ADULT AGE-DIFFERENCES IN ATTENTION - FILTERING OR SELECTION

We examined the effect of target letter redundancy for target-only (TO ) and target-plus-noise (TPN) trials on a visual search, divided atten tion task where target letters,cere presented in one or two corners of a two-corner display. Half of the two-letter displays also included a noise letter. In both Experiment I (two-choice vs go/no-go) and Exper iment 2 (all go/no-go), older adults showed larger redundancy gains th an did young adults, and this effect did not interact with task type o r visual similarity. However, for the ''no-go'' trials in both experim ents, there were no age differences in overall errors. These results s uggest that there are age differences in the activation of selective a ttention rather than age differences in inhibitory control. In Experim ent 2, young adults under lower-luminance presentation conditions (18 cd/m(2)) showed a smaller redundancy gain than did older adults under higher-luminance presentation conditions (40 cd/m(2)). These results p rovided further support of the age differences in activation interpret ation, as well as indicating that older adults' larger redundancy gain was not due to an age decrement in retinal illuminance.