Aging modulates the effects of scene complexity on visual search and target selection in virtual environments

Processing task-relevant visual information is important for successfully completing many everyday tasks. Prior work demonstrated that older adults are more susceptible to distraction by salient stimuli, leading to less efficient visual search. However, these studies often relied on simple stimuli, and little is known about how aging influences visual attention in environments more representative of real-world complexity. Here, we test the hypothesis that aging impacts how the visual complexity of the environment influences visual search. We asked young and older adults to complete a virtual reality-based visual search task with three levels of increasing visual complexity. As visual complexity increased, all participants took longer to complete the task. This increase in time to completion resulted from two factors: an increased time required to transfer gaze from one target to the next as participants re-fixated task-relevant objects and longer lags between when correct targets were fixated and selected. We also found that these changes in gaze trajectory were greater in older adults. In addition, we found that short-term and working memory capacities were positively associated with multiple performance measures in the visual search task. This suggests that visual search performance could be integrated into assessments of working memory in dynamic environments.