Age differences in the useful field of view: an eye movement analysis.

Age differences in the useful field of view (UFOV) were examined by asking younger (mean age = 24 years) and older (mean age = 64 years) observers to search for two oriented line targets. These targets were presented at eccentricities ranging from 4 degrees to 14 degrees, and were embedded in either no distractors, homogeneous distractors, or heterogeneous distractors. Eye movements were recorded, along with reaction time (RT) and accuracy. The eye movement data indicated that older observers had more difficulty locating peripheral targets, particularly when they were embedded in heterogeneous distractors. Furthermore, the greater effects of eccentricity and distractor type found in the RT's of older adults were eliminated when age differences in saccade number were partialled out. These findings suggest that age differences in search are largely attributable to factors other than selective attention.