[Effects of dominance between global and local processing on individual differences of lightness filling-in]

This study investigated the individual differences of lightness filling-in on illusory contour figures with regard to the attention to figures; namely, to which information of hierarchical figures, the global information or the local information, subjects tended to allocate their attention. Subjects participated in a preliminary experiment to divide into a global group and a local group. The global group consisted of ten subjects who had a tendency to allocate their attention to the global configuration of hierarchical figures and the local group consisted of ten subjects who had a tendency to allocate their attention to the form of local elements of hierarchical figures. Both groups observed the Kanizsa squares and judged the lightness of the test field. The results showed that the local group significantly filled in greater lightness in the test field than the global group did. It is suggested that how subjects allocate attention to figures is one factor in individual differences of lightness filling-in and that lightness filling-in depends on top-down processing.