9631680 NEWCOMBE Spatial competence is a fundamental adaptive capability for all mobile organisms. Human adults can use distance and direction information to code location, both with respect to the self and with respect to external landmarks. Their spatial coding is hierarchical, i.e., existing at various nested levels of resolution. In addition, they can use symbolic spatial representations, most notably maps. This research will advance our understanding of how these aspects of spatial competence develop in human infancy and childhood. Previous studies have already shown that, by 16 months, children show hierarchical metric coding of spatial location, but that, at about 21 months, there is an abrupt increase in the use of external landmarks distant from the viewer in such coding, and that, over middle childhood, there are changes in the nature of the categories used in higher-level coding. Studies with infants will determine whether metric coding is present early in life, and if so, what referents are used in such coding, and what the resolution of the system is. Studies with toddlers will define whether the developmental changes in the use of distal landmarks are due to hippocampal maturation or to growing control of upright walking, and whether children of this age can remember the location of particular objects in particular locations when more than one is hidden at a time. Studies with school-age children will determine whether developmental changes in the nature of categories used in hierarchical coding underlie real-world changes in accuracy of spatial localization. Other studies with preschool and school-aged children will delineate how children use distance and direction information in map representations. Overall, this research program will develop further a model of the emergence of spatial competence. Understanding spatial development is an important theoretical goal in itself, but also has implications for such important societal iss ues as affording mobility to visually-impaired children and furthering the education of all children in spatial subjects such as geometry and geography. ***
