Retrieval-Based Word Learning in Developmental Language Disorder During Book Reading

Children with developmental language disorder (DLD; also referred to as specific language impairment) experience a significant deficit in language ability that is longstanding and harmful to the children's academic, social, and eventual economic well-being. Word learning is one of the principal weaknesses in these children. This project focuses on the word learning abilities of four- and five-year-old children with DLD. The goal of the project is to build on the investigators' previous work to determine whether, as has been found thus far, special benefits accrue when these children must frequently recall newly introduced words during the course of learning. In this study, the investigators seek to replicate the advantage that repeated retrieval holds over simple exposure to the words and to demonstrate an increase in children's absolute levels of learning by implementing retrieval practice in the context of a story book.

Developmental Language Disorder (DLD) affects language learning in an estimated 7% of children. Although much of the research literature has emphasized difficulties learning grammar, children with DLD also have major deficits in vocabulary. In recent work, the investigators have been examining the benefit of retrieval practice to enhance word learning and retention in preschoolers with DLD. The rationale behind this work is grounded in the growing literature in the field of cognitive psychology which shows that repeated practice in retrieving information results in greater long-term retention than continuous study of that information without opportunities for retrieval. In addition, retrieval practice that occurs after a delay-or "spacing" between study of a word and subsequent recall attempts-can lead to stronger effects. The investigators have explored the benefits of retrieval practice for preschoolers with DLD and with typical language development (TD), showing that recall and retention for novel words (nouns, adjectives, verbs) were greater when learned using repeated spaced retrieval (RSR) than when learned using repeated study only. Despite benefitting from RSR, children with DLD still showed lower levels of recall than children with TD. In the current study, the investigators aim to increase accuracy levels by embedding the same words and retrieval schedules used in earlier studies into story contexts. Artist-illustrated stories incorporate illustrations of the unfamiliar plants and animals that served as referents of novel nouns in an earlier study. Sixteen children with DLD will be recruited for this study along with 16 children with TD matched on chronological age. Using a within-subjects design, children will learn eight novel nouns, four embedded in each story. Along with each word form, children will learn a "meaning", that is, an additional piece of semantic information about the referent. For words in the RSR condition, each novel word and meaning, paired with its referent, will be presented as part of the story. Immediately after hearing it, children will be asked to recall both form and meaning, and then will hear those repeated. All subsequent retrieval trials will occur after three other words have intervened since the last time the word appeared in a study trial. Novel words assigned to the comparison condition will simply be heard paired with their referent during the story at the same frequency as words in the RSR condition. Children will not be asked to recall the words in the comparison condition during the learning period. Stories will be presented twice on each of the learning days. As written, the stories are a reasonable length and pace, but by repeating the story, children will hear the words the same number of times overall as in the investigator's previous studies, allowing evaluation of the benefits of the story format. Recall of the word forms and meanings will be tested after the story book reading on the second day and one week later. One week later, the recall test will be re-administered and children will complete a three-alternative recognition test. The investigators hypothesize that children will show greater recall for word forms in the RSR condition than those in the repeated study condition; past studies have not consistently shown an advantage for recall of "meaning" or for recognition. It is also expected that children with TD will remember more words overall than children with DLD. To the degree that the story format is more engaging for children, overall recall will be enhanced for both groups. Assuming that the results are replicated, it is hoped that the children's book reading format will prove amenable for use by teachers and speech-language pathologists who work with children with DLD.

Each child will learn 8 novel nouns referring to unfamiliar plants and animals ("nepp") and a related "meaning" ("a nepp likes rain"). Four nouns will be learned in a "spaced retrieval" practice condition; four will be learned in a "study only" practice condition. In the spaced retrieval condition, children will hear the information (word form and meaning) and be asked to immediately retrieve it. Thereafter, they will be asked to retrieve it after hearing 3 intervening word form/meanings. Each retrieval bid will be followed by feedback in the form of hearing the information again. In the "study only" practice condition, children will simply hear the information (word form and meaning).

Learning sessions: Children will practice novel nouns in the context of a story book on Day 1. They will learn 4 words in each of the two conditions. "Study only" condition: they will simply hear the information (word & meaning) as part of the story. "Spaced retrieval" condition: they will initially hear the information and be asked to retrieve it. Thereafter, they will be asked to retrieve it after hearing 3 intervening words. After each retrieval attempt, they will hear the target information again. In the "study only" practice condition, children will simply continue to hear the information. This practice schedule is repeated the next day (Day 2) using the same story book. Testing sessions: 5 minutes after the learning session on Day 2, the child is asked to recall each word and meaning twice. One week after Day 1, this recall test is completed again. The child will also complete a recognition test: the child will hear a novel noun and point to its referent in an array of 3.

Upon hearing a novel word, the child is asked to indicate (by pointing) which picture among 4 options is referred to.

Upon hearing a word, the child is asked to indicate (by pointing) which picture among 4 options is referred to.

Primary care-giver provides information regarding highest academic degree attained, converted to years of education

Inclusion Criteria: a significant deficit in language ability (language test score below cutoff for best sensitivity/specificity) or documented age-appropriate language ability. normal hearing no evidence of neurological damage or disease scores on tests of nonverbal intelligence above the intellectual disability range not within Autistic range on Autism screening test native English speaker (can be bilingual) Exclusion Criteria: failed hearing screening known neurological damage or disease scores on tests of nonverbal intelligence below the intellectual disability range (standard score less than 75) autism spectrum disorder non-native English speaker

Data will become available after the results are published or within 12 months from the primary completion date (i.e., the date of final data collection for the primary outcome measure).