Aging and the time course of inhibition of return in a static environment

Age-related differences on the time course of inhibition of return (IOR), a phenomenon that refers to a slowed response time for targets appearing at a previously attended location, were examined in 30 young and 30 elderly adults. Stimulus onset asynchronies (SOAs) between peripheral cues and targets were systematically manipulated on a detection task with a double-cue procedure to capture the onset and offset of IOR. Results show that IOR in elderly people developed 50 ms later as compared to young adults, at an approximately 200 ms cue-target interval. The magnitude of IOR for elderly people was also weaker than that for young adults during short SOAs. Similar magnitude and dissipation of IOR at an approximately 3.5 s cue-target interval during long SOAs were observed for both young and elderly people. Possible reasons underlying the age effects on the time course of IOR and the involvement of temporal processing mechanisms are discussed.