Effects of attention on visual perception are investigated by means of analysis of visual evoked potentials that reflect visual information processing in brain. For the purpose, an experiment is carried out on two experimental conditions. The first condition requires subjects to watch visual stimuli that are presented to them repeatedly, and the second requires them to do auditory tasks while watching visual stimuli. Results of the experiment show that response quantity of visual information processing is diminished when auditory tasks that attract subject's attention to hearing are imposed on them, even if they see visual stimuli using their central vision.
