How infant-directed speech organizes the attentional state of infants - PROJECT SUMMARY/ABSTRACT
Social interactions with mature social partners scaffold and support far-reaching developmental outcomes
including vocabulary development, school achievement, self-control, and executive functioning. Despite being
critical to the healthy and successful development of infants, the mechanisms by which mature social partners
can influence development is not clear. An emerging literature suggests caregivers influence infant development
by directly influencing the infant’s internal state, including changes in autonomic activity. The proposed research
connects the vocalizations of mature social partners with infant autonomic activity and sustained attention, a
cognitive milestone highly predictive of individual differences in infant visual attention, self-control, language, and
later school achievement. The proposed research is focused on identifying the acoustic features of the social
partner’s voice and how those properties influence autonomic state and sustained visual attention to objects in
12- to 24-month old infants, ages when individual differences emerge with predictive consequences. The
overarching hypothesis is that the acoustic properties of caregiver voice act on the autonomic state of the infant,
supporting sustained visual attention. As such, the proposed studies measure multiple components of infant
behavior: eye gaze, body movement, and heart rate, by using methodologies such as head-mounted eye-
tracking and an in-house built wireless vest equipped with state-of-the-art sensors in addition to the voice of the
mature social partners. Specific Aim 1 (K99) uses an experimental paradigm to manipulate, identify, and link
specific acoustic features of heard vocalizations to the autonomic state of infants and to looking duration during
active visual exploration of objects in naturalistic play. Specific Aim 2 (R00) will longitudinally measure the
development of individual differences in visual attention and object name learning in relation to caregiver
vocalizations and their effect on autonomic state. Analyses will examine individual developmental trajectories
and the emergence of individual differences in sustained visual attention and name learning in relation to the
effects of caregiver vocalization on autonomic state. The proposed research will advance the field by linking the
role of in-the-moment measures of caregiver vocalization, to infant gaze and infant autonomic activity to long-
term developmental outcomes such as self-regulated attention and learning, providing a potential new path to
determining targets for intervention for at-risk infants. In pursuing these research objectives, the applicant will
complete a tailored set of scientific and professional development activities that go beyond the applicant’s current
training. This will include training in the collection and analysis of large, multimodal, longitudinal data, training in
graph theoretic network analysis, and advanced training in the measurement and analysis of sustained attention.
Coupled with the applicant’s previous training, this skillset will prepare the applicant to launch an independent
research career that is well-grounded in theory, multi-faceted in methodology, interdisciplinary, and with
translational implications.
