Dr. Gregory Berns – TRANSCRIPT
How many of you are dog people? A show of hands. Excellent! How about cat people? OK, you guys can go to the break early. So, of the dog people and the cat people who want to be dog people, how many of you have thought, “Wouldn’t it be great to know what my dog is thinking?” I think everyone else already knows what their dog is thinking, right? I got into this project, and I’m going to tell you a little bit about how – This is basically a stupid dog trick story.
It really started with this dog named Newton, who was really my favorite dog. I’ve had many dogs through my life, but Newton was my favorite, and he lived to be about 15 years old. After he passed away, I thought, I have these tools, this MRI machine, that I have been using for decades to study human decision making and what motivates people, why haven’t we used this on other animals?
Certainly, other animals have many of the same feelings and motivations that people do. But this is kind of an area of science that people don’t like to talk about. So I embarked on this project about four years ago to try to figure out what dogs think, and specifically what dogs think of us. If we’re talking about humans, we have kind of two ways we can think about what other people are thinking: we can either ask them, and sometimes they will tell us if they know, and they want us to know what they are thinking; or we can observe actions, we can observe behaviors, we can try to infer things about what people are thinking from their actions.
With animals, and dogs, of course, we can’t really ask them. We can ask them, and we may think that they tell us, but we really don’t know what they’re thinking. So we’re kind of left with their behaviors: we can observe their actions, and we can try to infer what they are thinking. This is the foundation of behaviorism, and it’s been around since Pavlov. But there are, of course, very tricky issues here, and humans being humans, we tend to anthropomorphize everything. It’s kind of in this area that I became very interested in intrigued with the possibility of trying to figure out what dogs are thinking by using MRI. The technique is straightforward. It’s been around for decades.
The idea is: if we were studying a human, we would put a human in an MRI, have them do some type of task, and we’d measure blood flow or brain activity and then try to figure out what parts of the brain do what. Very straightforward, if you’ve had an MRI, it’s not terribly pleasant, but people will do it. How do we do this with other animals? How do we do it with a dog? I’m going to show you what we found.
Here’s a short video. It’s a what we call our training video, and it demonstrates how we did this. Before I start it, you’re going to see two dogs in this video. The first dog, Callie, is my dog. She was actually the replacement for Newton. She was adopted here in Atlanta from the Humane Society. We loved Newton so much; we could never get another pug, so Callie is the anti-pug. The other dog is McKenzie, a border collie. We just kind of get right into it. I’ll narrate as we go along. [Callie – Introduction to head coil] This’s Mark Spivak. He’s my partner in this endeavor, he’s a dog trainer.
The first thing that we had to do is figure out how do we get dogs to go into a tube, to put a head coil around their head to pick up the brain waves, and hold absolutely still. What you are seeing here, is that Callie is not a particularly obedient dog; she has no particularly special skills. But she does have one very good trait, and that is: she likes hot dogs. Mark is doing what we call clicker training. Every time she approximates what we want her to do, he clicks, and then she gets a hot dog. This’s the very first time she’s been introduced to the thing we call the head coil, and we didn’t know at this point whether this was even going to be possible.
[McKenzie – Introduction to head coil] This dog, McKenzie, a border collie, is highly trained. She’s very skilled in agility, and her owner, as you’ll see, gets her to sit in this coil very quickly. (Video) Dog owner: Good girl! Yes! Is she too far out now? (Video) Gregory Berns: Yeah, basically, we are looking for the brain case to be in the center, right there. That’s good.
(On stage) If you’ve had an MRI, you know that you’re told not to move, right? This is the big challenge of doing this. [Mckenzie – Holding without any chin rest] Up until this point, I didn’t know if this was going to be possible until I saw this. This was literally after about five minutes of training. When I saw that, I knew we could do this. [Callie – Training with chin rest] What you saw McKenzie doing was close but not quite good enough. What we are going after if we’re to achieve data that compares to humans – (Video) GB: You are perfect! Excellent! Perfect job! (On stage) GB: Mark told me I had to be more demonstrative than I am normally. (Video) GB: Perfect! Yes! (On stage) GB: What you notice we did was we introduced a little chin rest because we have to give the dogs a target to put their head on. McKenzie adapts this very quickly. She’s actually in a simulator for an MRI that we built. She’s doing quite well, but this is actually still too much movement. The really difficult part of this is the noise that the scanner makes, playing in the background. These are recordings that we made to acclimate the dogs to the training. It’s very loud. This’s being played at low volume just to get her used to it. But it’s really about 95 decibels, and it’s like jackhammer loud.
(Video) GB: That’s it, that what we are doing! (On stage) GB: This is after about a month or two of training. [Callie – Scammer training] We’re at the real MRI now. This’s probably the most expensive training session ever performed. (Laughter) We get charged about 500 dollars an hour to use the MRI. But we had to use the real thing at a certain point. At this point, we didn’t even know how they would react to the magnetic field. The key thing I want you to notice is these dogs are doing it willingly, and they enjoy it. That is the whole point of this project. We treat these animals as family members. We don’t sedate them, and we don’t restrain them. [Callie – Final training] This’s actually after about two months of training. We made some modifications to the chin rest, and even a shelter dog like Callie can do this. [Full chin rest, ear muffs, tube, hand signals] If you look carefully, you also notice that she’s wearing ear muffs. It’s very important because the scanner is so loud, and the dogs hearing is quite sensitive. [This means “hot dog”]
The other thing that we did – This’s a scientific experiment, really. [This means “no hot dog”] That’s the training video. The “hot dog, no hot dog” hand signals, we started with this because we didn’t know if this was going to work, so we decided we needed to do something really simple. This’s just straight up Pavlovian conditioning where we taught the dogs two hand signals: this means “hot dog,” and this means “no hot dog.” If this technique works, what we should see is activity in the reward system of their brain to this hand signal but not this signal. I also put up a slide here.
Once we started doing this, the word got out amongst the community here in Atlanta that we’re doing this crazy dog scanning project. We’re looking for volunteers, especially people who like to train dogs and have dogs that are very well behaved. That’s still true. If you have a dog that can do this or you think can do this, talk to me. Because the project is still going on, and it’s gotten quite large. You’ve seen the kind of preliminary video. This’s one of my favorite photos because it’s kind of captures – this is the first day we were actually doing the scanning. It captures the human confusion here. We were just standing around trying to figure out how we are going to do this. But Callie knows, she’s been trained, she’s been doing this for two months; so she’s ready to go.
The head wrap is just to keep the ear muffs in place. This is what it look likes from the other end, from the business end of the scanner. This’s actually a dog named Zen. He’s a yellow lab golden retriever. What we’re studying initially is just the reward system response. Very simply, we got these two hand signals, and the idea is we compare the brain response to these two things.
As I said, we have many dogs doing this now, it’s not just shelter dogs. We have dogs from service dog organizations, we have shelter dogs – really all sorts of breeds. Before I show you some of the results, I do want to say something about brain anatomy. A dog brain – this slide is not to scale. A dog brain is probably about the size of a plum or a lemon maybe, depending on the size of the dog. It’s not big, even if you have a big dog, most of the head is muscle, so just going to be aware of that. But I like putting up this slide because it shows the similarities of animal brains. You can immediately make out common structures. You can see towards the right that kind of pretty structure is the cerebellum that controls various types of motor movement, and then below that, there is the brainstem. The really the parts of the brain that are different are what we call the cortex. That’s the upper part, the folded part. The big differences between dog and human have to do with the size of the cortex and how folded it is.
What folding accomplishes is packing a lot more brain surface area into a specific volume. Generally speaking, the more folded a brain, the more surface area, the more brain power, if you will. There are lot of similarities, and there are some differences. What I am particularly interested in are the similarities. Because if we were to have a commonality of experience with dogs, and other animals for that matter, we have to share the same or similar brain structures. Darwin said this 150 years ago. What do the results look like? This’s a very compact way of summarizing an experiment which I showed you where the dogs receive two different hand signals, and we’ve averaged the results over, in this case, 12 dogs, I think though, we’ve done this probably in over 20 dogs. The orange areas show what parts of the brain are more active to this reward signal, this hot dog signal. What I want to emphasize is the brain response is not directly to hot dogs, it’s to the hand signal that means hot dogs. You may think that’s not a big deal; it’s still hot dogs. It’s no surprise that dogs like hot dogs.
But it is a big deal because we train this signal; it’s a symbolic representation of a hot dog that the dog has learned and has learned to recognize this meaning. The particular parts of the brain that are being active are the reward system. There’s kind of two hot spots. There’s a headlight type picture. That’s in an area of the brain called the cortex nucleus. It’s the area of the brain that all mammals have, and it’s the area that has the most dopamine receptors in the brain. It’s kind of the key center that links reward and motivation with action.
Normally, when that’s active in a human or any other animal, it means that something important has happened, and the animal needs to do something. In this case it’s quite simple because they will just eat the hot dogs. Well, so what? So we proved that dog brains like hot dogs. That was just the beginning. This started about four years ago, and we’ve since gone on and done many other experiments. Most of the dogs in these pictures, are still working with us in the project. We’ve done things looking at how their olfaction, or their sensory system for smell works, how they identify different people, and other dogs in their household by smell.
One of the things that we found is that this reward system, the same part of the brain activates when the dogs smell a familiar human, even if the human is not there. It shows that dogs have representations of us of our identities that persist when we are not there. When people ask me, “Do dogs miss us when we are gone?” I have to say yes because we find evidence that they are remembering their humans, that they care about them, and that it’s associated with these reward responses. Is it still just hot dogs?
To answer this question, one of the other things that we did was we actually repeated the experiment I showed you, where we show the different hand signals. With one little twist: we manipulate who gives the signals. Does it matter if the dog’s owner gives a signal? Or whether a stranger comes in and gives the signal? Or even whether a computer gives the signal? Because if you believe Pavlov, and all the behaviorist who followed him, it really shouldn’t matter, because any signal that indicates an upcoming food treat is all the same, if animals and dogs are just kind of robots. But in fact, we did find a difference.
What’s very interesting about it is that not all dogs are the same. For example, my dog Callie had a much greater response in that part of the brain when a stranger gave the signals or even a computer as opposed to me! Other dogs in the project, some of the golden retrievers in the labs can have had the opposite pattern, where their owners had really elicited the strongest brain response. This is very interesting because what it does is it provides us with a neural biomarker of the dog’s personality profile. In fact, what we’ve done is we’ve spun off a new project which we’re very excited about. We’ve partnered with Canine Companions for Independence, which is the largest service dog training organization in the United States.
If you know anything about service dogs, they’re incredibly difficult to train. It’s very expensive, and there’s a very low success rate. Roughly about 35% of dogs that enter these programs to train to be assistance dogs will succeed; the other 2/3 end up being released and adopted to their puppy raisers. So we’ve partnered with CCI, and they’re actually training their dogs to do the MRI procedure. What we’re going to do is try to predict which of those dogs will actually be good service dogs. I really love this project because it shows that even though we started this just as my silly example of trying to understand what my dogs think, and whether they love me, it’s actually gotten much bigger. Dogs are special. They’re the first domesticated animals. They have been with humans since humans have been humans. When we look at their brains, it’s almost like we are looking back in time, and it’s giving us a picture of how the dog-human bond formed. Thank you.