Abstract

The faded image of a high-contrast stabilized target reappears if a brief step increment of uniform luminance is added to the target, but the regenerated apparent image is reported to be of the opposite phase of the target. Using a matching technique, we measured the contrast of the apparent image as a function of the magnitude of the uniform increment for several luminances and two contrasts of the adapting target. It increased linearly with the magnitude of the increment and was an exponential function of the adapting background luminance. When the increment was a fixed proportion of the adapting background, the apparent contrast was constant with respect to the background luminance. The shapes of the functions relating the uniform increment to the adapting back ground remained the same, but they were scaled when contrast was increased. These results indicate the presence of an adaptation process that multiplies the inverse sensitivity or gain image by the incremented target to produce an apparent phase reversal. They are consistent with a model in which gain is a decreasing function of target luminance.

© 1990 Optical Society of America