9600724 BHATT What information do infants extract from their environments and how does this information affect their subsequent behavior? This research will explore this question by examining basic mechanisms of object perception, memory, and developmental changes in the interface between perception and memory in 3- and 6-month-olds. One prominent class of models of object perception assumes that a limited set of fundamental features underlies all of object perception and that, in adults, information about such individual features is registered in parallel across the visual field during the initial stages of object perception. Evidence for these propositions comes from the extensive study of pop-out effects in adults. The term "pop-out" refers to the phenomenon that an object in a visual display that differs from surrounding objects in terms of individual features is perceived effortlessly. A series of studies will examine whether infants exhibit adult-like pop-out effects, the conditions that engender pop-out effects in infancy, and whether the features viewed as building blocks of object recognition in adults also play a similar role in infancy. In addition to the detection of features, the perception of relations among features is also critical for object recognition. A set of studies will examine the stimulus conditions that facilitate the encoding and memory of relational information in infancy. Also, prior research has revealed that, although infants do remember both features and feature relations, they forget feature relations sooner than the individual features that comprise these relations. A series of studies will analyze possible memory retrieval and interference mechanisms that underlie this dissociation. In addition to the physical aspects of stimuli, object recognition is also mediated by "top-down" processes such as expectancies and the ability to selectively inhibit responding to stimuli. A final set of studies will examine devel opmental changes during the first half year of life in these processes. This research will contribute to the generation of a comprehensive model of early perceptual and cognitive development in normal infants, against which comparisons can be made to describe, analyze, and mitigate various disorders, such as attention deficit disorder and hyperactivity. Exceptional education activities will include development of audio-visual teaching materials and lab manuals to enhance both research methods and survey courses in developmental psychology, and special activities designed to provide minority high school and undergraduate students the opportunity to participate in research projects. ***
