Gwen E. Gustafson - US grants

The proposed research concerns the development of young infants' cries and the perception of cries by parents and nonparents. Previous research has demonstrated that infants' cries reflect the health status of the infant, and some authors have speculated that infants with particularly aversive cries may be more likely than other infants to be abused by their parents. The precise acoustic basis of the perception of cries as aversive has not yet been elucidated, however. Further, most prior studies have focused on neonatal pain cries as stimuli. The proposed research will examine instead infants' hunger and discomfort cries, which parents hear everyday, and will determine the role that several acoustic measures play in the perception of cries as aversive. In addition, the differentiation of the early "basic" cry into several different signals will be examined. The short- and long-term stability of acoustic characteristics of cries will be determined. Finally, behavioral responses to cries that differ in perceived aversiveness and in controllability will be measured. Four studies are proposed: The first will determine experimentally the acoustic basis of nonparents' perceptions of cries as aversive. Electronic manipulations of hunger cries will be used to determine how timing, intensity, and frequency contribute to the aversive quality of cries. The second study will generalize the findings of Study 1 to parents, measure the short-term stability of acoustic properties of cries, and relate parents' perceptions of the aversiveness of other infants' cries to the acoustic properties of their own infants' cries. The third study will determine long-term individual differences stability of the structural properties of cries. In addition, developmental changes in the acoustic properties of hunger cries will be measured, along with the differentiation of cries in different social/motivational contexts. The fourth study will explore the relations among perceived aversiveness of an infant's cries, soothability of the infant, and perceptions of infant difficultness. The dual focus of these studies on the structural and functional aspects of infant cries will yield a fuller understanding of the cry's role in early parent-infant adaptation.

The proposed research concerns the development of crying in human infants and the development of caregivers' responses to crying. Previous research has often focused on the cry's diagnostic value for newborns, but the proposed research will focus on the value of cry analysis of understanding social and communicative development throughout infancy. The project will help integrate research on infants' cries with theories of social, cognitive, and communicative development, as well as with psychobiological and social-transactional approaches to the study of behavioral development. The broad concerns are how cries affect the events of day-to-day social interactions, and what infants may acquire through participation in these interactions. Social interactions are central to theories of social, personality, and language development in infancy, and thus the proposed work has implications for the etiology of poor developmental outcomes, such as unusual delays in the acquisition of social and communicative skills, failure to thrive, and infant neglect and abuse. The broad goals will be addressed via study of: (1) the developmental relation of cries to other communicative behaviors of infants, such as looking and gesturing; (2) developmental changes in behaviors of mothers in response to their infants' cries; and (3) development changes in the acoustics of the spontaneous cries of normal infants (with particular emphasis on whether the acoustic properties of early, reactive crying may form the basis of sound-meaning correspondence in older infants' sometimes voluntary cries). Two studies are proposed: Study 1 will involve detailed longitudinal analyses of the cry's relation to other communicative behaviors and of the responses of mothers to their infants' cries. Forty- eight infants will be video- and audiotaped in their homes at the ages of 2, 4, 6, 8, 10, 12, 15, and 18 months. Study 2 will involve acoustic analyses of cries according to their communicative functions (e.g., requests, protests). The audiorecordings from Study 1 will be the source of cries for Study 2, and acoustic differences related to age as well as to cry function will be examined.