Differences in duration of eye fixation for conditions in a numerical stroop-effect experiment.

Durations of eye fixation were recorded for a numerical Stroop effect experiment. Participants (6 men, 19 women; M age=22 yr.) reported the number of characters present in sequences of variable length (2 to 5 characters) while attempting to ignore the identity of the character. Three conditions were included: congruent (the number of characters and the numeral were matched, e.g., responding "two" to 22), incongruent (the number of characters and the numeral were mismatched, e.g., responding "two" to 55), and control (baseline of stimuli made up of "X"s, e.g., responding "two" to XX). Comparisons among the three conditions produced the longest response times and average durations of fixation for the incongruent condition. The shortest response times and average durations of fixation were obtained for the congruent condition.