Abstract

Two experiments were performed to compare the powers of the two alternative explanations, the simple cell-like mechanism and the symbolic processing mechanism, for the perception of the Glass pattern. The first experiment tested the effect of size difference between the two pairwise elements in the Glass pattern. The Result shows that the structure of the Glass pattern persists untill the size of one of the pairwise dot elements is enlarged up to 0.14˚×0.14˚ from its original size of 0.03˚×0.05˚ but disappears beyond that range. This range coincides with the upper limit in the size dimension of the simple cells found by Hubel & Wiesel(1968) in the monkey striate cortex, which suggests that the simple cell-like mechanism may be responsible for the perception of Glass pattern. While the second experiment tested the effectiveness of color information as a relevant stimulus property in the perception of the Glass pattern and the result show that although color information might he a relevant stimulus property, its effect is so weak that the effect may readily disappear when the signs of luminance contrast are different. Such a weak effect of the same or similar color implies the symbolic processing mechanism based on the similarity between the two pairwise dot elements may be inadequate for explaining the perception of Glass pattern and the results could be more adequately explained by the recent physiological research findings reporting the low resolution power of the channel responsible for color information processing. In conclusion, the results of this study imply that the perception of Glass pattern could be more adequately explained by the simple cell-like mechanism rather than the symbolic processing mechanism.