Abstract
Visual search asymmetry is a phenomenon in which search efficiency changes in accordance with a swapping target and distractor, and which has been observed with a variety of target types. Previous studies assume that search asymmetry is achieved due to the difference of activation, which is calculated by considering each feature separately (e.g., color, orientation, and intensity). According to this prediction, for each participant, search asymmetry would be consistent across a target type, if the target is defined by the same feature dimension. In this study, we used four types of stimulus sets: circle/circle with line, vertical/tilted lines, longer/shorter lines, and familiar/mirror-reversed Chinese characters. Circle/circle with line search is based on the appearance of one element, vertical/tilted and longer/shorter line searches are based on the difference in the feature amount, and Chinese/mirror-reversed Chinese character search is based on familiarity. Moreover, the first two stimulus sets lead to pop-out search, whereas others lead to inefficient search. For the vertical/tilted line search and familiar/mirror-reversed Chinese character search, the target was defined by the difference of orientation of a line. The results indicated that although search asymmetry was observed in all stimulus types, personal performances were inconsistent across target types and target presence. An exploratory factor analysis and correlation analysis demonstrated that search asymmetries in target-present and absent trials were due to the different structures of the factors. Specifically, for target-present trials, asymmetries in orientation and Chinese character searches were correlated, whereas for target-absent trials, asymmetries in circle/circle with line and orientation searches, and those in line length and Chinese character searches were correlated, respectively. These results suggest that i) consistency in the intensity of search asymmetry depends on the feature property in the target-present trials, and ii) the search asymmetry in target-absent trials is affected by the search strategy.
Meeting abstract presented at VSS 2015