Distinct Cortical and Oculomotor Dynamics During Endogenous and Exogenous Competition in Working Memory

Working memory (WM) enables the temporary maintenance of information for guiding thought and action, but its limited capacity requires internal selective attention mechanisms to prioritize goal-relevant representations. Like external attention, internal selection can be shaped by both endogenous (goal-driven) and exogenous (stimulus-driven) factors. Classic work by Charles Folk and Roger Remington demonstrated that such factors interact competitively during external attention, producing stimulus-driven capture under certain conditions. Whether similar competitive dynamics govern internal selection remains unclear. Prior studies using retro-cue paradigms with extended cue-response delays have reported evidence for "retro-capture"--involuntary orienting toward task-irrelevant but cue-matching working memory content. Here, we combined EEG and eye-tracking to test whether retro-capture persists when the cue and response probe are simultaneous, eliminating the temporal window in which capture has previously been observed. Participants remembered two oriented bars and used either a pro-cue or an anti-cue to guide recall. Across behavioral, cortical, and oculomotor measures, we found no evidence for retro-capture. Instead, competition between endogenous and exogenous selection mechanisms uniformly delayed the selection of task-relevant WM content, with delays evident in response times, lateralized alpha-band activity, and gaze biases toward remembered locations. Our findings indicate that retro-capture is not an obligatory consequence of endogenous-exogenous competition in WM but may depend on the temporal separation between cue and action.