Bridging attentional capture and control: Evidence from a partial report paradigm with color singletons

Despite a vast body of research, it remains unclear whether a singleton captures attention even if the singleton is of no relevance to the task. The present study addressed the question of how the presence of a color singleton influences the efficiency of target selection in a partial report experiment with poststimulus masks. Subjects reported the letters from a circular array of 6 letters and 0, 2, or 4 digits. All characters were white and encircled by a white outline. One twelfth of the presented letters and one twelfth of the presented digits were color singletons. A singleton differed from other characters only with respect to the color of the encircled local background. For both singleton and nonsingleton elements, the probability that an element showed a letter rather than a digit was 5/7. At most one singleton was presented in any given display. The probability distribution of the number of correctly reported letters was analyzed as a function of number of digits, singleton presence, and singleton type (target vs. distractor) at 7 exposure durations ranging from 10 to 200 ms. Also, the probability of reporting a presented letter was analyzed as a function of letter type (singleton letter, or letter presented in a display without any singleton, with a singleton digit, or with a singleton letter). The (preliminary) results showed virtually no effect of occurrence of singletons on subjects' mean scores. However, a singleton letter had a higher probability of being reported than a nonsingleton letter. This was also reflected by singleton weights when fitting the data by a mathematical model based on Bundesen's (1990) “theory of visual attention” (TVA).