In this one-year R56 project, the investigators will design a mini-longitudinal project to test how children's linguistic statistical learning predicts their growth in spoken and written language in three months. The investigators predict that weaker linguistic statistical learning underlies the exacerbation of language and literacy delay in children with ASD. In this project, the investigators will gamify an existing study protocol, which has led to promising discoveries motivating the original R01 proposal. With an enriched platform, the investigators expect a low attrition rate (\<10%) and few missing data (\>90% task completion rate) in this longitudinal sample of six-year-olds both with and without ASD, matched on age and sex ratio. This project will lead to critical feasibility and preliminary data to support the key hypotheses of all three aims. Due to a shortened timeline, the investigators plan to recruit 25 children per group, sampled from a diverse population, to ensure the team's capacity for a three-month follow-up session before the end of a school year.

Aim 1: Establish the longitudinal relationships between SL and language/literacy development in both TD and ASD. In this aim, the investigators will evaluate the role of SL in both concurrent and the growth of language/literacy skills assessed in three months during the school year. The investigators expect that linguistic SL (embedded pattern learning of syllables and letters) is associated with concurrent language and literacy skills and will prove to be crucial predictors of growth in language and literacy skills in both groups. Given the small sample size in this one-year project, the investigators will build prediction models both across the two groups and within each group. Sex, concurrent language and reading skills, and nonverbal IQ will be included as key covariables.

Aim 2: Determine the longitudinal relationships between neural bases of SL and developing language networks in the brains of children with ASD. In this aim, the investigators will test whether altered brain functions during linguistic SL are related to poorly functioning language networks (language comprehension and phonological working memory), defined within each individual child. The investigators will also examine whether neural bases of linguistic SL predict future language and literacy development in children with ASD. Participants from Aim 1 will complete linguistic SL tasks and two well-validated language tasks in the fMRI scanner at Time 1. The investigators expect to find reduced engagement of language networks during SL in children with ASD and to provide a neurobiological explanation for the cascading effect impaired linguistic SL casts on future language development.

Aim 3: Test whether linguistic SL is a proxy for children's sensitivity to real-world language statistics. The investigators ask whether the specific weakness in linguistic SL in ASD generalizes to real-world language statistics using serial recall tasks, a well-validated instrument for individuals' sensitivity to native-language statistical patterns. The same participants in the previous aims will complete a phonological and an orthographic serial recall task containing both high- and low-frequency English bigrams/trigrams at Time 1 and Time 2. The investigators predict that these tasks will be associated with children's linguistic SL performance in Aim 1 and children's linguistic SL at earlier times will predict the future growth of sensitivity to natural language statistics. These findings will establish the critical link between linguistic SL and children's natural language skills.