Evaluates preschoolers' ability to distinguish left-right mirror-images of objects on a memory task and ability to name rows of objects on a page in a consistent lateral direction. Abilities were assessed first without specific instructions on the relevance of left-right information and then with instructions. (Author/AS)

Preschool, second-, and sixth-grade children performed developmentally gradated, easy and difficult visual discrimination tasks in a quiet room or with one of two levels of extraneous auditory stimulation. Subjects' errors, response latencies, and glances away from the task were recorded. (Author/RH)