Perceptual organization and focused attention: the role of objects and proximity in visual processing.

The influence of the Gestalt grouping principles of similarity, closure, and proximity on the size of the response-compatibility effect was examined in a focused attention task. In three studies, subjects responded to a centrally located target and attempted to ignore adjacent distractors. The distractors, which served as targets on other trials, could be compatible, incompatible, or neutral with respect to the response of the target. In addition, the distractors and the target could be embedded in the same object, presented in the same color, presented on different objects, or presented in different colors. The typical response-compatibility effect (B. A. Eriksen & C. W. Eriksen, 1974) was found when the target and distractors were embedded in the same object or presented in the same color. Performance was poorer when the target was surrounded by response-incompatible distractors than when it was surrounded by response-compatible distractors. However, the response-compatibility effect was eliminated when the target and distractors were embedded in different objects, even when the distance between the items was less than .25 degrees of visual angle. Furthermore, the response-compatibility effect was of intermediate size when the distractors were not grouped strongly with the target or with neutral flankers. The results are discussed in terms of space- and object-based models of visual attention.