November 23, 2012
For Dogs, Learning To Associate Words With Objects Is A Different Process
[ Watch the Video: Familiarization with Word ]
April Flowers for redOrbit.com - Your Universe Online
Human children between the ages of two and three typically learn to associate words with the shapes of objects, rather than their size or texture. If you teach a toddler what a "ball" is and then present them with an array of other objects similar in shape, size, or textures, the child will choose a similarly shaped object as "ball" rather than one of similar texture or size.
Dogs can learn to associate words with categories of objects, such as "toy," previous studies have shown. But it was still unknown whether their learning process was the same as that of humans.
In this current study, published in the journal PLOS ONE, the research team used a five year old border collie named Gable. They presented Gable with similar choices to see if this "shape bias" exists in dogs as well as humans. After a brief training period, Gable learned to associate the name of an object with its size. Gable would then identify objects of similar size by the same name. Longer periods of exposure to both names and objects allowed Gable to learn to associate a word to objects of similar textures, but not object of similar shapes.
The authors claim that the results suggest dogs (or at least Gable) process and associate words with objects in qualitatively different ways than humans. The way dogs and humans perceive shape, texture and size might be due to differences in how evolutionary history has shaped each species senses.
The bottom line according to the researchers: although your dog might bring back the right object when you command, "fetch the ball," he probably thinks of the object in very different ways than you do.
"Where shape matters for us, size or texture matters more for your dog. This study shows for the first time that there is a qualitative difference in word comprehension in the dog compared to word comprehension in humans."
Gable isn't an anomaly, however. Last year, ABC News reported on a border collie named Chaser whom they touted as "the world's smartest dog."
Chaser's owner, John Pilley, spends four to five hours a day working with Chaser on her vocabulary. Pilley is an 82-year-old retired psychology professor in Spartanburg, S.C., and he has trained Chaser to have a vocabulary of over 1,000 words and simple phrases using objects.
Chaser has quite a collection: 800 stuffed animals, 116 balls, 26 "Frisbees," and other assorted items. Each item has its own distinct name. Chaser can identify each object by its own name. To test this, astrophysicist and PBS host Neil deGrasse Tyson brought along a new object which he named "Darwin."
A random sampling of toys was selected and placed in a different room from Chaser and the humans. As Tyson called out names, Chaser would go into the other room, select the correct toy and bring it back. "Darwin," which Chaser had never seen before, was placed in the room and Chaser located it amid the other toys.
Pilley has taught Chaser verbs as well, including "find," "paw," and "nose." She will perform each action, as requested, on any of the 1,000 objects.
"The flexibility we see in dogs seems to be very similar to what you see in young children at a very important age in their development," said animal researcher Brian Hare at the Duke Institute for Brain Sciences.
Hare studies chimps and bonobos, among other primates. Chimps and bonobos have shown the ability to learn sign language and solve sophisticated problems. Compared with Chaser, however, their ability to learn is slow.
Hare attributes this to social intelligence. Unlike dogs, chimps don't pay attention to their trainers. Dogs are always sensitive to their human masters.
"When I see my dog, my dog wants me to be around. He wants me to be his social partner. He actually needs me, whereas a bonobo and a chimpanzee -- they don't need me," Hare said.
Researchers hypothesize that domestication, literally tens of thousands of years of association with humans, has allowed dogs to develop a humanlike social learning ability. Hare and other primate researchers are starting to set up dog research labs to test this theory.