Core knowledge and the emergence of symbols: The case of maps

Abstract

Map reading is unique to humans but present in people of diverse cultures, at ages as young as 4 years. Here we explore the nature and sources of this ability, asking both what geometric information young children use in maps and what non-symbolic systems are associated with their map-reading performance. Four-year-old children were given two tests of map-based navigation (placing an object within a small 3D surface layout at a position indicated on a 2D map), one focused on distance relations and the other on angle relations. Children also were given two non-symbolic tasks, testing their use of geometry for navigation (a reorientation task) and for visual form analysis (a deviant-detection task). Although children successfully performed both map tasks, their performance on the two map tasks was uncorrelated, providing evidence for distinct abilities to represent distance and angle on 2D maps of 3D surface layouts. In contrast, performance on each map task was associated with performance on one of the two non-symbolic tasks: map-based navigation by distance correlated with sensitivity to the shape of the environment in the reorientation task, whereas map-based navigation by angle correlated with sensitivity to the shapes of 2D forms and patterns in the deviant detection task. These findings suggest links between one uniquely human, emerging symbolic ability, geometric map use, and two core systems of geometry.

Figure 1

The displays used in the experiment. (a) Schematic depiction of the apparatus and maps used in the side condition (left) and corner condition (right) of the map task. For each condition, the upper figure presents an overhead view of the enclosure and one of the three positions of the experimenter presenting the map to children (arrow); the lower figure presents the three maps used for that condition. Each map was presented at the depicted orientation, relative to the child, and therefore at a different test position and orientation relative to the enclosure. (b)The reorientation apparatus, viewed from above, used for the most difficult (left), moderately difficult (center), and easiest (right) reorientation tests. C indicates one target location; C and R indicate the geometrically correct searches for that target location. (c) The displays used for practice (top) and to test sensitivity to each of four different geometrical properties in the test of visual form analysis: distance and length (top left), asymmetry (top right), angle (bottom left), and parallelism/alignment (bottom right).

Figure 2

Children’s performance on the tests of map interpretation, reorientation and form analysis. (a) Percent correct target placements for the two map-based navigation tasks. (b) Percent of total search trials that were directed either to the correct corner or to the geometrically equivalent opposite corner on in each of the three arrays used in the reorientation task. Error bars indicate ±1 standard error of the averaged percent of both corners. (c) Percent correct choices for each geometrical property tested on the visual form analysis task. Asterisks indicate above-chance performance (one-sampled t tests, 2-tailed).