The pigeon's discrimination of shape and location information

Two groups of pigeons (n = 4) were trained with 16 line drawings portraying a fixed shape and a variable shape. The four variable shapes (a wedge, a c one, a cylinder, and a handle) appeared to the left of, to the right of, ab ove, or below the fixed shape (a cube). Group Shape (S) was required to dis criminate the identity of the variable shape that was mated with the cube, whereas Group Location (L) was required to discriminate where the variable shape appeared relative to the cube. Three of the four pigeons in each grou p mastered their respective tasks. Later tests revealed that the two groups of pigeons had attended to different aspects of the shape pairs, even thou gh the visual stimuli and general procedures they had been given were the s ame. Group S had attended to the identity of the variable shape and had ign ored the identity and location of the cube, whereas Group L had attended to the configuration of the two shapes. The methods and stimuli could be usef ul in delineating the biological bases of shape and location perception.