Gating processes that regulate sensory input into visual working memory (WM) and the execution of planned actions share neural mechanisms, suggesting a mutual interaction. In a preregistered study (OSF), we examined how this interaction may result in sensory interference during WM storage using a delayed-match-to-sample task. Participants (12 male, 20 female) memorized the color of a target stimulus for later report on a color wheel. The shape of the target indicated which hand they would adjust the color wheel with. During the retention interval, an interference task was presented, requiring a response with either the same or different hand as the main task. In half of the interference trials, the interfering task cue was also colored to introduce visual interference. EEG results showed early motor planning during sensory encoding, evidenced by mu/beta suppression contralateral to the responding hand. The interference task only impaired WM performance when it included an irrelevant color, indicating that the interference effect was primarily driven by the irrelevant sensory information. In addition, color reporting in the WM task was biased toward the irrelevant color. This was more pronounced when both tasks were performed with the same hand, suggesting a selective gating mechanism dependent on motor control processes. This effect was mitigated by a control mechanism, which was evident in frontal theta activity, where higher power predicted lower bias on the single-trial level. Our findings thus reveal that sensory WM updating can be induced by interfering motor actions, which can be compensated by a reactive control mechanism. Significance statement Working memory is increasingly recognized not just as a passive information storage but as an active mechanism that constructs prospective representations to guide future actions. We investigated how future-oriented plans regulate the entry of new information for maintenance. We found that when a stored memory is linked to a response, it becomes particularly vulnerable to interference from sensory input that demands the same response. We also identified neural signatures of this interaction where a control mechanism mitigates interference from irrelevant information. These findings provide key insights into the fundamental architecture of memory, demonstrating for the first time that prospective motor codes not only shape the use of stored information but also influence how new information is integrated into working memory.
Özdemir et al. (Thu,) studied this question.