Avery Caulfield¹, Justin Halberda², E. J. Green³; ¹Johns Hopkins University

The phenomenon of pop-out is commonplace in everyday experience and fundamental to studying the interface between early and mid-level vision (e.g., object-based representation). One question concerns how the visual system prioritizes features following pop-out. Does the feature that caused the pop-out get represented with higher priority or fidelity compared to the object’s other features? For instance, one might perceive a colored rectangular object among colored disks and perceptually represent, “that rectangle (pop-out feature) over there just happens to be red (ancillary feature)” Furthermore, given its task of reidentifying objects over time, it makes sense that the visual system would prioritize pop-out features. For example, if an object’s color is distinctive but its shape is not, then it can be reidentified more accurately using color. To explore the perceptual priority of pop-out features, 20 adults participated in a visual search and memory task using a staircase procedure. In each trial, participants viewed 9 objects, one of which was unique (a singleton, differing in color, orientation, or size) for 500 ms. Participants were asked to detect the unique object and remember its features. Following a 500 ms mask, participants clicked on the pop-out target's location. Then a probe item appeared in the same location as the target. The probe either matched the original or had one altered feature, with the degree of difference in the altered cases adapting to the participant's performance on each feature dimension. Results revealed a significant memory advantage for pop-out features over non-pop-out features, demonstrating that pop-out features are prioritized in visual working memory, supporting their enhanced role in the visual processing and reidentification of objects.