Gaze patterns reveal attention-based modulation of lure discrimination.

The ability to differentiate highly overlapping stimuli or experiences in memory (and the behavioral lure discrimination outcomes that reflect this ability) has traditionally been studied as a mnemonic process. However, the contribution of goal-directed attentional processes, involved in a similar interference resolution function, has yet to be examined. Using eye-tracking, we first show that eye movements can be used as a sensitive measure of behavioral lure discrimination, based on performance on the widely used Mnemonic Similarity Task (Experiment 1). We then show in three separate experiments that a gaze-based measure of lure discrimination is modulated by attentional priorities induced through manipulation of task goals during a perceptual discrimination task (Experiments 2-4). Specifically, prioritizing attention to objects in "relevant" categories attenuated lure discrimination for objects in "irrelevant" categories. When task demands were equated across conditions, lure discrimination was enhanced for objects in "relevant" categories (Experiment 4). Finally, gaze-based lure discrimination predicted subsequent memory quality on a surprise memory task. The present findings provide critical evidence that behavioral lure discrimination can be modulated by changes in attentional priorities, and more broadly, that goal-directed attentional processes mediate the extent to which similar inputs are discriminated in memory.