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A Scientific Catalog of Horses’ Facial Expressions

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University of Sussex researchers are giving a new meaning to the term “horse-faced.” A new way of classifying horse facial expressions laid out in a study published in the journal PLOS ONE is designed to standardize research on equine psychology and cognition, eventually helping even laypeople understand what might be running through their horse’s brain. 

The systematic model, EquiFACS (a human version, Facial Action Coding Systems, has been around since 1978), is a comprehensive list of all the different facial expressions domestic horses are capable of making. The scientists dissected a horse head to better understand its musculature, and collected 15 hours of video footage of 86 horses interacting in a variety of situations to create a kind of encyclopedia of possible equine facial expressions. 

See some examples in the delightfully horsey videos:

Some of the facial expressions horses made were similar to humans, even using analogous facial muscles (like pressing the lips together or stretching the mouth). However, the researchers didn’t code what the facial expressions meant in terms of horse behavior, just what they looked like, so it’s impossible to say how the horse expressions might differ from similar human expressions in practical use. 

Horses are social herd animals that primarily experience the world through sight, making facial expressions and body posture especially important communication methods. The study confirms that horses have a wide range of facial expressions at their disposal. Humans display 27 of these Action Units, but horses have 17, a fair number compared to chimps (13) and dogs (16). If you make a face at a horse, chances are he can make it back at you. 

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Animals
Goldfish Can Get Depressed, Too
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Don’t believe what Pixar is trying to sell you: Fish are not exactly brimming with personality. In aquariums, they tend to swim in circles, sucking up fragments of food and ducking around miniature treasure chests. To a layperson, fish don’t appear to possess concepts of happy, or sad, or anything in between—they just seem to exist.

This, researchers say, is not quite accurate. Speaking with The New York Times, Julian Pittman, a professor at the Department of Biological and Environmental Sciences at Troy University, says that fish not only suffer from depression, they can be easily diagnosed. Zebrafish dropped into a new tank who linger at the bottom are probably sad; those who enthusiastically explore the upper half are not.

In Pittman’s studies, fish depression can be induced by getting them “drunk” on ethanol, then cutting off the supply, resulting in withdrawal. These fish mope around the tank floor until they’re given antidepressants, at which point they begin happily swimming near the surface again.

It’s impossible to correlate fish depression with that of a human, but Pittman believes the symptoms in fish—losing interest in exploring and eating—makes them viable candidates for exploring neuroscience and perhaps drawing conclusions that will be beneficial in the land-dwelling population.

In the meantime, you can help ward off fish blues by keeping them busy—having obstacles to swim through and intriguing areas of a tank to explore. Just like humans, staying active and engaged can boost their mental health.

[h/t The New York Times]

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Pigeons Are Secretly Brilliant Birds That Understand Space and Time, Study Finds
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Of all the birds in the world, the pigeon draws the most ire. Despite their reputation as brainless “rats with wings,” though, they’re actually pretty brilliant (and beautiful) animals. A new study adds more evidence that the family of birds known as pigeons are some of the smartest birds around, as Quartz alerts us.

In addition to being able to distinguish English vocabulary from nonsense words, spot cancer, and tell a Monet from a Picasso, pigeons can understand abstract concepts like space and time, according to the new study published in Current Biology. Their brains just do it in a slightly different way than humans’ do.

Researchers at the University of Iowa set up an experiment where they showed pigeons a computer screen featuring a static horizontal line. The birds were supposed to evaluate the length of the line (either 6 centimeters or 24 centimeters) or the amount of time they saw it (either 2 or 8 seconds). The birds perceived "the longer lines to have longer duration, and lines longer in duration to also be longer in length," according to a press release. This suggests that the concepts are processed in the same region of the brain—as they are in the brains of humans and other primates.

But that abstract thinking doesn’t occur in the same way in bird brains as it does in ours. In humans, perceiving space and time is linked to a region of the brain called the parietal cortex, which the pigeon brains lack entirely. So their brains have to have some other way of processing the concepts.

The study didn’t determine how, exactly, pigeons achieve this cognitive feat, but it’s clear that some other aspect of the central nervous system must be controlling it. That also opens up the possibility that other non-mammal animals can perceive space and time, too, expanding how we think of other animals’ cognitive capabilities.

[h/t Quartz]

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