Stage-Specific Effects of Spatial Organization on Visual Search Under Clutter: Behavioral and Eye-Movement Evidence

Whether a well-organized scene facilitates visual search may depend on when in the search process the benefit is expressed. We tested this possibility in a virtual-office task in which 48 adults searched for targets varying in salience. Salience was manipulated between participants, whereas layout (grid, clustered, or random) and clutter (low, medium, or high) varied within participants. Mouse responses and eye position (120 Hz) were collected across 1296 target-present trials. Accuracy was broadly comparable across conditions, but reaction time (RT), time to first fixation (TTFF), fixation duration in the Target AOI, and fixation duration in the Clutter AOI each showed a three-way interaction. The transition data were particularly informative under high clutter. For grid layouts, clutter-to-target transitions occurred on 47.3% of transitions, clutter-to-clutter self-transitions on 20.5%, and the target was first reached after 0.89 intervening transitions on average. The respective values for random layouts were 11.2%, 64.2%, and 6.39. Thus, the benefit of the grid was not consistently present at initial target capture. It became most evident in the way gaze was redirected among regions as the search unfolded. Spatial regularity therefore seems to limit later search costs by making attentional reallocation and gaze-path correction more efficient.