As humans we use our faces to communicate and express feelings. Some facial expressions are understood to be universal, allowing us to interpret the basic intentions of any human regardless of culture or language. Unsurprisingly then, we also look at animals’ faces in an attempt to know their feelings. Yet we don’t actually know how animals use facial expressions. Can facial expressions give us an insight into an animal’s mind or their feelings? Are facial expressions consistent between individuals? Are they used for communication? These are the type of questions we can start to understand through studying facial expressions in animals. Dogs are a particularly interesting animal in which to study faces because their success as a species has depending on reading human expressions and communicating with us. Pet dogs cooperate with us to play games, working dogs cooperate to perform complex tasks like guiding the blind or partially sighted.
Scientists wishing to measure facial expressions in animals or humans will typically create a catalogue of different movements of the face and then record in which situations these movements occur. Such a catalogue might include, for example, a lift of the inner brow, a wrinkle of the nose and bulge of the cheek. There are problems with this approach when studying animals because humans are biased towards cataloguing facial movements which are similar to those shown in humans. Using sensor technology and mathematical models we can measure movements of the face directly. This means we aren’t reliant on humans to detect facial expressions. Both subtle and more extreme facial movements can be detected and the context in which these appear can be noted. Over time using such an approach it will be possible to use an algorithm to gain insight into whether a dog (or other animal) is in pain, is afraid or likely to become aggressive, even when the signs are very subtle.