Changing priority maps in 12- to 18-month-olds: an emerging role for object properties

Abstract

Everyday action in the world requires the coordination of "where," "when," and "how" with "what." In late infancy, there appear to be changes in how these different streams of information are integrated into the sequential organization of action. An experiment with 12-, 15-, and 18-month-olds was conducted in order to determine the influence of object properties and locations on the sequential selection of targets for reaching. The results reveal a developmental trend from reach decisions' being influenced only by the spatial layout of locations to the overall pattern of reaching's being influenced by the global configuration of object properties to object properties' influencing the sequential decision of what to reach to next. This trend is a new finding regarding the development of goal-directed action in late infancy.

Figure 1

(Top panel) Schematic of the spatial layout of the boards. (Bottom panel) The configurations of objects for Array 1 (left) and Array 2 (right).

Figure 2

(Upper panel) Overall mean frequency of reaches per array to each location, except for Location CB (M = 1.236, SD = 0.143). (Lower panel) Means for the 12-, 15- and 18-month-olds. Bars represent standard errors.

Figure 3

Mean proportion of reaches to locations L1 and L2 when they contained majority and minority objects × age.

Figure 4

Mean proportion of transitions from the center location to locations L1 and L2 when they contained minority (property match to center) and majority objects × age.