Dogs have an excellent smell, which is generally known. But, how do they "see" in their heads what that scent is, can they really think of a picture? Up to now, science has not been very concerned about this. But this week a study was published in the Journal of Comparative Psychology, in which scientists at the University of Jena provide evidence that dogs do indeed make a "mental representation" of the object they smell. Or, in other words, they know what they are going to see when they have reached the end of the scenttrail.
Dr. Juliane Bräuer did tests with a total of 48 dogs, including 25 police detection dogs or rescue dogs of rescue teams. The other 23 were ordinary homedogs without any form of training. First of all the dogs did a pre-test, in which the dogs could indicate their two favorite toys, from an arsenal of several toys. In the final test set-up, the dog ran four scent traces made with one of the two toys. At the end of the track, the dog would found either the toy with which the track was made, or another toy. All dogs were filmed during the tests.
The researcher assumed that the dog, if he found the "unexpected" toy, also would show that in his behavior. And that turned out to be true, quite a few of the dogs that found the "surprise toy" showed hesitation, and continued to search for the toy they expected based on the scent. That was especially the case in the first few tests, when the dogs ran a trail more often the effect disappeared, possibly because after finding the object they always got something tasty as a reward, or because there was still some smell of the expected toy hanging in the room, despite cleaning after each run.
Nevertheless, according to Dr. Bräuer, the first results show that dogs indeed form a picture in the brain of what they smell. And so really have an expectation of what they will find. Another discovery in the research was that the police dogs in the first rounds found the object indeed, as expected with their training, the fastest, but that after three or four runs the house dogs were just as fast as the police dogs.