The impact of orienting attention in fast task-irrelevant perceptual learning

Task-irrelevant perceptual learning (TIPL) refers to the phenomenon where the stimulus features are learned when they are consistently presented at behaviorally relevant times (e.g., with task targets or rewards). Studies on the role of attention in TIPL have found that attention negatively impacts this type of learning; however, these studies involved stimuli that were completely irrelevant to the subjects and that, when noticed, were distracting to the subjects' task. Here, we asked whether attention would have a beneficial impact on learning in the case where the target-paired stimuli were relevant to a secondary task that subjects were required to perform. We conducted three experiments in adult subjects, using the fast-TIPL paradigm (which allows one to study TIPL with as little as a single trial of exposure). The results from Experiments 1 and 2 showed that fast-TIPL occurred for the target-paired stimuli but that the manipulation of attention increased performance for stimuli presented after the target. Experiment 3 was conducted to address whether the direction of attention positively or negatively impacted fast-TIPL and to better control for the effects of attention. The results of this experiment demonstrate that in the case of fast-TIPL, exogenously directed attention aids in the memorization of target-paired stimuli. Overall, our results demonstrate that attention operates in a beneficial manner in fast-TIPL, where the target-paired stimuli are relevant to a secondary task that subjects perform.