"Unified Dog Theory 9: Understanding Pattern Recognition in Dogs."
Chaser Knows the Names of Over 1000 Toys: Pattern Recognition or Linguistic Ability?
Originally published in slightly different form on January 12, 2011 at PsychologyToday.com.
The Amazing Chaser
There are three interesting studies in the news right now. The first is about Chaser, a border collie who’s been rigorously trained to remember the names of all 1022 of her toys, and can differentiate between the verbs “to nose,” “to paw,” and “to take.” She learned to do this in a series of 4-hour sessions, taking place over a period of three years, using a ball as a reward for making a successful match between a word and a toy, or a word and an action.
Some in the media, and even in the scientific community, have touted Chaser’s abilities as evidence that she has a rudimentary capacity to understand human language, and that her linguistic abilities are on a par with those of a 3-year old child.
Most animals—dogs and humans included—process salient features of their environments by making internal representations of them. This is pretty simple stuff. We look at an object but our eyes don’t really see it, they just provide raw sensory data, which is translated by the visual circuitry in our brains into a representation, or mental image, of that object. Dogs are clearly able to do this, otherwise they wouldn’t be able to dream or catch Frisbees (or perhaps dream of catching Frisbees).
However, when get into the realm of what words “mean,” we’re entering the territory of representations of representations. This means that for Chaser’s abilities to rise to the level of a 3-year old child’s linguistic skills, she would have to be able to understand words in a more abstract fashion, not just as verbal cues. She would also have to be able to use words herself, do so in novel and inventive ways, and differentiate between nouns, adjectives, pronouns, verbs, etc., and use them all with a fair amount of grammatical precision. Don’t get me wrong, I think Chaser is very, very smart. But she’s not that smart!
The Names of All Her Toys
Chaser’s basic ability to respond to verbal cues, relative to her prey drive (toys are prey objects, after all), isn’t unusual. Dogs, like wolves, are social predators, so they’re constantly reading us for social cues. They do this so casually and so often that many times we’re unaware of what’s going on. So, to me, what’s most interesting about Chaser isn’t that she can respond to auditory cues, but the staggering number of them she apparently has stored in her memory banks. And even her owners can’t remember the names of all her toys; they have to rely on a list!
Meanwhile, another study, from UCSD, suggests that babies differentiate between words that relate to pictures of objects and those that don’t in much the same way that adults do. The researchers used MEG (which measures magnetic fields in the brain) and fMRI machines to estimate brain activity in 12 to 18-month old infants when they were shown pictures of familiar objects then heard words that were either a match or a mismatch to the name of the object. (Interestingly one of the tests involved showing the infants a picture of a ball followed by the word ball, versus a picture of a ball followed by the word dog.)
The brains of the infants lit up in certain areas when the word matched the picture. And the same parts of the brain lit up when human adults were given the same tests. Plus, these parts of the brain weren’t those normally associated with language, such as the Broca’s and Wernicke’s areas. In fact, a much older part of the brain—the cerebellum, which controls attention, and motor skills—also lit up.
The third study may seem totally unrelated, but I think it can tell us something about how Chaser learned the names of so many toys, and also why matching words to objects seems to involve the cerebellum in human infants and adults. In this study, researchers at Princeton University tested two groups of students for their ability to retain printed information based on how difficult a font, or typeface, was to read. One group was given a homework assignment printed with either a Comic Sans or Bodoni/Italic font, printed at 60% grayscale, while a second group was given the same assignment printed with the easy-to-read Arial font, printed in pure black. Oddly enough, the first group did substantially better on retention.
The researchers write, “It is not the difficulty, per se, that leads to [learning] improvements but rather the fact that the intervention engages processes that support learning.”
What might those processes be?
Dopamine and Changing Patterns in the Environment
The researchers say that “pinning down the precise mechanism [is] quite challenging.” But in a recent blog article here, I wrote about dopamine circuits in the brain, and how they’re not really “reward circuits,” as they’re often referred to, but attentional pathways. And that what they seem to reward is paying attention to changing patterns in the environment.
From that article: “We’re now discovering that the real purpose of dopamine is to help motivate us to gather new information about the outside world quickly and efficiently. In fact dopamine is released during negative experiences as well as positive ones. (The puppy who gets his nose scratched by the cat doesn’t need further lessons to reinforce the “no-chasing-the-cat” rule; he learns that instantaneously, with a single swipe of the cat’s paw.) This adds further importance to the idea that learning is not as much about pairing behaviors with their consequences as it is about paying close attention to salient changes in our environment: the bigger the changes, the more dopamine is released.”
Could simple pattern recognition explain Chaser’s amazing abilities?
I think so. Chaser is a border collie. (So was Ricoh, who knew the names of over 200 toys and other objects.) And border collies aren’t bred for their linguistic abilities but for their herding skills. In other words, language is not a prerequisite for herding sheep but pattern recognition (which is an evolutionary pre-cursor to language) is.
Dopamine and Changing Patterns in the Environment
I said earlier that in the study done on how infants discriminate between word/object pairs that match and those that don’t, one of the areas in the brain that lit up was the cerebellum, which is operational during motor control as well as during attentional tasks. And if dopamine is designed to make us pay attention to changing patterns in our environment, then it makes sense that the cerebellum—which controls or facilitates attention and motor skills—might also be involved in the cognitive process of finding words and objects that match up, while ignoring those that don’t. This would also explain how the students who had to expend more energy reading the more difficult fonts in their homework printouts retained the information better than those whose homework was easier to read.
I also said that dog owners are often unaware of how easily and how often dogs read our social cues (i.e., pick up on our patterns).
Just as an example, years ago my dog Freddie and I would go on long walks in Central Park during off-leash hours, and he would often do his business (#2) while we were there. If I got distracted while he was in the process of elimination I would sometimes be unable to find where he’d left his “present,” which left me perplexed and frustrated.
Fred, meanwhile, would usually be off sniffing around, or looking for other dogs to meet or squirrels to stalk. Sometimes, as I stopped and looked around, baggie in hand, I would say, mostly to myself, “Fred, where did you do your business?” And for some reason, one I can’t exactly figure out, he would almost invariably stop what he was doing, come back over to the spot, and sniff his own poop. And he never did this on his own. He only did it when I was frustrated and began talking to him.
I didn’t train Fred to do this. There were no external rewards (though I always thanked him for helping me out). And perhaps more importantly, he didn’t look at me or reference me; he never gave any outward signal that he “understood” my words. And yet he always, always went back to his spot and sniffed it when I asked him to.
So, is Fred’s behavior an example of a capacity to understand human language, a facility for pattern recognition, or something else entirely?
What do you think?
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