PIGEONS ARE SENSITIVE TO THE SPATIAL-ORGANIZATION OF COMPLEX VISUAL-STIMULI

Two experiments investigated the role of spatial organization in the d iscrimination and generalization of complex visual stimuli by pigeons. In Experiment 1, after pigeons had been trained to discriminate line drawings of four objects, they were tested with novel pictures in whic h the same component parts of the objects were spatially rearranged. T he spatially scrambled pictures led to a dramatic drop in recognition accuracy, but responding remained above chance. In Experiment 2, pigeo ns reached a high level of discriminative performance when required to choose among four different spatial arrangements of the same object p arts. These results confirm Cerella's (1980) conclusion that pigeons d iscriminate the component parts of complex visual stimuli, but, unless it is assumed that the scrambling deleted or created emergent feature s, the results disconfirm his conclusion that spatial organization pla ys no role in pigeons' picture perception.