Visual attention research has identified the shared-feature effect, where disengagement from a fixated stimulus is delayed when it shares characteristics with a target. To better understand this phenomenon, we investigated three key questions: (1) Does the effect weaken as fewer features are shared? (2) Do certain features (color, shape, object) play dominant roles? (3) How do feature combinations influence attentional capture?

We conducted an eye-tracking experiment using a visual search paradigm previously described by Saalwirth et al. (2024). Participants focused on a central picture and then searched for a target in an outer circle of six images, responding to whether the target's orientation was left or right. The central picture shared varying degrees of features with the target: none, one feature (color, shape, or object), two features (color & shape, color & object, or shape & object), or all features.

Results indicated that the shared-feature effect diminished as fewer features were shared with the target picture. Color emerged as the most prominent feature, followed by object, and shape. This hierarchy was also evident in two-feature combinations, where pairings that included the same color led to a stronger delayed disengagement. These findings enhance our understanding of the shared-feature effect's nuances and the relative importance of different stimulus features in visual attention processes.