ABSTRACT
John Cerella's argument is that stimuli, like the "summer vacation" photographic slides used by R. J. Herrnstein and colleagues, are collages of particulate fragments for the pigeon. Even the most apparently sophisticated and human-like discrimination by pigeons represents a solution based on static local cues. The pigeons were insensitive to the arrangement of the entire original. Instead, performance depended on the presence of the component parts that were preserved within the thirds that were scrambled. The pigeon's task is to continue to attend to the original forms that signal the food schedule and respond appropriately. The effect of interest is whether the pattern of disruption of discriminative performance covaries with the systematic manipulation of characteristics of the distractor's presence. Both proximity and similarity of the distractor letters affected the pigeon's ability to respond on the basis of the target alone.
