A series of 6 experiments investigated the use of cues and prompts by younger and older adults. Cues provide useful information about an impending target, even though the information is not always valid. Prompts provide an instruction about what aspect of the target is to be responded to. The costs and benefits of cues were most consistent with models in which the attentional resources that are shifted in response to the cue were as large or larger in older adults as they were in younger adults. The results with both cues and prompts converged on the conclusion that the time course of processing and using a cue or prompt is the same in younger and older adults. The attentional resources tapped by these procedures cannot be the diminished processing resource to which many age differences in cognitive performance are attributed.Poorer performance by older adults is common in a wide variety of tasks with a wide variety of measures of performance. The observed differences in performance may be explained parsimoniously by assuming that there are changes with age in one or a few basic mental resources, such as attention, that are fundamental to many cognitive activities.Theoretical difficulties with resource explanations for age differences on the basis of attentional resources have been pointed out (e.g., Salthouse, 1982Salthouse, , 1988aSalthouse, , 1988bSalthouse, , 1988c.Itis possible, however, to proceed without theoretical consensus on attention as a cognitive resource. Procedures can be found that can be agreed on as tapping one or another aspect of attentional processing. If age differences can be demonstrated in those procedures, then the tasks will provide operational indicators of attention, and variables that affected the age differences in performance could then be explored. If age

Responses to targets are slower when they appear at a location to which attention has previously been directed than when they appear at other locations. This inhibition of return (IOR) effect is subserved by posterior brain attentional systems. In 4 experiments the IOR effect in elderly adults was found to be at least as large as in young adults for both discrimination tasks and for detection tasks. The time course and the spread of inhibition within the visual field were also equivalent in the 2 age groups. Additive factors logic was then used to test the hypothesis that the Stroop and IOR effects are due to a common mechanism, a failure to suppress attention. This hypothesis was not confirmed. The results of the 6 experiments are consistent with the hypothesis that there are changes in posterior brain systems responsible for selective attention to a location, contrary to prior claims. They cannot be explained by a general slowing of processing in old age.

Previous failures to find reliable identity suppression (identity negative priming) in older adults have led to conclusions that older adults suffer from an impairment in the inhibitory component of selective attention. Here, 2 experiments using the Stroop procedure found identity suppression in older adults that was both reliable and equivalent to that in younger adults. Experiment 1 with repeated target colors produced correlations consistent with an episodic retrieval explanation of identity suppression, Experiment 2 without repeated targets produced correlations inconsistent with the episodic retrieval interpretation. These patterns were found for both younger and older adults. No evidence was found for reduced identity suppression that would be consistent with a general inhibitory impairment in older adults.

InYounger and older adults were compared in three experiments, using procedures that had been shown to affect the spread of visual attention. The attentional effects found in previous experiments were replicated. A broader focus of attention speeded responses to peripheral targets. In addition, two established findings concerning aging were replicated: Responses were slower in older than in younger adults, and, in certain conditions, they slowed more rapidly as target eccentricity increased. No interactions of age effects with attentional manipulations were found. The results of all three experiments were consistent with the interpretation that younger and older adults do not differ in the allocation of attention.

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