Brightness Comparison with Central and Peripheral Vision by Using a Dual-Task

Brightness comparison with central and peripheral vision was conducted to investigate the relation between brightness perception and attention. A dual-task was employed which consisted of a central vision task to detect a character with different luminance from others on RSVP (Rapid Serial Visual Presentation), and a brightness comparison task just after the former task. In brightness comparison, the luminance was 6cd/m2 for central stimulus and from 3 to 12 cd/m2 for the peripherals with 10 or 20 degrees eccentricity. SOA was 200 or 500 ms in the both task. As the results, the change of the perceived peripheral brightness with the luminance was larger (i.e., the perceived brightness was more affected by the luminance change of the stimulus), when the SOA was longer, the eccentricity was smaller and / or the subject was more experimented. The duration of the stimulus presentation was longer than the critical duration of the photoreceptors. SOA, eccentricity and skills generally change attention status. Therefore, the results suggest that the brightness was affected by attention in this experiment.