Exposure Time Mediates Perceptual Global Advantage with a Divided-Attention Paradigm

The effects of exposure duration of stimulus on perceptual global precedence were examined using a divided-attention paradigm and a normal/mirror judgment task. In the experiment, stimuli were presented at two exposure durations (unlimited and 80 ms). Subjects had to decide whether or not a normal letter appeared at either level of a compound stimulus. The results showed when the exposure time was limited as 80 ms, the subjects responded faster to global level of compound stimulus than to local level; when the exposure time was unlimited, the subjects´ response to global level of compound stimulus and to local level was of no difference. Our findings were discussed in terms of the mechanism of perceptual global advantage.