The Consequences of Processing Goal-Irrelevant Information During the Stroop Task

Recent evidence indicates that older adults' decreased ability to inhibit irrelevant information may lead to increased processing and greater memory for distractor information compared with younger adults. The present experiments examine the generality of this finding in a series of Stroop studies. In Experiment 1, participants studied a list of words then received a Stroop color naming task, with to-be-remembered words embedded within the Stroop task. Although there was evidence of a disproportionate age-related Stroop effect, there was no evidence of an age difference in episodic recognition memory for words from the Stroop task. Experiment 2 extended this paradigm to a more implicit demasking task. Again, there was evidence of an age-related disproportionate Stroop effect, however, there were no differences in memory for unattended words in demasking performance. Experiment 3 was a direct replication of a previous study which reported age differences in the influence of unattended words, via implicit priming in a general knowledge test. The results did not replicate the original study such that younger adults showed slightly more priming from distractors than older adults. The results provide converging evidence that although older adults have more difficulty inhibiting irrelevant information in the Stroop task, distractor information does not seem to disproportionately influence later memory for older adults compared with younger adults. These studies suggest that it is critical to consider the locus of memory encoding in distractor tasks to better understand the relationship between inhibitory processes during the distractor task and later memory performance.