Using the dual-target cost to explore the nature of search target representations

J Exp Psychol Hum Percept Perform. 2012 Feb;38(1):113-22. doi: 10.1037/a0025887. Epub 2011 Oct 17.

Abstract

Eye movements were monitored to examine search efficiency and infer how color is mentally represented to guide search for multiple targets. Observers located a single color target very efficiently by fixating colors similar to the target. However, simultaneous search for 2 colors produced a dual-target cost. In addition, as the similarity between the 2 target colors decreased, search efficiency suffered, resulting in more fixations on colors dissimilar to both target colors, which we describe as a "split-target cost." The patterns of fixations provide evidence to the type of mental representations guiding search. When the 2 targets are dissimilar, they are apparently encoded as separate and discrete representations. The fixation patterns for more similar targets can be explained with either 2 discrete target representations or a single, unitary range containing the target colors as well as the colors between them in color space.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Color Perception / physiology*
  • Eye Movements / physiology*
  • Fixation, Ocular / physiology*
  • Humans
  • Models, Psychological
  • Neuropsychological Tests
  • Pattern Recognition, Visual / physiology*
  • Young Adult