Repelling the young and attracting the old: examining age-related differences in saccade trajectory deviations

In the present study, the authors examined age-related differences in saccade curvature as older and younger adults looked to an X target that appeared concurrently with an O distractor. They used a fixation gap procedure to introduce variance into the saccadic latencies of both groups. Consistent with earlier findings, younger adults' early onset saccades curved toward the distractor (as the distractor competed with the target for response selection), while late-onset saccades curved away from the distractor (as the distractor location became inhibited over time). In contrast, older adults' saccades gradually decreased in curvature toward the distractor, but at no point along the latency continuum did they show deviations away. These results suggest that while the local inhibitory mechanisms responsible for decreases in curvature toward distractors may be preserved with age, aging may lead to a selective decline in the frontal inhibitory mechanisms responsible for deviations away from distractors.