The purpose of the present study was to determine the effects of continuous white noise on visual target-detection performance. The variables manipulated were noise-intensity level, display-difficulty level, and target location. Four noise levels were utilized: 0, 80, 90, and 100 db. The 0-db. level served as the control condition. Display difficulty was defined in terms of the number of nontarget, or background, display elements. Three levels of difficulty were used: 8, 16, and 32 background letter characters. The target locations examined were the central and peripheral regions of the visual display. Twenty subjects were tested under all conditions. Both detection time and detection error were recorded. The results indicated that noise-intensity and display-difficulty level were significantly interrelated with respect to detection speed but not to detection error.
Visual target detection is not impaired in dyslexic readers
