Perceptual processing and search efficiency of young and older adults in a simple-feature search task: a staircase approach.

The reasons that visual search may sometimes be difficult, especially for older adults, remain important research issues. This study investigated (a) whether age-related differences can occur in simple-feature search, (b) if so, whether slowing adequately accounts for these differences, (c) whether other perceptual/cognitive factors are involved, and (d) the role of perceptual strategies. The authors tested 15 young adults (ages 18-30) and 15 older adults (ages 65-78). The target was a red disc presented among red diamonds in an array of 16 or 36 items. The forced-choice staircase procedure emphasized perceptual processing while deemphasizing decision-making and psychomotor processing. Although perceptual slowing may affect older adults' search performance, the perceptual slowing model is not simple, and other perceptual/cognitive factors, such as spatial resolution and distractibility, also are implicated. Moreover, perceptual strategies involving perceptual grouping or suppression of distractors play a key role in explaining why search efficiency is actually better for the larger set size.