Visual similarity is stronger than semantic similarity in guiding visual search for numbers
56.427, Tuesday, 20-May, 2:45 pm - 6:45 pm, Banyan Breezeway
Tamaryn Menneer1, Hayward, J. Godwin1, Michael, C. Hout2; 1Centre for Vision and Cognition, Psychology, University of Southampton, UK, 2Department of Psychology, New Mexico State University, USA
The consideration of semantic information is becoming increasingly important in visual search and models of search (Wolfe, Võ, Evans & Greene, 2011), particularly in search of scenes, in which target semantics and scene context influence the location of eye fixations (e.g., Oliva & Torralba, 2007). With more abstract stimuli, search for the number 5 amongst distractor digits is slower and less accurate when distractors are semantically close numbers (3, 4, 6, 7) compared with distant numbers (1, 2, 8, 9) (Schwarz & Eiselt, 2012). The aim of the current experiment was to extend this previous study to assess the influence of visual similarity as well as semantic similarity in number search. Eye movements were recorded while participants searched for a target digit amongst other digits (e.g., 0 amongst 1-9). We examined the probability of fixating the various distractors as a function of two key dimensions: the visual similarity between the target and each distractor, and the semantic similarity (numerical distance) between the target and each distractor. A key requirement of this research was to quantify visual similarity, which was achieved using multidimensional scaling (MDS) of independent observer similarity ratings. The probability of fixating distractors was driven by both visual and the semantic similarity. However, in some contrast to previous findings, visual similarity played a larger role than semantic similarity in guiding search. These findings contribute to the growing literature of the relative importance of semantic and visual information in visual search, as well as providing a proof of concept for the usefulness of MDS as a tool for such studies.