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Precedence of the global over the local level in visual perception is well established by the use of compound, or hierarchical, stimuli. However, (a) virtually nothing is known concerning the fate of global precedence with normal aging, and (b) there is still a debate about the early versus late perceptual locus of the effect. The present study was planned to investigate both topics. Two experiments are reported where young adult and elderly subjects were enrolled for the recognition of compound letters either at the global or at the local level. In order to recruit late perceptual processes, the case of the letters varied in such a way that subjects had to activate graphemic codes to take their decision. It appeared that the global precedence effect was preserved. This observation shows an early perceptual source of the global precedence effect, which is then transferred to later stages of information processing. Age did not affect the global precedence phenomenon.

To test different hypotheses about age-related slowing of word and picture naming, response latencies of young and older adults were compared in 2 experiments using the same 4 tasks: picture naming, written word pronunciation, and picture and word categorization. In each case, the target word or picture was presented with a distractor word that had to be ignored. Analyses showed the expected main effects of age, modality, and interference conditions but no consistent interaction between age and other factors. More particularly, age-related slowing was similar in word and picture processing and interference was proportional to overall speed of responding. Thus, no support was found for the hypotheses assuming either declining inhibitory mechanisms or task-specific deficits in older adults. These results were discussed in relation to characteristics of the experimental tasks.