Color heterogeneity in visual search

Distractor color heterogeneity refers to a condition in which a target is presented among distractors of different chromaticities. In the present study, the amount distractor color heterogeneity was varied systematically to determine how efficiently the visual system processes displays composed of search elements of multiple colors. Distractor color heterogeneity was expressed by selecting distractor chromaticities from sectors of various angles in a cone‐based normalized color space. The generalizability of the measurements was tested using two different visual search paradigms. An accuracy search task was used in which the search displays were presented as brief flashes and the dependent variable was search accuracy. A latency search task was used in which the display presentation time was under the participant's control and the dependent variable was reaction time. Compared to a homogeneous condition with distractors of a single color, distractor color heterogeneity had a deleterious effect on search performance in both paradigms. In normalized units, the measurements were similar across participants, target chromaticities, and tasks, but the same measurements expressed in non‐normalized units showed clear and systematic individual differences. © 2010 Wiley Periodicals, Inc. Col Res Appl, 2011