In psychophysical and neurophysiological experiments, the subjects recognized images of two categories, "animals" and "objects." The images of the same categories differing from the target stimuli were used as the masking stimuli. We found that the efficacy of forward-masking depended on categorical similarity of the masking and target stimuli. The probability of a correct response was lower and the reaction time and its variance were higher when we used stimuli of the same category compared with presentation of stimuli of different categories. Categorical similarity of masking and target stimuli induced difficulties with response, which were accompanied by decreases in the amplitudes of the N2 and P3 components of the evoked potentials. These effects were more pronounced during recognition of animals compared to objects. The results are discussed from the point of view of negative priming and the distractor effect. © 2014 Pleiades Publishing, Inc.
