Abstract
The role of memory in guiding attention in real scenes is complex. One way that experience might guide search is by reducing the areas of the scene searched and directing search away from irrelevant regions (Neider and Zelinsky, 2008, Wolfe et al., 2011). We explored whether this is a significant factor in guiding search in immersive natural environments. We performed the search task in a 3D virtual environment, as well as in a 2D version that was parallel in task structure. Subjects searched for targets that were located on one of four surfaces in either of two rooms. We investigated the source of improvement from learning the space at both global and local levels: i) which room contains the target and ii) in which part of that room the target is located. We found that the probability of choosing the correct room to search on first entry is higher in 3D than in 2D, and improves in both cases. The number of room entries required to find the targets was also lower in 3D and decreased over episodes. More fixations inside the rooms are directed to surfaces that potentially contain targets in both 2D and 3D (increased from 60 to 87 of fixations after 24 trials in 3D). Surface fixations even early in the experiment indicate the influence of prior scene knowledge. Together these results indicate that memory representations facilitate search by restricting attention to the relevant parts of the environment while excluding the irrelevant parts at the global level (choosing the correct room) and also at the local level (looking at relevant regions inside the room). In addition, the data also suggest that global memory is used more in 3D, potentially because of the higher energetic or temporal cost of changing the region to be searched.
Meeting abstract presented at VSS 2016