Motion as a natural category for pigeons: Generalization and a feature-positive effect.
Motion can work as a natural, easy-to-generalize cue for learning in animals.
01Research in Context
What this study did
Kennedy et al. (1993) worked with pigeons in a lab box. Birds saw short movie clips on a screen. Some clips showed motion. Others were still.
Food came only after motion clips. The team then tested new clips. They changed size, color, brightness, and camera angle. They wanted to see if the birds still chose motion.
What they found
The pigeons learned fast. They pecked when motion was on. They stayed quiet for still frames.
Even when the clips looked very different, the birds still picked motion. Motion acted like a natural category, the way “dog” or “tree” does for people.
How this fits with other research
Siegel (1971) first showed pigeons can tell real movement from fake movement. Kennedy et al. (1993) went further. They proved motion itself can be a category, not just a cue.
Luckett et al. (2002) built on this. They showed pigeons can later zoom in on speed or direction alone if the payoff changes. Motion is first one big group, then it can split into parts.
Lancioni et al. (2006) ran a similar go/no-go task but used a tricky “launching effect.” Birds learned slowly and used side cues, not the causal rule. The method looks alike, yet the learning is weaker when the rule is narrow.
Why it matters
Motion can be a powerful cue in your lessons. If you want a learner to notice “something is happening,” use moving images or objects first. Once the broad class is strong, you can shape finer skills like speed or direction. Test with new clips often to be sure the learner is really watching motion, not just color or size.
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02At a glance
03Original 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.
Journal of the experimental analysis of behavior, 1993 · doi:10.1901/jeab.1993.59-115