Abstract
Previous research has shown that information that is task-relevant is retained over time and protected from posterior interference (e.g. Maxcey-Richard & Hollingworth, 2013). To examine whether location information is acquired and persists over the time course of natural actions we had participants perform a visual search task in an immersive virtual reality apartment. Participants searched the two rooms that formed the apartment for a series of geometric target objects, which were always visible. Eye movements, head movements and body trajectories were recorded. Target locations were manipulated to see if participants took advantage of regularities in the environment. Specifically, all target objects (8) were presented at the same locations in blocks 1, 2, 3 and 5, but switched location in each trial during block 4. We analyzed search time and number of errors (visits to wrong room) per block of 8 trials. Average search time decreased significantly between blocks 1 and 3 and then increased significantly in block 4. Interestingly, search time decreased again in block 5, once objects returned to their locations, with averages significantly lower than those of block 3. Room errors increased to 50% in block 4 but decreased significantly in block 5 to values similar to those of block 3. Gaze content also showed that about half of the participants used a memory-based strategy for finding the objects in block 4: on 28% of the trials these participants' first object fixation was on the object now occupying the location where the target used to be in blocks 1 to 3. From these three results we conclude that participants retained target location information from previous trials and used this information to make their search more efficient (i.e. block 5). The unreliability of object locations during block 4 was not enough to overwrite the information acquired during the first three blocks.
Meeting abstract presented at VSS 2016