Abstract
Working memory must persist through distraction to guide goal-directed behaviors. Prior research has consistently shown that memory reports are systematically biased towards distractors from the same feature space as memoranda, but the neural mechanisms that drive this effect are not well understood. We hypothesized that distractor interference could arise from memory representations being shifted towards the distractors or from distractor representations that linger in working memory. Here, we recorded EEG signals from N = 23 participants (M = 19.1 years, 20 females) while they performed a delayed-estimation task with a distraction task inserted into the delay period. Participants encoded two orientations and were provided with a retro-cue (80% validity) to prioritize one of them. A brief visual ping (3 white circles) was shown to reactivate memory representations before participants reproduced the probed orientation. In half of the trials, a sensory-motor distraction task was inserted into the delay period in which participants manually rotated a black bar to match the orientation of a white bar on the screen. Behavioral results showed reliable attractive biases towards distractors for both prioritized (3.0 °) and unprioritized memories (1.6 °). Multivariate EEG analyses revealed that the prioritized orientation was reliably decoded in trials without distraction, but not in trials that included distraction. In these trials, the distractor orientation was decoded instead, and larger attractive biases were found in trials that showed stronger distractor representations. Importantly, the loss of decodability of prioritized memories did not lead to catastrophic memory loss. These memories could have been preserved in another region or format to survive the distraction, or they could have been stored silently during distraction and then reactivated to guide memory responses. Regardless, these findings suggest that attractive biases in memory reports following distraction are driven by lingering distractor representations, not by biased memory representations.