The effects of age and task demands on visual selective attention.

We investigated whether young and older adults differ on measures of interference (INT), negative priming (NP), and inhibition of return (IOR) on a spatial selective attention task that gradually increased in cognitive demand, from simple perceptual matching to letter identification. For both groups, INT increased and IOR decreased with task demand; while NP remained stable. We found age-related increases in INT, NP, and IOR, independent of task demand. However, only between-groups differences in IOR remained after correcting for age-related slowing in response times. Finally, we found no association between our measures of attention across groups, suggesting negligible overlap between INT, NP, and IOR. Our results indicate that attention is selectively and independently influenced by age and task demands, with both effects dependent on how attention is measured. These findings shed light on the "frontal hypothesis of aging."