Convergence and Divergence in Representational Systems: Emergent Place Learning and Language in Toddlers

Convergence and Divergence in Representational Systems: Emergent Place Learning and Language in Toddlers Frances Balcomb (FBalcomb@Temple.Edu) Department of Psychology, Weiss Hall, 1701 N. 13 th Street Philadelphia, PA 19122 USA Nora Newcombe (Newcombe@Temple.Edu) Department of Psychology, Weiss Hall, 1701 N. 13 th Street Philadelphia, PA 19122 USA Katrina Ferrara (Katrina.Ferrara@Temple.Edu) Department of Psychology, Weiss Hall, 1701 N. 13 th Street Philadelphia, PA 19122 USA Abstract are different neurological underpinnings, with the caudate underlying egocentric strategies and the hippocampus underlying place learning (Compton, 2004; Iaria et al, 2003). However, the way in which they are combined is only beginning to be understood. This is an especially interesting question in young children who begin navigating when both their bodies and minds are changing rapidly, allowing them unprecedented access to new ways of physically and mentally interacting with the world. A primary goal of this study was to use an adapted Morris water maze to explore the nature of children’s search strategies as place learning emerges. Developmentally, egocentric strategies appear first, followed by landmark use (Acredolo & Evans, 1980; Cornell & Heth, 1979). Even in early development young children, like adults, can use a dynamic combination of strategies. For example, 6-month-olds rely on egocentric strategies to look for a previously viewed stimulus after changing perspective 180 degrees, while 9- and 11- month-olds use a mix of ego and allocentric responses. However, when the salience of the target is increased, all age groups shift to using more allocentric strategies (Acredolo & Evans, 1980), suggesting that even as spatial abilities emerge they are dynamically incorporated with other spatial strategies. Significant changes in spatial representation occur at 20-24 months, including the emergence of place learning (Newcombe, Huttenlocher, Drummey, & Wiley, 1998; Sluzenski, Newcombe, & Satlow, 2004). For example, while 18 to 22-month-olds are able to use dead reckoning to search for a hidden object after a position change, only children older than 22 months can use external features to increase the accuracy of their searches (Sluzenski et al., 2004). From this research it is clear that various search strategies come online early, with place learning emerging at about 24 months of age. What is missing in the developmental picture is a research methodology that can provide descriptive data about children’s search strategies as place Language and spatial reasoning are two primary abstract representational systems in humans. Language acquisition has been much studied, while the ontogeny of spatial navigation is comparatively less well understood, as is the relationship between early language and space. This study explored emergent place learning and language in 16- to 24-month-old children using a spatial task adapted from the Morris water maze, and the MacArthur Communicative Development Inventory. Children were placed in a circular enclosure and a puzzle was hidden under the floor at one location. Before each trial children were disoriented and placed in the maze from a different starting position. Their search strategies and success at finding the puzzle were coded. Older children demonstrated more spatial searching and more goal-finding success, as well as greater overall expressive vocabulary. Place learning and expressive language both significantly correlated with age, but place learning and language did not correlate with each other once age was partialled, with one crucial exception: a theoretically-predicted correlation between prepositions and goal localization. Keywords: Place learning; spatial language; spatial development Introduction People navigate the world every day, utilizing various spatial strategies. There are two systems of such strategies; egocentric (involving self-referencing), and allocentric (using viewer-independent referencing). Allocentric strategies include landmark use (identifying features at or immediately near a goal) and place learning (triangulating a location using relationships between distal features). Evidence suggests that adults use both ego and allocentric strategies dynamically, preferentially weighting each according to the task and context (Iaria, Petrides, Dagher, Pike & Bohbot, 2003), and that there