Visual search for size is influenced by a background texture gradient.

Research on the perception of texture gradients has relied heavily on the subjective reports of observers engaged in free-viewing. We asked whether these findings generalized to speeded performance. Experiment 1 showed that an important aspect of subjective perception--size-constancy scaling with perceived distance--also predicted the speed of pop-out visual search for cylinders viewed against a texture gradient. Experiment 2 showed that this finding could not be attributed to the local contrast between search items and the background texture. Experiment 3 assessed the relative contributions of 2 separable dimensions of texture gradients--perspective (radial spreading) and compression (foreshortening)--finding them to be independent in the more rapid search conditions (long target shorter distractors) but combined in the influence in the slower conditions (short target longer distractors).