Get Your Guidance Going: Investigating the Activation of Spatial Priors for Efficient Search in Virtual Reality

Abstract

Repeated search studies are a hallmark in the investigation of the interplay between memory and attention. Due to a usually employed averaging, a substantial decrease in response times occurring between the first and second search through the same search environment is rarely discussed. This search initiation effect is often the most dramatic decrease in search times in a series of sequential searches. The nature of this initial lack of search efficiency has thus far remained unexplored. We tested the hypothesis that the activation of spatial priors leads to this search efficiency profile. Before searching repeatedly through scenes in VR, participants either (1) previewed the scene, (2) saw an interrupted preview, or (3) started searching immediately. The search initiation effect was present in the latter condition but in neither of the preview conditions. Eye movement metrics revealed that the locus of this effect lies in search guidance instead of search initiation or decision time, and was beyond effects of object learning or incidental memory. Our study suggests that upon visual processing of an environment, a process of activating spatial priors to enable orientation is initiated, which takes a toll on search time at first, but once activated it can be used to guide subsequent searches.

Keywords: incidental memory; repeated search; virtual reality; visual search.

Figure A1

Response times for the first and the subsequent trials as a function of scene revisits. Error bars depict within-subject standard errors.

Figure 1

Bird’s-eye view of one of the bathrooms and one sample view of all the scenes that were used in the experiment. Blue squares indicate the starting position of the participants and were not visible during searching.

Figure 2

The procedure of the repeated visual search task. For visualization purposes, the cue is shown in English here but was presented in German in the original experiment. Cue and fixation cross are enlarged to increase legibility.

Figure 3

SIE in response times. (a) depicts the response times for all searches in a scene visit. (b) contains the same data as (a) but response times of the second to the fourth trial are shown as an average. (c) shows the difference between the response time of the first trial and the average of the second to the fourth trial. Higher values indicate a larger response time for the first trial than the subsequent trials, while the dashed line indicates the point of no difference in response times between trials. Capital letters indicate conditions, C = Control, I = Interruption, P = Preview. Error bars indicate within-subject standard error. n.s. = not significant, * p < 0.05, *** p < 0.001.

Figure 4

Difference between the time of the first trial and the average of the second to fourth trial for (a) search initiation time, (b) time to first target fixation, and (c) decision time. Plots are ordered in their chronological appearance during searching. Higher values indicate a larger response time for the first trial than the subsequent trials, while the dashed line indicates the point of no difference in response times between trials. Error bars indicate within-subject standard error. For reading purposes, we only denoted significant comparisons. *** p < 0.001.

Figure 5

SIE in response times only for trials in which the target object has been fixated previously. (a) depicts the response times for the first trial in a scene visit and the average of the response times of the second to the fourth trial. (b) shows the difference between the response time of the first trial and the average of the second to the fourth trial. Higher values indicate a larger response time for the first trial than the subsequent trials, while the dashed line indicates the point of no difference in response times between trials. Error bars indicate within-subject standard error. n.s. = not significant, * p < 0.05., ** p < 0.01, *** p < 0.001.