Abstract
In a comparative visual search experiment (Pomplun, Sichelschmidt, Wagner, Clermont, Rickheit, & Ritter, 2001), two halves of a display (12, 15, or 18 items per half) contained visual primitives of various shapes (circles, triangles, squares) and colors (green, blue, red). On 50% of trials, a single primitive differed between the two halves in form, color, or form/color; on the other 50% of trials, the two halves were identical. The observers' task was to make a yes/no decision to the presence of the different primitive. Eye movements and response latency and accuracy were measured. In other studies, age-group differences in many of the sub-components of this task (e. g. feature search, VSTM capacity, and memory for oculomotor search) have been found to be minimal. However, the comparative search task produced age-group decrements in various measures, including response time, numbers of fixations, numbers of target rechecks, and target fixation time. Older adults did not show strategy differences: saccade amplitude and various measures of scan-path efficiency were similar across age group. Results indicate that older adults experience decrements when it is necessary to coordinate multiple elementary processes.
NIA RO1 AG20860-03