Abstract
Visual clutter (VC) is an inherent part of everyday environments. Previous studies have demonstrated that VC degrades search efficiency and alters eye-movement behavior. However, it remains unclear whether and how scene clutter influences learning and memory for spatial targets presented in naturalistic environments to which we are repeatedly exposed. To examine this, participants completed a search-based learning (SBL) task in which they had to detect and explicitly memorize the location of a target superimposed on natural scenes across four repeated blocks. Importantly, scenes differed in their level of clutter (low vs. high). After a break, participants performed a cued recall task that allowed us to examine their long-term memory for target locations in the previously-studied scenes. Behavioral results showed that participants were slower to detect the target in high- than in low-clutter scenes across all blocks, indicating that VC impacted negatively search time. Furthermore, in both clutter conditions, participants became faster at detecting the target in each successive block. Nevertheless, learning of target locations was faster (as indicated by steeper search slopes) for high- than for low-clutter scenes. Eye-tracking data showed that high scene clutter prolonged search initiation as well as scanning and target verification time. Critically, the decrease of search times over the blocks was driven by significant reductions in scanning and target verification time, but not initiation time, for both clutter scenes. Surprisingly, and despite faster learning of target locations in high- than in low-clutter scenes, participants recalled the locations of the target less precisely in high- than in low-clutter scenes during the cued recall task. Together, our findings suggest that the deleterious effects of VC on cognition and eye movements persist even after multiple exposures to the same environments. These findings have important implications for adaptive daily living as decluttering interior spaces might prove beneficial for cognition.