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Discrimination of relative numerosity by pigeons


In three experiments, pigeons were trained to discriminate between uniform arrays of two elements that differed in color, form, or size. They were then tested with arrays that contained different proportions of the two elements on these dimensions. In all cases, orderly discrimination gradients reflected these proportions. The discrimination readily transferred to new arrays with similar stimuli, but with different total numbers of elements. In Experiment 4, the pigeons were taught to discriminate between two groups of categorical stimuli: pictures of birds and pictures of flowers. A test with different proportions of each again produced a gradient based on relative numerosity. Experiment 5 demonstrated transfer of stimulus control on the numerosity dimension when pigeons were trained with one set of instances from two categories, and then were tested with new instances from the same categories.


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Correspondence to W. K. Honig.

Additional information

This research was supported by Grant AO-102 from the Natural Sciences and Engineering Research Council of Canada.

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Honig, W.K., Stewart, K.E. Discrimination of relative numerosity by pigeons. Animal Learning & Behavior 17, 134–146 (1989).

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  • Stimulus Control
  • Discrimination Training
  • Transfer Test
  • Discrimination Ratio
  • Uniform Array