Segregating is essential for and acting the objects in one's figures from grounds effectively perceiving upon environment. Reaching for and grasping objects, navigating a cluttered environment, and accurately perceiving how objects are arranged in depth all depend on the perception of some regions as figure and others as background. Therefore, figure-ground (FG) segregation has implications for normal cognitive and perceptual development in infancy. Despite the importance of FG segregation for infants' cognitive development, no research has directly investigated infants' sensitivity to cues to FG assignment. This is one goal of the proposed work. Cues to FG assignment are perceptual regularities that infants can learn as they perceive and act on the visual world. Another goal of the proposed work is to understand how motor achievements provides new opportunities for infants to learn such regularities. Preliminary findings indicate a relation between the emergence of self-sitting, a motor achievement that has consequences for infants' skilled reaching for objects, and infants' use of symmetry as a cue to FG segregation. The proposed project will further explore this relation by (1) refining the assessment and classification of infants' sitting abilities (Experiment 1), (2) evaluating the relation between self-sitting abilities and infants' use of a different cue to, FG segregation, lower region (Experiment 2), (3) developing a new procedure to directly test the relation between reaching and infants' FG segregation (Experiment 3), and (4) longitudinally assessing both selfsitting and FG segregation abilities to determine the developmental time courses of these two abilities (Experiment 4). The proposed experiments, therefore, will add significantly to our understanding of an aspect of infants' visual perception that has consequences for their abilities to learn about and effectively interact with the environment, and these experiments will provide a deep understanding in the mechanisms that underlie developmental changes in this aspect of infants' visual perception.