Figure 8.14: Stimuli that pop out or do not pop out These stimulus arrays are similar to those used by Treisman and Gormican (1988). In (a) the target stimulus (slanted green line) differs from the distractor stimuli in a primitive feature; it is the only slanted line in the array. Here the target pops out at you; you notice it immediately even if you aren’t looking for it. In (b) the target stimulus (slanted green line) does not differ from the distractors in a primitive feature; its greenness is matched by some distractors, and its slant is matched by other distractors. Rather, this target is distinct in the way its features are conjoined. It is the only line that is both green and slanted. This target does not pop out at you; you have to look for it to notice it.