Investigation of Procedural Memory in Persian-Speaking Children with Specific Language Impairment (SLI)

According to the Procedural Deficit Hypothesis (PDH) abnormalities in brain structures underlying procedural memory, largely explain language deficits in children with specific language impairment (SLI).The PDH assumes that the procedural memory affects the learning of grammar but the lexical knowledge is not affected. This study aims to examine the procedural memory and its relationship with language skills, in particular with grammar, in children with SLI. Methods and Materials: In this case-control study, We investigated the performance of 9 children with SLI and 9 typically developing children on a number of language and memory tasks. Children with SLI were chosen from speech therapy clinics in Mashhad. The typically developing children selected randomly among kids in a kindergarten. Tools used in this study included Told-P:3, Raven's standard progressive matrices, Expressive One-word Picture Vocabulary Test, Renfrew Action Picture Test, sentence completion subtest from the Wechsler Preschool and Primary Scale of Intelligence (WPPSI), and the Serial Reaction Time task (SRT). To analyze the data, we used the Kolmogorov-Smirnov test. The Pearson Correlation Coefficient was also used to measure the dependence between the variables. This study provides evidence of abnormal procedural memory functioning in children with SLI based on the PDH; however there is no correlation between grammar deficits and abnormal procedural memory in either the SLI (r-value = -0.52, sig. = 0.14) or the control group (r-value = 0.73, sig. =0.73). The results provide mixed support for the PDH. Thus, additional research is required to substantiate the results observed in this study.