Fur in the midst of the waters: visual search for material type is inefficient.

A limited set of attributes can guide visual selective attention. Thus, it is possible to deploy attention to an item defined by an appropriate color, size, or orientation but not to a specific type of line intersection or a specific letter (assuming other attributes like orientation are controlled). What defines the set of guiding attributes? Perhaps it is the set of attributes of surfaces or materials in the world. L. Sharan, R. E. Rosenholtz, and E. H. Adelson (submitted for publication) have shown that observers are extremely adept at identifying materials. Are they equally adept at guiding attention to one type of material among distractors of another? A series of visual search experiments shows that the answer is "no." It may be easy to identify "fur" or "stone," but search for a patch of fur among the stones will be inefficient.