Baseline Performance with Separate Display Types

We examined the succeeding 30 sessions of training to see if any and what types of display type differences might emerge following acquisition. The results below show that the contrasting nature of the four display types did begin to have effects on the birds= choice performance once the task was learned. These steady-state differences most likely reflect the perceptual differences that existed among the display types. For instance, the local differences present in the feature displays did make a slight contribution to the birds= same-different judgements of this display type. In comparison to the texture displays, the feature displays supported slightly higher levels of different responding and lower levels of same responding. Given their otherwise identical global organization, this relative trade-off between same and different responses suggests that the local differences in the feature displays were not being entirely ignored. Despite this, the high level of accuracy with this display type verifies the spatially global nature of the discrimination learned by the pigeons. This point is similarly made by the high accuracy with the object display type as well.