Why does a matching distractor grab attention in the first place?
Working memory is the small mental workspace where you hold something in mind—a color, a shape, a face—for a few seconds. When something in the environment resembles what you're holding there, your attention tends to jump toward it, even when you're trying to look elsewhere. This is sometimes called "attentional capture," and it is the core problem that suppression has to solve.
The pull is measurable. When researchers tracked eye movements while people searched a display, a distractor that matched the color held in working memory captured gaze far more often than a distractor that didn't match—roughly a fourfold difference in that study [3]. So the first asymmetry between matching and non-matching distractors is simply that matching ones are harder to ignore from the start.
Suppressing a matching distractor takes active effort
Because matching distractors pull so hard, the brain doesn't just let them fade—it appears to actively suppress them. Electrophysiological recordings show signatures of active suppression directed at distractors that match working memory contents, and these markers distinguish matching from non-matching distractors [1]. In plain terms, the brain treats a matching distractor as something to be pushed down, not merely something to be overlooked.
That suppression may carry a side effect. The same work links this inhibition to a lower affective evaluation of the matching distractors—that is, people rated them less favorably—suggesting that the act of suppressing something can make it feel less pleasant [1]. This is presented as a possible link rather than a proven cause, but it hints that suppressing matching distractors is an effortful, evaluative process rather than a neutral filter.
Who suppresses well, and when does it happen?
Suppression ability isn't uniform across people. In a study of 51 adults, people with high visual working memory capacity were actually more susceptible to capture by target-matching distractors at first—their brains showed a larger early attention signal toward the distractor—but they then deployed a stronger later suppression response [2]. Low-capacity individuals showed the opposite pattern: less initial capture but weaker subsequent suppression. So the difference between groups isn't simply "good suppressors versus bad suppressors"; it's a difference in timing, with high-capacity individuals paying an early cost and recovering through stronger reactive suppression [2].
Timing matters within a single person, too. The guidance of attention by irrelevant working memory contents appears to be transient—it fades over time—and suppression is thought to be what prevents that guidance from causing prolonged distraction [5]. In other words, the matching distractor's advantage is short-lived precisely because suppression kicks in to cut it off.
How precisely you hold something changes how much it distracts
How strongly you maintain a memory also shapes the contest. When participants had to hold a color with high precision, matching distractors captured more attention and the working memory representation was reactivated more often than under a low-precision requirement [4]. Brain imaging showed greater activity in visual cortex for matching versus mismatching distractors at around 224 milliseconds during search under high precision [4].
The same study suggests a division of labor: reactivation of the memory representation during search directly predicted how much the matching distractor captured attention, while reactivation before search influenced capture indirectly, through its effect on distractor suppression [4]. So suppression and memory reactivation appear to work together—the stronger and more precise the memory, the more there is to suppress, and the more suppression matters.
Sources used in this answer
Neural evidence that inhibition is linked to the affective devaluation of distractors that match the contents of working memory
Electrophysiological markers show active suppression of distractors that match working memory contents, and these matching distractors were rated less favorably than non-matching ones, linking inhibition to affective devaluation.
Susceptibility to Attentional Capture by Target-Matching Distractors Predicts High Visual Working Memory Capacity
High visual working memory capacity individuals showed larger early attention capture by target-matching distractors but stronger subsequent reactive suppression than low-capacity individuals.
Multiple states in visual working memory: Evidence from oculomotor capture by memory-matching distractors
A working-memory-matching distractor produced greater oculomotor capture than a non-matching distractor (about 26% versus 6%).
The Reactivation of working memory representations affects attentional guidance
Under high-precision memory requirements, matching distractors captured more attention and working memory representations were reactivated more often, with reactivation during search predicting capture and pre-search reactivation acting through distractor suppression.
Guidance of attention by irrelevant contents of working memory is transient.
Guidance of attention by irrelevant working memory contents is transient, and suppression is discussed as a mechanism to avoid prolonged distraction from matching features.