Divided attention and visual search for simple versus complex features.

Under what search conditions does attention affect perceptual processes, resulting in capacity limitations, rather than affecting noisy decision-making processes? Does parallel or serial processing cause the capacity limitations? To address these issues, we varied stimulus complexity, set size, and whether distractors were mirror images of the target. Both target detection and localization produced similar patterns of results. Capacity limitations only occurred for complex stimuli used in within-object conjunction searches.

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).