Effects of irrelevant information on speeded classification tasks: Interference is reduced by habituation

Irrelevant information becomes less distracting as a task is practiced. Previous research has suggested that the habituation of responses to irrelevant stimuli may account for the improvement. Two experiments, using 90 and 48 undergraduates, tested the habituation explanation as an account of reductions in interference in a speeded classification task. Exp I tested the prediction that interference from irrelevant stimuli would be reduced by incidental preexposure to the irrelevant stimuli prior to the classification task. The results were affirmative. In Exp II, Ss were trained on a discrete trial speeded classification task in which irrelevant stimuli were present on some trials. They were then given transfer tasks in which the relevant classification was unchanged but in which various novel irrelevant stimuli were shown on some trials. Results confirm detailed predictions based on the habituation hypothesis. A large interference effect was produced by the introduction of irrelevant stimuli on new dimensions. These novel stimuli also produced reinstatement of interference by the original irrelevant stimuli and disruption of baseline (no irrelevant stimuli) trials. Findings have implications for concepts of automatic processing and attention. (44 ref) (PsycINFO Database Record (c) 2006 APA, all rights reserved).