Wolfert, Katherine E.. Factors influencing developmental plasticity: how interactive auditory experience shapes sensory processing and language development. Retrieved from https://doi.org/doi:10.7282/t3-dtcs-1f45
DescriptionThe infant brain demonstrates remarkable plasticity during the first year of life, changing its structure and function in response to environmental inputs. Developing neural circuits become tuned to efficiently respond to frequently-encountered stimuli, establishing a foundation for complex cognitive functions such as language. But not all early experiences induce lasting changes, we continue to learn about the specific conditions required to induce plasticity. In this thesis, we explored how early auditory experiences within an interactive context affect the infant brain across multiple domains, including auditory processing, visual processing, and language development. We first examined the factors contributing to individual differences in infant behavior as they participated in an interactive auditory experience, finding that electrophysiological markers indicative of more mature acoustic change detection at baseline predicted better performance during learning sessions. Behavior was also influenced by non-auditory factors, including gross motor skills, maternal age, and the quality of parent-child interactions. We then investigated the role of timing in early plasticity, comparing the effects of interactive auditory experience in younger and older infants. Although markers of auditory processing tended to improve as infants matured, auditory experience had less impact at older ages, perhaps reflecting the influence of domain-general factors on task performance. Finally, we examined parallels between processing in the auditory and visual systems, observing that auditory learning did not transfer to the visual modality but there were associations between auditory and visual development and concurrent language skills. These findings advance our understanding of how infants process brief, rapidly-changing stimuli across sensory domains, a skill thought to be important for language development, and how early experiences enhance this ability. There are also implications for identification and early intervention for language-based developmental disorders, furthering efforts to identify biomarkers of infant development and develop methods to support the development of all infants.