? A Comprehensive Examination of the Prominent Theoretical Accounts.

We examined the prominent theoretical explanations of the RAN-reading relationship in a relatively transparent language (Greek) in a sample of children (n = 286) followed from Grade 1 to Grade 2. Specifically, we tested the fit of eight different models, as defined by the type of reading performance predicted (oral vs. silent word reading fluency), the type of RAN tasks (non-alphanumeric vs. alphanumeric), and the RAN effects (direct vs. indirect). Working memory, attention, processing speed, and motor skills were used as "common cause" variables predicting both RAN and reading fluency and phonological awareness and orthographic processing were used as mediators of RAN's effects on reading fluency. The findings of both concurrent and longitudinal analyses indicated that RAN is a unique predictor of oral reading fluency, but not silent reading fluency. Using alphanumeric or non-alphanumeric RAN did not particularly affect the RAN-reading relationship. Both phonological awareness and orthographic processing partly mediated RAN's effects on reading fluency. Theoretical implications of these findings are discussed.

Memory functioning and mental verbs acquisition in children with specific language impairment.

Memory and language operate in synergy. Recent literature stresses the importance of memory functioning in interpreting language deficits. Two groups of 50 children each, ages 8-12 were studied. The first group included children with specific language impairment, while the participants in the second group were typically developing children. The two groups, which were matched on age, nonverbal intelligence and varied significantly in verbal ability were examined, using a test battery of four memory functioning (phonological, working and long-term memory) and five mental verb measures. The statistical analyses indicated that the two groups differed significantly in all language and memory measures; a logistic regression analysis revealed that within each main group existed nested subgroups of different developmental patterns with working and long-term memory measures as the most robust discriminate markers of classification. Language impaired children had more difficulties in the acquisition of mental verbs because they are less able to process and store phonological information in working memory and long-term lexicon.