Cats can associate sounds and images, a basic precursor of language
In the age-old debate of cats versus dogs, cats just scored a point. Housecats, it turns out, can quickly learn to associate words and pictures, similar to the way human babies and other animals, including dogs, can. The findings appear in a recent study published in Scientific Reports. What this means for cats' grasp of language remains a matter of some debate, however.
“While there has been much research on dogs’ understanding of human language, research on cats has been limited,” says lead author Saho Takagi, a comparative cognitive scientist at Azabu University in Japan. In studies testing dog language comprehension, the pups are often taught the names of toys and then asked to retrieve them. “Since cats rarely fetch, that method couldn't be used,” she says.
Instead, this study took a screen-based approach. Cats in private homes and cat cafes lounged in front of laptops that displayed two alternating animations: a cartoon sun and a cartoon spinning unicorn. The cats heard a specific made-up and meaningless utterance (either “parumo” or “keraru”) every time they saw an animation. Cameras set up around the monitor recorded how long each cat gazed at the screen.
After habituating the cats to associate certain images with certain sounds, the researchers switched things up. Suddenly, when the image of the unicorn appeared on screen, the opposite sound played. “We then examined whether the cats noticed the switch by measuring whether their looking time increased,” Takagi says. Indeed, the cats gazed at the laptop screen significantly longer when the animation didn’t match its expected sound, suggesting that they were confused.
A cat intently watches a monitor during a switch trial in which researchers presented a combination of auditory and visual stimuli that differs from its training. Image credit: Saho Takagi.
Learning to connect words to people, places, and things is a huge part of language acquisition, notes Brittany Florkiewicz, a comparative and evolutionary psychologist at Lyon College in Arkansas. “It seems like cats are really able to learn associations between sounds and external stimuli really quickly,” she says.
What’s more, the cats in this study made the associations without any kind of reward incentive, such as a treat, Florkiewicz says. That suggests the cats were independently motivated to associate novel images with sounds. Cats don’t have the same urge to please that dogs do, so it was essential to develop an experimental setup that was independent of social motivation, she says. Such a paradigm may not only shed light on cats, but perhaps on cognition in other species that are less socially motivated than dogs.
One clear next question, Florkiewicz says, is whether cats actually understand the meaning of words to some degree. That would mean not only associating sounds and images together, but also applying that knowledge in appropriate contexts. “At a basic level, this study shows rapid associative learning,” she says.
However, the study may conflate concepts of language, reference (the meaning of an utterance), and association, according to comparative psychologist Irene Pepperberg, a professor at Boston University in Massachusetts, who’s known for her studies of cognition and symbolic reference in parrots. Pepperberg acknowledges that making a paired association between one sound and one object is the way children begin to learn “what eventually becomes language.” But that falls far short of the sophistication of connections required for language. “Most cats I know have paired the sound of an electric can opener with food and show interest when any can is opened,” she notes, suggesting that the authors may have overinterpreted their findings. “The implications for language evolution are minimal.” Even so, Pepperberg hopes that the study will generate a lot of interest and that other researchers will replicate and expand on the experiment to understand more about how cats learn.
“Dogs are renowned for their ability to communicate with people—for example, knowing their name, following our gaze,” says evolutionary biologist Jonathan Losos at Washington University in St. Louis, Missouri. “Cats are more subtle, but we now know they have a lot of these abilities as well.” One next question he sees is whether the ability to associate sounds with images evolved before or after domestication. The modern-day housecat was domesticated from the North African wildcat sometime between 10,000 and 3,500 years ago, Losos says, based on the dates of archaeological evidence from Cyprus and Egypt. Studies in extant North African wildcats could, in principle, shed some light on whether the trait evolved before or after domestication, Losos says.
Florkiewicz notes that follow-up gaze studies could test not only associations between images and vocalizations, but between other types of communication in cats, such as facial expressions and gestures.
Takagi remains interested in “exploring how much of human language cats understand.” She adds that experiments to test whether they can distinguish between Japanese and English are on the horizon.
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