Can Horses Recognize Pictures?

摘要

The data reported here are the results of the first stage of an ongoing study that investigates the ability of horses (Equus caballus) to recognize photographs of three-dimensional (3D) objects and recognize objects previously seen only as photographs. Using a two-choice discrimination task, three horses were taught to select complex objects for up to three stimulus sets and color photographs for another two to three sets. Once a discrimination was acquired (19/20 consecutive correct responses; z = 4.02, α = .01, binomial test) and additional overlearning trials were run, the corresponding 2D or 3D raplicas were tested. The results of the first 20 trials for each situation showed that, for 13 of 15 sets, the horses responded significantly above chance and/or significantly higher on the transfer trials than on the original discriminations. On the original 15 discriminations, the horses scored below or at chance levels on all but four sets. Above chance performance on two of these four sets was most likely due to the fact that these were the first training stimuli-with the correct choice being the preferred stimulus. All subsequent positive stimuli were nonpreferred in preference tests. These results suggest that some horses are able to recognize photographs as objects as well as objects previously represented by pictures.