Infants' ability to mentally track the orientation of an object during a hidden rotation was investigated (N = 28 in each experiment). A toy on a turntable was fully covered and then rotated 90°. When revealed, the toy had turned with the turntable (probable event), remained at its starting orientation (improbable event in Experiment 1), or…

How is number-concept acquisition related to overall language development? Experiments 1 and 2 measured number-word knowledge and general vocabulary in a total of 59 children, ages 30-60 months. A strong correlation was found between number-word knowledge and vocabulary, independent of the child's age, contrary to previous results (D. Ansari et…

From birth, infants detect associations between the locations of static visual objects and sounds they emit, but there is limited evidence regarding their sensitivity to the dynamic equivalent when a sound-emitting object moves. In 4 experiments involving thirty-six 2-month-olds, forty-eight 5-month-olds, and forty-eight 8-month-olds, we…

Investigated 5-month-olds' perception of an object whose center was occluded and whose ends were visible only in succession. Found that infants perceived the object as one connected whole when the ends underwent common motion but not when the ends were stationary. Results suggest that infants perceive object unity but not object form. (Author/BC)

A total of 20 infants either five or seven months of age viewed computer-generated random-lot displays in which accretion and deletion of texture provided the only information for contours. Infants of both age groups showed significant preferences to reach for the apparently nearer regions in the displays. (Author/RH)

Preschoolers placed stickers on maps to show locations of objects currently in view. Vantage point (eye-level versus raised), map form (plan versus oblique), and item type (floor versus furniture location) were varied. Results showed that using an oblique map first aided subsequent performance on a plan map. Subjects performed worse on floor…

The perceived spatiotemporal continuity of objects depends on the way they appear and disappear as they move in the spatial layout. This study investigated whether infants' predictive tracking of a briefly occluded object is sensitive to the manner by which the object disappears and reappears. Five-, 7-, and 9-month-old infants were shown a ball…

In three experiments, three- and four-year olds were asked to map relative size from one array of objects to another, map relative size to relative proportion, and map relative size to a variety of perceptual dimensions. Children were able to make relational mappings based on size when spatial positions and concrete representations of size of…

Four experiments investigated three- and four-year-old children's knowledge of projective size-distance and projective shape-orientation relationships. Results indicated that preschool children's understanding of these relationships seems at least partly cognitive rather than wholly perceptive, providing further evidence for the acquisition of…

Examined development of infants' relational coding in spatial orientation problems. Found that 6-month-olds performed poorly in a peekaboo task in which they had to turn to a target after displacement to a novel position and direction. Twelve- month-olds solved the tasks whether or not target was located between two landmarks; 8.5-month-olds…

In Experiment I, 24 preschoolers were tested on left-right, vertical-horizontal, and mirror-image oblique discriminations under essentially context-free conditions. Experiment II contrasted children's performance under context-free conditions with their ability to discriminate orientation in the presence of external visual cues. (RH)

Two experiments found that (1) by age 8 months infants perceived that leaning extends their effective reaching space to grasp objects; (2) by 10 months they perceived the effective limits of leaning and reaching; and (3) by 12 months they began to perceive how this space may be extended by a mechanical aid. (MDM)

In two experiments, preschool children and adults were asked to judge which way an equilateral triangle was pointing under several contextual conditions. Results indicated that children and adults attended to both global and local levels of a pattern. (BC)

Investigated 4-6 year olds' ability to compare the distances covered by a direct and an indirect route to a location. Although many children believed that both routes covered the same distance, about 40% of the four year olds could explain why the direct route was shorter. (MDM)

Two studies of development of spatial representation with two dimensions found that children as young as five years use the same two independent dimensions in fine-grained spatial coding of location in a circle as adults use--radius and angle. The adult pattern, where angle as well as radius is coded hierarchically, emerges by nine years. (HTH)