As the population of Spanish-English bilingual children in the United States steadily grows, the importance of accurately assessing and diagnosing developmental language disorder (DLD) has also grown. Understanding a child's underlying language learning system is critical in this process. Several studies have demonstrated the efficacy of nonword repetition (NWR) tasks in bilingual children across a wide range of development, however there is little information regarding guidelines for interpretation of NWR performance or analyzing error patterns. This study was conducted to address these gaps in the research. A sample of 26 Spanish-English bilingual school aged children (6;0-9;4) were administered English and Spanish NWR, recalling sentences, and narrative tasks. Total errors, as well as errors of omission and substitution were examined across tasks, languages, and language group (typically developing-TD and developmental language disorder- DLD). Descriptive statistics revealed that DLD children made a higher number of errors across language tasks in Spanish and English than their TD peers. Group membership predicted total errors in the Spanish NWR task while controlling for age and language proficiency. Language proficiency was not a significant predictor for any of the error types above and beyond group membership. Therefore, when age and language input/output were controlled for, language ability was best predictor of the number of errors. Additionally, results showed stronger correlations between Spanish across all three language tasks in TD children and in English across two language tasks in DLD children. According to the results of the current study, total errors is the only effective error measure of language ability. However, looking at error patterns across language and language group can be informative regarding bilingual children's language learning systems. Future research should be conducted to repeat the study with a larger sample size and investigate the difference in error patterns between languages in TD and DLD children.

To address the needs of the growing number of Spanish-English bilingual children in the United States, Nonword Repetition (NWR) tasks were created to reduce testing bias in the assessment and diagnosis of children with developmental language disorder (DLD). Several studies have shown promising results in the use of NWR tasks; however, fewer studies have addressed questions such as the use of different scoring methods or analyzing error patterns. Thus, this study was conducted to address these gaps in the research. An English and a Spanish NWR task were administered to 26 Spanish-English bilingual school aged children (6;0-9;4). Two different scoring methods (percent phoneme correct and whole word scoring) were compared for diagnostic accuracy and the types and frequency of errors were analyzed. Both scoring methods showed statistically significant differences between groups (participants with DLD and those with typically developing language). Whole word scoring in Spanish had the best diagnostic accuracy, according to sensitivity, specificity, and likelihood ratio measures. However, due to the small number of nonwords that any participant repeated correctly, this may not be a clinically practical scoring method. The Spanish NWR task was a better measure than the English NWR task in identifying children with DLD, suggesting that Spanish NWR could be used to assess DLD in bilingual children. Participants with DLD produced more consonant, vowel, substitution, and omission errors than those with typically developing language. There was no difference between groups for addition errors. Significantly more omission errors were made in Spanish, likely due to the longer nonwords. The longer nonwords may be key in distinguishing between typically developing children and those with DLD. These results have the potential to inform future clinical practices in selecting, scoring, and analyzing NWR tasks.

Short-term memory (STM) has demonstrated to be affected by serial order, involving the use of rhythm and entrainment to stimuli. However, less is known of the extent of this relationship and language learning, and the literature focuses on words rather than sentences. Moreover, the literature lacks an exploration of whether this relationship has a correlation with MMN responses. We had 30 participants (21 female) complete two sentence repetition tasks, a temporal rhythm accuracy task, and two temporal order judgment tasks. We also recorded the electroencephalograms (EEG) from 24 of the participants (17 female) while they listened to syllables differing by time of presentation and differing by consonant and vowel. We then correlated performance on these tasks to performance on a foreign-word learning (FWL) task. We hypothesized that the STM tasks would predict performance in the FWL task, and we explored whether temporal accuracy and word learning correlated with MMN responses to early stimuli. We found that only the foreign sentence repetition task significantly predicted performance in the FWL task. We also did not find any significant correlations with MMN responses and temporal accuracy and word learning abilities. Findings show that with previous exposure to a novel language, the prosodic pattern of the foreign language is stored temporarily in STM, which enhances learning of the foreign words. Further exploration is needed to understand the relationship of temporal order and language learning with cortical responses. / Thesis / Master of Science (MSc) / Spoken language is driven by rhythm and keeping track of this rhythm allows us to keep track of the order in which sounds in language are presented. Remembering the order of items requires the use of short-term memory. The better one is at repeating back the order of items, the better they are at learning new words. This thesis investigates the relationship between various short-term memory tasks (English nonword sentence repetition task, foreign sentence repetition task, temporal rhythm accuracy task, auditory judgment task, visual judgment task) and foreign-word learning. This thesis also explores whether there is a correlation between one’s brain responses to differing stimuli and a person’s ability to track the timing and order of items, as well as a person’s ability to learn new words. The results reveal that only the foreign sentence repetition task, using the same foreign language as the word learning task, significantly predicts one’s ability to accurately learn foreign words. The results did not show any significant interaction between one’s neural responses and rhythm or word learning. These results suggest that the ability to maintain the order of items in memory aids word learning, but further exploration is required with regards to non-verbal stimuli and neural responses. It is important to investigate individual differences in repetition tasks that require short-term memory, as this will aid in understanding normal language development and language acquisition.