Selective attention in younger and older adults
Three experiments are presented that investigated the effects of distracting information on the processing of stimuli for younger and older adults. The first two experiments were controlled laboratory experiments, in which the flanker paradigm was used to investigate whether older and younger adults were affected differently by response compatible or incompatible information. Typically performance measures indicate better performance in terms of reaction times if distracting information is response compatible and reduced performance if distracting information is incompatible with a response to be executed. As an additional variable, the stimulus-to-response mapping was manipulated to investigate whether younger but not older adults were able to reduce the influence of interfering information. The stimulus-to-response mapping was either consistent or varied, and it was assumed that varied but not consistent mapping allowed subjects to reduce the interfering effects of response-incompatible information. The data in the first experiment indicated no differences between younger and older adults. However, the data in the second experiment showed that younger but not older adults were able to reduce the processing of irrelevant information. A reduction of interference in the varied mapping condition could be observed only for younger but not for older adults. Subsequently, the results of these experiments were modeled by means of a connectionist network. The test of the network using linear regression indicated a good fit between the model and the empirical data, separated by each age group, indicating the appropriateness of the theoretical assumptions of the model. The third experiment investigated the effect of compatibility using realistic stimuli, i.e., traffic signals and signs, in order to determine how compatibility governs performance in a more applied setting. No specific age-related performance deficits were observed, however, both age groups benefited from compatible information. This allowed us to derive recommendations for the design of traffic signals and signs.