Directed Language as a Useful Predictor of Speech Processing Efficiency and Vocabulary Development in Preterm Infants

University Of Tennessee Knoxville, Knoxville TN

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Abstract

ABSTRACT In utero, organized and predetermined patterns of auditory structural and neural pathway development set the stage for early language acquisition.15 The very low birth weight (VLBW) preterm infant, born at 24-26 weeks of gestation is at a critical stage of structural and functional auditory development in a suboptimal environment.3, 15 The Neonatal Intensive Care Unit (NICU), vastly different from the protected uterine environment is full of high pitched alarms, harsh mechanical sounds from lifesaving respiratory equipment positioned in close proximity to developing auditory structures.8 Environmental NICU conditions have been correlated with increased stress and systemic inflammation resulting in negative neurodevelopmental outcomes.3, 21 Identified factors associated with speech and language delay or impairment in the VLBW preterm population include low birth weight, low gestational age, socio-economic risk factors, prolonged hospitalization and increased illness.4, 9 Yet, few interventions directed toward the VLBW preterm infant while hospitalized in the NICU have shown neurodevelopmental improvements especially in the area of language acquisition. Thus, one of the aims of this study is to explore whether measures of neonatal stress is affected by bouts of directed language in the VLBW preterm infant. Early and frequent directed speech may be useful to mitigate some of the modifiable short and longterm negative effects of preterm birth, yet evidence for this link is missing. Through longitudinal design, language input will be recorded at 4-time intervals during NICU hospitalization and at 4 time intervals following hospital discharge using the Language ENvironment Analysis (LENA). Language development will be measured at 12 and 18 months in the Infant Language and Perceptual Learning Lab. Our goals are to determine if the timing and frequency of direct language exposure during critical periods of auditory development are associated with (1) improved biophysical markers of neonatal stress during hospitalization, (2) continued language exposure in the home, and (3) improved speech processing efficiency and vocabulary size in this at-risk population. This information will provide new scientific knowledge to support interventions including early and frequent human voice in the preterm population as a method to improve neurodevelopmental outcomes. Graduate and undergraduate students in Nursing and Psychology are critical to the implementation of this project. Nursing students will have the opportunity to spend a semester interning in a language development lab, and Psychology students in the NICU environment. Thus, in addition to making significant contributions to science and informing clinical practice, this interdisciplinary opportunity will enrich research training of Nursing and Psychology students.