Infant-directed (ID) speech is an important source of stimulation for young infants, but depressed mothers produce ID speech that is perceptually and affectively flat (1,2). Four-month-old infants of depressed mothers exhibit associative learning deficits in a conditioned-attention paradigm, in which a brief segment of their own mother's ID speech signals the appearance of a smiling face (3). Six- to 13-month-old infants of chroncially depressed mothers, unlike 4-month-olds, further fail to learn in response to """"""""high-quality"""""""" ID speech produced by an unfamiliar non-depressed mother (4). However, these older infants exhibit better- than-normal learning in response to male ID speech (4). The proposed research has three Specific Aims.
Specific Aim 1 is to investigate the development of the generalized learning deficit in response to maternal ID speech by giving individual infants of depressed and non-depressed mothers associative learning tests with """"""""high-quality"""""""" maternal and paternal ID speech at both 4 and 12 months of age.
Specific Aim 2 is to examine the relationship between infant learning in response to the infant's own depressed and/or non-depressed mother's and father's ID speech, and whether the quality of parent-infant interaction and attachment relationships mediate the effects of ID speech on infant learning.
Specific Aim 3 is to assess 12-month-old infants whose mothers and fathers are both chronically depressed for their responses to """"""""high-quality"""""""" ID speech produced by unfamiliar non-depressed mothers and fathers, to determine if these infants exhibit the broadest learning deficits. These studies are important because they permit a rigorous analysis of the development of learning deficits in infants of chronically depressed mothers, and point to a plausible mechanism through which initially able learners develop generalized learning deficits. These experiments promise to lay the foundation for future studies aimed at preventing learning problems in infants of depressed mothers.
