In two experiments, subjects performed a luminance detection task under conditions of low arousal and high arousal. In the low arousal condition, subjects heard 7 dB(A) broadband noise, and in the high arousal condition they heard 1 dB(A) noise. Stimuli were presented on a cathode ray tube, and appeared at the center and along the perimeter of an imaginary circle. Two expectancy conditions were used: a central expectancy condition, in which most of the stimuli appeared at the center of the screen and a few appeared along the perimeter, and a peripheral condition in which the opposite was true. Subjects responded faster to central stimuli than peripheral stimuli; they also responded faster to expected stimuli than unexpected stimuli. Noise had no effect on the way in which subjects processed location or expectancy information . It was concluded that arousal has no effect on the breadth of attention in this task.