Abstract

Uniform connectedness (UC; Palmer & Rock, 1994) means that a region with a uniform stimulus quality like color, texture, etc. is processed as a single unit. This study was intended to investigate the effect of uniform connectedness on the accurate identification of objects by manipulating the color uniformity of common objects such as wrenches or rings. In experiment 1, those colors of either upper or lower part were either the same or different, or a short bar connecting the two wrench's heads had a different color. Participants were asked to report the identity of target indicated by post-cue, briefly exposed on the threshold of identification. In the result, experiment 1 could not find the effect of UC, rather the negative repetition effect(i.e., NRE). Experiment 2 asked them to report the whole configuration of the wrench, and found neither UC effect nor NRE, both in UC condition and elements connectedness (i.e., EC) condition. Experiment 3 contrasted UC and EC condition in colors of left half and right half of the same ring, the task was to detect and report the identity of a ring according to the arrangements of small slits. In the result, UC effect was not observed and rather NRE was observed. Since NREs obseved in the UC conditions of experiments 1 & 3 were hard to explain using UC hypothesis, generally, the results of this study were interpreted to reject the hypothesis of UC.