The effect of background color on asymmetries in color search

Abstract

Many previous studies have shown that background color affects the discriminability and appearance of color stimuli. However, research on visual search has not typically considered the role that the background may play. Rosenholtz (2001a) has suggested that color search asymmetries result from the relationship between the stimuli and the background. Here we test the hypothesis that background color should have an effect on asymmetries in visual search based on color, using searches for color stimuli on different colored backgrounds. Observers searched for a single known target stimulus among homogeneous distractor stimuli. The target stimulus differed from the distractors only in chromaticity, but targets and distractors both differed from the backgrounds in luminance so that they were easily visible regardless of chromaticity. Target/distractor pairs differed primarily in saturation (Experiments 1, 2, & 3) or in hue (Experiment 4). Each member of each pair of colors served as target and distractor color on both achromatic and red backgrounds. When the stimuli were presented on an achromatic background, response times were shorter when the more saturated member of each pair of colors served as the target color. When the same stimuli were presented on a red background, the asymmetry was either reversed or abolished. When target and distractors differed in hue, there was little asymmetry on the achromatic background but a sizable asymmetry for some color pairs on the red background. On both backgrounds, the magnitude of the asymmetry varied with the difference between the stimulus colors and the background color. Results confirm that asymmetries in color search are dependent on the relationship between the stimulus colors and the background color. Two candidate models are suggested that show promise in predicting these experimental results: Rosenholtz' saliency model (1999, 2001a) and a modification to signal detection theory models in which the observation noise is proportional to the difference between target/distractor color and background color.

Do honeybees detect colour targets using serial or parallel visual search?

“…In humans, it is known that relative contrast between object and background can generate search asymmetries (Nagy and Cone, 1996;Rosenholtz et al, 2004). If search asymmetry in bees is caused by a similar mechanism as in humans, we would predict a lower bee-subjective colour contrast between the blue target and the background and a higher contrast for the yellow target.…”

“…(2) Decision time and error rate are higher when bees search for a blue target within yellow distractors than when they search for a yellow target within blue or mixed-coloured distractors. Bees exhibit a clear search asymmetry in colour search, which is also found in humans when the colours of the target and distractors differ in hue and saturation (Rosenholtz et al, 2004). (3) When target number increases, error rate and decision time decrease.…”

Visual saliency estimation by nonlinearly integrating features using region covariances

“…In a related discussion, Eckstein et al (2000) suggested that the difficulty in searching for conjunctions (Treisman & Gelade, 1980) can be explained by examining the target and the distractors in a high-dimensional visual feature space and by looking into the feature dimensions along which the distractor and the target differ. Similarly, Rosenholtz (1999Rosenholtz ( , 2001 and Rosenholtz et al (2004) suggested that the covariance of the distractors in a higher dimensional feature space may provide an explanation for the difficulty of searching a target in motion or in different color.…”

“…However, it is important to note that a limited number of studies have addressed how different feature dimensions contribute to the overall saliency (Callaghan, 1989(Callaghan, , 1990Eckstein, Thomas, Palmer, & Shimozaki, 2000;Rosenholtz, 1999Rosenholtz, , 2001Rosenholtz, Nagy, & Bell, 2004). For instance, it has been argued that for certain tasks some visual features may become visually more salient than others.…”

An Object-Based Visual Selection Model Combining Physical Features and Memory

“…In this scenario, according to [23], [24], and [20], when an object has a certain contrast in relation to the others, it should receive the attention. Then the images 5 and 6, we consider the theories presented in [18] and [25], which is based on the asymmetry credited to the presence or absence of salient features for delivering the attention. In these images, the task of finding the object "+" among "-" is easier than finding the "-" among "+", however the salience should exist in both tasks.…”