It has long been an aim of computer scientists to develop software that can work out how a person is feeling. Are you happy or sad, frustrated or lonely? If the software can tell then it can adapt to you moods, changing its behaviour or offering advice. Suresh Neethirajan from Wageningen University in the Netherlands has gone step further. He has developed a program that detects the emotions of farm animals.
Working out how someone is feeling is called “Sentiment Analysis” and there are lots of ways computer scientists have tried to do it. One way is based on looking at the words people speak or write. The way people speak, such as the tone of voice also gives information about emotions. Another way is based on our facial expressions and body language. A simple version of sentiment analysis involves working out whether someone is feeling a positive emotion (like being happy or excited) versus a negative emotions (such as being sad or angry) rather than trying to determine the precise emotion.
Applications range from deciding how a person might vote to predicting what they might buy. A more futuristic use is to help medics make healthcare decisions. When the patient says they are aren’t feeling too bad, are they actually fine or are they just being stoical, for example? And how much pain or stress are they actually suffering?
But why would you want to know the emotions of animals? One really important application is to know when an animal is, or is not, in distress. Knowing that can help a farmer look after that animal better, but also work out the best way to better look after animals more generally. It might help farmers design nicer living conditions, but also work out more humane ways to slaughter animals that involves the least suffering. Avoiding cruel conditions is reason on its own, but with happy farm animals you might also improve the yield of milk, quality of meat or how many offspring animals have in their lifetime. A farmer certainly shouldn’t want their animals to be so upset they start to self harm, which can be a problem when animals are kept in poor conditions. Not only is it cruel it can lead to infections which costs money to treat. It also spreads resistance to antibiotics. Having accurate ways to quickly and remotely detect how animals are feeling would be a big step forward for animal welfare.
But how to do it? While some scientists are actually working on understanding animal language, recognising body language is an easier first step to understand animal emotions. A lot is actually known about animal expressions and body language, and what they mean. If a dog is wagging its tail, then it is happy, for example. Suresh focussed on facial expressions in cows and pigs. What kind of expressions do they have? Cows, for example, are likely to be relaxed if their eyes are half-closed, and their ears are backwards or hung-down. If you can see the whites of their eyes, on the other hand then they are probably stressed. Pigs that are moving their ears around very quickly, by contrast, are likely to be stressed. If their ears are hanging and flipping in the direction of their eyes, though, then they are in a much more neutral state.
There are lots of steps to go through in creating a system to recognise emotions. The first for Suresh was to collect lots of pictures of cows and pigs from different farms. He collected almost 4000 images from farms in Canada, the USA and India. Each image was labelled by human experts according to whether it showed a positive, neutral and negative emotional state of the animal, based on what was already known about how animal expressions link to their emotions.
Sophisticated image processing software was then used to automatically pick out the animals’ faces as well as locate the individual features, such as eyes and ears. The orientation and other properties of those facial features, such as whether ears were hanging down or up is also determined. This processed data is then fed into a machine learning system to train it on this data. The fact that it was labelled meant the program knew what a human judged the different expressions to mean in terms of emotions, and so could then work out how patterns in the data that represented each animal state.
Once trained the system was then given new images without the labels to judge how accurate it was. It made a judgement and this was compared to the human judgement of the state. Human and machine agreed 86% of the time. More work is needed before such a system could be used on farms but it opens the possibility of using video cameras around a farm to raise the alarm when animals are suffering, for example.
Machine learning is helping humans in lots of ways. With systems like this machine learning could soon be helping animals live better lives too.
– Paul Curzon, Queen Mary University of London, Spring 2021