Abstract
The role of memory for target locations in visual search has been the subject of considerable research, with important implications for naturalistic search – wherein target and distractor configurations are typically quite stable over time. In previous research, the authors have provided evidence that the use of memory during search is at least partly dependent on the difficulty of search (Solman & Smilek, 2012). In particular, it is proposed that as purely random (or ‘brute force’) search becomes more costly, searchers are more likely to use memory. This results in more robust effects of memory on search times and efficiencies when comparing search through repeated versus non-repeated displays. In the present work, we extend these findings to the embodied realm. Contrasting eye-driven and head-driven search, we examine search performance in repeated and non-repeated displays, evaluating RTs, slopes, and early orienting performance. In the eye-driven condition, participants searched via a gaze-contingent window with head position fixed. In the head-driven condition, we used motion-tracking equipment to produce a head-contingent window. By using a large screen and holding position constant, all stimulus dimensions including window size were matched across conditions with respect to visual angle. Comparing these conditions tests the hypothesis that there will be enhanced memory effects in head-driven search, extending the difficulty-dependent memory use hypothesis to the realm of physical / energetic cost. The results are particularly important in light of the necessary recruitment of multiple motor systems during naturalistic search, and suggest that caution is warranted when interpreting higher-order cognitive influences on search using only eye-movements.
Meeting abstract presented at VSS 2013