University of Alberta Dictionary of Cognitive Science: Feature Integration Theory

Search latency results, which revealed that some objects pop out but others do not, formed the basis for feature integration theory (Treisman, 1985, 1986, 1988; Treisman & Gelade, 1980; Treisman & Gormican, 1988; Treisman, Sykes & Gelade, 1977). Feature integration theory is a multi-stage account of visual cognition. In the first state, preattentive processors register the locations of a small set of primitive visual features on independent feature maps. These maps represent a small number of properties (e.g. orientation, color, contrast movement) that also appear to be transduced by early neural visual detectors (Livingstone & Hubel, 1988). If such a feature is unique to a display, then it will be the only active location in its feature map. This permits pop out to occur, because the location of the unique, primitive feature is preattentively available.

Unique combinations of features do not produce unique activity in a single feature map, and therefore cannot pop out. Instead, they require additional processing in order to be detected. First, attentional resources must be used to bring the various independent feature maps into register with respect to a master map of locations. This master map of locations will indicate what combinations of features coexist at each location in the map. Second, a “spotlight” of attention is used to scan the master map of locations in search of a unique object. Because this attentional spotlight can only process a portion of the master map at any given time, and because it must be scanned from location to location on the master map, it takes longer for unique combinations of features to be found. Furthermore, the search of the master map will become longer and longer as more of its locations are filled, explaining why the latency to detect unique feature combinations is affected by the number of distractors present.

References:

Livingstone, M., & Hubel, D. (1988). Segregation of form, color, movement and depth: Anatomy, physiology, and perception. Science, 240, 740-750.
Treisman, A. M. (1985). Preattentive processing in vision. Computer Vision, Graphics, and Image Processing, 31, 156-177.
Treisman, A. M. (1986). Features and objects in visual processing. Scientific American, 254, 114-124.
Treisman, A. M. (1988). Features and objects: The fourteenth Bartlett memorial lecture. Quarterly Journal of Experimental Psychology, 40A, 201-237.
Treisman, A. M., & Gelade, G. (1980). A feature integration theory of attention. Cognitive psychology, 12, 97-136.
Treisman, A. M., & Gormican, S. (1988). Feature analysis in early vision: Evidence from search asymmetries. Psychological Review, 95, 14-48.
Treisman, A. M., Sykes, M., & Gelade, G. (1977). Selective attention and stimulus integration. In S. Dornic (Ed.), Attention and Performance VI. Hillsdale, NJ: Lawrence Erlbaum Associates.

(Added September 2010)