Development of visual attention: a stereoscopic view.

Five-year-olds, 8-year-olds, and adults (20 each) tachistoscopically viewed random-dot stereograms containing either uniform depth or an elevated disk whose perimeter fell 1.5 degrees, 2.5 degrees, or 4 degrees beyond fixation. When subjects were forewarned as to the size of the disk to look for (precued trials), signal detection improved (d' increased) for all three groups, and 5-year-olds improved the most. Without forewarning (self-cued trials), the 5-year-olds performed more poorly than the other two groups, which performed alike. Although young children are able to allocate their visual attention selectively, they do not appear to deploy it as quickly or as effectively as their elders when the focus of attention is theirs to choose.