Motion as a Natural Category for Pigeons: Generalization and a Feature‐positive Effect

Abstract

Three groups of pigeons were trained with a modified discriminative autoshaping procedure to discriminate video images of other pigeons on the basis of movement. Birds of all groups were shown the same video images of other pigeons, which were either moving or still. The group to whom food was presented only after moving images learned the discrimination very quickly. A second group, to whom food was given only after still images, and a pseudocategory group, to whom food was presented after arbitrarily chosen stimuli, showed no evidence of discrimination during acquisition training. Extinction conditions led to clear differences in peck rates to moving and still images in the second group but not in the pseudocategory group. The result is related to the feature-positive effect. Generalization tests showed that the discrimination performance was based on visual features of the stimuli but was invariant against changes of size, perspective, brightness, and color. Furthermore, discrimination was maintained when novel images of pigeons under different viewing angles and seven other types of motion categories were presented. It is argued that the discrimination is based not on a common motion feature but on motion concepts or high-order generalization across motion categories.

Successive two-item same-different discrimination and concept learning by pigeons

“…As such, could the pigeons have been simply seeing the videos as static displays? Dittrich and Lea (1993) found that pigeons can easily discriminate between static pictures and dynamic videos of similar content, so it is likely they were doing so here. Further, the reduced peck rates to the videos and the gradual improvement with experience each suggest that the videos were seen as fundamentally different from the static displays.…”

Recognition of moving video images of conspecifics by pigeons: Effects of individuals, static and dynamic motion cues, and movement

“…The discrimination eventually transferred fairly weil to the new stimuli in Test 2. Dittrich and Lea (1993) found that pigeons could respond discriminatively to moving and static video images ofobjects, including pigeons, humans, other animals, parts of a tree, and computer-generated geometrical shapes. They interpreted this as the formation ofa "motion" concept by pigeons.…”

Writing and overwriting short-term memory

“…Labels facilitate shape recognition by calling attention to distinguishing features (Daniel & Ellis, 1972). If the distinguishing element is the presence of a feature, animals naturally learn to attend to it, and discriminations are swift and robust; if the distinguishing element is the absence of a feature, attention lacks focus, and discrimination is labored and fragile (Dittrich & Lea, 1993;Hearst, 1991), as are attend-toeverything strategies in general.…”