The negative repetition effect (NRE) refers to a poorer perception of the target in noise-same-as-target than in noise-alternative-target displays. Using the parenthesis as target and noise that are either identical or different in orientation, we tested predictions derived from a feature-specific inhibition model (Bjork & Murray, 1977) that explains the NRE as arising from inhibitory interactions among channels handling identical inputs. Contrary to our expectation of evidence for orientation-specific inhibition, a positive repetition effect (PRE) was observed. We also found a PRE for the dimension target sets whose stimuli differ only in orientation and an NRE for the feature target sets whose stimuli differ in the number of elements. Further experiments that systematically varied relationships between alternative targets indicate that these basic findings, termed the stimulus attributes effects, do not arise from pattern masking, perceptual strategies, or response bias.