Signal Intrusion Explains Divergent Effects of Visual Distraction on Working Memory

Perceptual distraction distorts visual working memories. Recent research has shown divergent effects of distraction on memory performance, including attractive biases, impairment of memory precision, and an increase in the guess rate, indicating multiple mechanisms of distraction interference. Here we propose a novel signal-intrusion model based on the TCC (target-confusability-competition) framework to reconcile those discrepant results. We hypothesized that sensory interference is driven by the integration of a target signal and an intrusive distractor signal. Model comparisons showed that this TCC-intrusion model had a superior fit to memory error distributions across three delayed-estimation tasks with distraction (N = 220 adults) compared with other candidate models. According to the model, distractor intrusions decreased along with target-distractor dissimilarity, in accordance with the sensory-recruitment hypothesis. Moreover, TCC-intrusion successfully replicated divergent effects of distraction on memory bias, precision, and guess rate using this one intrusion mechanism. Together, these results suggest that perceptual distractors affect working memories through a unified mechanism of signal intrusion.