Unlike children's early ability to navigate by continuous boundaries, their ability to extract geometric information from an array of objects emerges gradually over childhood. To investigate children's developing representation of object arrays for navigation and its relation to their mental representation of the global spatial layout,…

Spatial scaling is an important prerequisite for many spatial tasks and involves an understanding of how distances in different-sized spaces correspond. Previous studies have found evidence for such an understanding in preschoolers; however, the mental processes involved remain unclear. In the present study, we investigated whether children and…

Three experiments explored determinants of two-year olds' perseverative errors in a search task. Found that active search, even in the absence of observation, produced perseveration on post-switch trails, but mere observation did not. Results indicated that active search is required to elicit perseveration, which points to failures of response…

Provided 2- and 2.5-year-olds with partial visual information about a ball's path as it moved toward a hiding place. Found that both age groups were equally proficient at tracking the ball as it rolled behind a transparent screen with 4 opaque doors, but 2.5-year-olds were more likely to reach to the correct door when asked to find the ball.…

Investigated 3-year-olds' understanding of the appearance-reality distinction using verbal response and nonverbal response paradigms in 4 experiments. Found that about 30 percent of children were correct in verbal paradigm; over 90 percent of same children were correct in nonverbal paradigm. Participating in the verbal paradigm impeded children's…

Four experiments examined 8- to 12-month olds on search and nonsearch A not B tasks, a one-location task, and control tasks. Results indicated memory for where object was hidden and expectations of where it should be found. The effect occurred at delays at which infants made the A not B error when searching, and at a longer 15-second delay.…