This experiment is based on the following paper:
Treisman, A., & Gelade, G. (1980). A feature-integration theory of attention. Cognitive Psychology, 12, 97-136. Reprinted by permission of Academic Press.
Treisman proposed new theory of attention, in which separate features such as color and direction of movement are perceived first, and later integrated into whole objects. This experiment explores one portion of this theory related to visual search.
If, as we assume, simple features can be detected in parallel with no attention limits, the search for targets defined by such features (e.g., red, or vertical) should be little affected by variations in the number of distractors in the display. …In contrast, we assume that focal attention is necessary for the detection of targets that are defined by a conjunction of properties (e.g., a vertical red line in a background of horizontal red and vertical green lines). Such targets should therefore be found only after a serial scan of varying numbers of distractors. (p.99)
Her model also suggested that given sufficient practice, such a conjunction of properties may be redefined as a single feature, thus allowing the use of the more efficient parallel search.
The full text describing the experiment is available here.
The experiments are available below.
treisman_gelade_win.zip (78.1 KB)
treisman_gelade_mac.zip (117 KB)