Size scaling and spatial factors in visual attention

This study investigates the effect of the visibility of near and far letter distractors tors on target processing by scaling the size of the distracter letters to compensate for changes in resolution across the visual field. In Experiment 1, scaled and unsealed distractors were presented at varied stimulus onset asynchronies. Results showed that scaling the size of distractor letters in relation to their distance from the target was effective in producing strong compatibility effects. Scaled distractors presented prior to, or simultaneously with, the target were found to interfere with target processing whether they were near or far from the target. Experiment 2 used scaled distracters and varied the presentation location and the amount of time for processing prior to the presentation of the target. Compatibility effects were found to vary by location and by the exposure duration of the distracter. The finding of distance effects at far locations supports a space-based visual-attention mechanism with a wide attention beam (Steinman, Steinman, & Lehmkuhle, 1995).