Abstract
Psychophysical evidence suggests that the perception of surface properties such as color and texture is spatially regulated by, or filled-in from, signals at boundaries. I here show temporal filling-in with a new illusion in which a gradual change in visual features is frozen if caught by a surface. When a Kanizsa-type subjective figure was briefly presented (50–300 msec) on a uniform background of gradually changing color, the color inside the figure appeared to stop changing in time and to be different from the background color. When a drifting grating was used as the background, the grating inside the figure was perceived stationary and to have a lower spatial frequency than the background. Mere abrupt changes, e.g., luminance flash, were not sufficient to produce the illusion, suggesting a critical involvement of surface / object representations. These results were interpreted as indicating that the temporal-window for averaging, or filling-in, of surface feature representations is enlarged by onset / offset of the figure. This illusion can be considered as an important tool for understanding how the visual system binds features from continuous and dynamic image inputs, in the process of the filling-in both in space and time.