Linguistic and metalinguistic characteristics of Persian-speaking children with autistic spectrum disorders: A systematic review.

Studies of ASD children have mainly focused on pragmatics, but research showed they have problems in other language dimensions. The present systematic review aims to analyze the literature related to linguistic and metalinguistic studies to determine linguistic characteristics and their correlation with reading and writing. After reviewing 43 articles founded, the studies were divided into four main categories: descriptive, comparative, linguistic, and finally nonlinguistic interventional studies. 42% of studies are descriptive, 14% were comparative, and 5% were about the effect of linguistic and metalinguistic training on reading and writing. Studies on the effect of other training on linguistic and metalinguistic skills were about 39% of the studies. They have deficiencies in different linguistic and metalinguistic skills, especially grammar. There were no studies investigating the relationship between linguistic and metalinguistic abilities. The relationship between language and reading skills has been neglected and only one study has examined the correlation between phonological awareness and reading skills. Thus, there is a serious gap in metalinguistic studies. However, it is necessary to study these relationships due to the change in the reading education system from a phonological to a lexical path in schools. The effect of nonlinguistic interventions has been studied more than linguistic ones.