Recognition of asymmetric alterations to pictures of cats and geometric shapes: effects of method and type of alteration.

The present study investigated the effects of the method of alteration (introduction or restoration) and the effects of type of alteration (addition or deletion) on recognition of animate objects and geometric figures. Stimuli were pictures in which a feature was added to an original, deleted, or unchanged. After viewing a series of pictures, participants were tested for recognition. Results showed participants rejected pictures with deleted features more accurately than those with added features even when stimuli were made by both methods of alteration. An effect of type of alteration was observed for introduction of alterations into both original pictures of cats and of geometric figures. These results differed from previous studies. It is suggested that the effects of method of alteration and type of alteration on recognition of pictures of animate objects is different from those of inanimate objects and that the effects of method of alteration on recognition should be considered an important variable in these studies of recognition.