A research study has discovered that areas of a dog’s brain react when shown two dimensional images of other dogs or human faces. The researchers also studied the reaction when dogs were shown images of inanimate objects. There was little response when compared to reactions to the first images.
Dogs are highly social animals and have been domesticated for a long time. They have learned to live with humans and to interact with them. Scientists have already researched the fact that dogs can process facial information, but they wanted to understand which neurones were directing the behaviour. If the dogs were responding to a human face because of a food reward, then it was to be expected that the areas of the brain corresponding to rewards would light up. Previous studies have confirmed this finding. However in monkeys and humans – two highly social creatures, specific areas of the brain will react when a face is seen. Researchers wanted to see if the same were true for dogs, which are also social animals.
The dogs used in the experiment needed to undergo specialised training. They had to learn to sit still in an fMRI machine, on an adapted individual chin rest so that head movement could be minimised. They had to learn to cope with a noisy environment because the machine is so loud, and they also had to sit still and look at a screen. Eight dogs began the training for the experiment, but two found it too difficult to sit still for long enough to produce valid results, so they were discarded. The dogs were pets and some were ex-service dogs. They had all undergone training for a previous experiment and all of them were able to sit in the machine and focus on an image for at least 30 seconds.
Although the sample for the study was small, it brought clear results: an area of the dogs’ temporal lobes activated when the dog was looking at a human face or another dog face. The scientists named this the ‘dog face area’. Looking at images of inanimate objects did not bring a reaction. These results suggested that the ability to distinguish faces from other objects had been programmed into the brain, possibly indicating that it was an important function for such social animals to be able to do.
Some disadvantages of this experiment were the small sample size and the fact that the dogs were conscious and therefore were moving around a little, however the scientists on this study are confident that the results can be relied on and taken forward to future studies.
Research available to read online:
Dilks, D.D., et al., Awake fMRI reveals a specialized region in dog temporal cortex for face processing; PeerJ 3:e1115