Abstract
Do the semantic associations of alphanumeric characters influence the efficiency of visual search? Attempts to answer this question have typically suffered from a confound between conceptual and perceptual features because manipulating the meaning of an alphanumeric character entails manipulating its shape as well. By carefully controlling shape features, Lupyan (2008) found an influence of letter category on visual search. Here we extended these findings to visual search for digits and wondered if numerical and physical size would interact to yield faster response times when the two are congruent than when incongruent. The numbers 2, 3, 8, and 9 were used for search items in all conditions. In congruent conditions the numerically larger digits were slightly physically larger than the numerically smaller digits and vice versa for the incongruent conditions. In the larger magnitude conditions targets were numerically larger (8 and 9) among numerically smaller distractors (2 and 3) and vice versa for the smaller magnitude conditions. Eighty participants were randomly assigned to one of four conditions: larger magnitude/congruent, larger magnitude/incongruent, smaller magnitude/congruent, and smaller magnitude/incongruent. Each search array contained one of the two target digits and varying numbers (4, 6, or 8) of distractors. Participants indicated the side of the display containing the target with a keypress. Mean correct response times were submitted to ANOVA to compare differences between congruent/incongruent, numerically larger/smaller, and physically larger/smaller conditions. Only the congruent/incongruent comparison yielded significant differences. As hypothesized, visual search is faster when semantic and physical attributes are congruent than when incongruent. Perhaps the mismatch interferes with the maintenance of a complex target template. Future studies will explore this possibility by determining the effect of congruence on search for a single target.
Meeting abstract presented at VSS 2014