Differences in the luminance of the first and second displays affects visible persistence in opposite ways

Visible persistence was measured using a two-frame temporal integration paradigm. Most such studies match the brightness of the two frames, and find that equal increases in the brightness of the frames impairs performance on the task. This suggests that increases in frame brightness decrease the duration of visible persistence. Little is known about what happens when the frames differ in brightness. In this study, the luminance intensities of the first and second frames were set at five different intensity levels in a factorial arrangement. Increasing the intensity of the first frame improved performance, whereas increasing the intensity of the second frame impaired performance. These results suggest, contrary to the findings with brightness-matched frames, that increasing the intensity of one frame increases the duration of visible persistence of that frame. A mathematical model supports this conclusion.