Object permanence in dogs: Invisible displacement in a rotation task

Dogs were tested for object permanence using an invisible displacement in which an object was hidden in one of two containers at either end of a beam and the beam was rotated. Consistent with earlier research, when the beam was rotated 180°, the dogs failed to find the object. However, when the beam was rotated only 90°, they were successful. Furthermore, when the dogs were led either 90° or 180° around the apparatus, they were also successful. In a control condition, when the dogs could not see the direction of the 90° rotation, they failed to find the object. The results suggest that the 180° rotation may produce an interfering context that can be reduced by rotating the apparatus only 90° or by changing the dogs' perspective. Once the conflict is eliminated, dogs show evidence of object permanence that includes invisibly displaced objects.