THE DETERMINATION OF DIRECTION IN LANDMARK-BASED SPATIAL SEARCH IN PIGEONS - A FURTHER TEST OF THE VECTOR SUM MODEL

In four experiments, pigeons were trained to find hidden food at a constant location with respect to one or two arrays of landmarks. On crucial tests, the birds were presented with conflicting cues associated with two different directions, which were 90 degrees apart from the center of the search space at the same radial distance. The direction-averaging model predicts that the radial distance of search should not change on these tests, compared with radial distance of search on control tests without conflicting cues. The vector-averaging (vector sum) model predicts that when pigeons average the two conflicting cues, the radial distance of search should be shorter. Results support the direction-averaging model and suggest that distance and direction are independently computed in landmark-based search. Multiple sources are averaged by pigeons in determining direction.