GROUP, ASSIMILATION, AND INCREASE IN VISIBILITY ASSOCIATION WITHOUT ADIFFERENCE IN FEATURES

There is evidence that one group is associated with assimilation among its parts and an increase in visibility (IV) of at least one of its p arts: the 1group-assimilation-IV position. The present research suppor ts this position using physically identical stimuli, hence eliminating differences in features. This was accomplished by comparing the effec ts of large and small backgrounds on responding to physically identica l stimuli that appeared on these backgrounds. Compared to the small ba ckground, the large background produced a stronger two-line group acco rding to a closure measure of grouping, more assimilation between two lines according to a same-different measure of perceived similarity, a nd a greater IV of one of two lines according to context+target versus context relative to target versus background discriminations. The lar ge background was much larger than the two small lines, suggesting tha t it functioned as an anchor.