Visual symmetry recognition by pigeons.

  title={Visual symmetry recognition by pigeons.},
  author={Juan D. Delius and Bernd Nowak},
  journal={Psychological research},
  volume={44 3},
Pigeons learned to discriminate a large number of bilateral symmetric and asymmetric visual patterns successively projected on the pecking-key of an operant conditioning chamber. Responses to the positive stimuli were reinforced according to a variable interval schedule. Once acquisition was complete generalization trials, involving sets of new stimuli, were instituted under extinction. The birds classified these novel test stimuli with high accuracy throughout, according to their symmetry or… CONTINUE READING