The Short-term Verbal Memory Endophenotype for Developmental Language Disorder Language Disorder

The goal of this clinical trial is to determine how memory and attention affect the ability of children with developmental language disorder (DLD) to learn and use new vocabulary. Aims 1-3 include children with DLD and healthy children with typical language development. The general hypothesis is that the memory and attention challenges that characterize DLD, but not healthy development, affect the robustness of word learning. Aim 4 includes healthy children only to simulate the cascading effects of weak word learning on the broader linguistic system. The main questions this clinical trial aims to answer are: What is the role of linguistic long-term memory in children's ability to hold new verbal information in short-term memory? What is the role of attention in children 's ability to hold new verbal information in short-term memory? What are the cascading effects of short-term verbal memory problems on the integrity of the language system? In Aim 1a, researchers will compare syllable repetitions when those syllables do or do not have English-like prosody and do or do not have meaning to see if knowledge of prosody and word meaning supports accurate short-term memory. In Aim 1b, researchers will compare the repetition of adjectives and nouns when those words do or do not have English-like grammar (i.e., when they are presented as adjective + noun rather than noun + adjective) to see if knowledge of word order supports accurate short-term memory. In Aim 2, researchers will compare the syllable repetitions when those syllables are presented with or without attention cues and with or without a delay of 500msec between presentation and response to see if attention facilitates accurate short-term memory. The delay condition is intended to increase load on short-term memory. In Aim 3, all measures are observational. The researchers will assess the child's long-term memory of language, attention skills, and verbal short-term memory to see if children with DLD but good attention skills are able to perform well on short-term memory tasks. In Aim 4, researchers will compare the ability of children to comprehend newly learned words that are taught via active retrieval or passive study. Active retrieval yields more robust learning, and passive study yields weaker learning. The goal is to compare how well children use those newly learned words to recall semantic category information (e.g., was it a bug or a bird) and comprehend sentences to see if the weak word learning has cascading impacts beyond learning the word itself.