Canine Neuroscience
The ground-breaking study in which two dogs were trained to keep still and have an fMRI.
By Zazie Todd, PhD
By Zazie Todd, PhD
The main problem with the neuroscience of dogs is that they would
have to be sedated to be in the scanner, and then their brain wouldn’t be doing
its normal stuff. Until now.
Previous work on people and monkeys has shown that the caudate region of the brain is activated in expectation of a reward. The scientists found activation in the ventral caudate region of the dogs’ brains in response to the hand signal that denoted a treat, but not for the other hand signal; this shows the dog had learned to expect a reward.
This study is exciting because it demonstrates that canine neuroscience is possible. A future study might look for any differences in activation depending on whether it is the owner or someone else who makes the hand signal. This would tap into the same wider debate as that considered by Feuerbacher and Wynne in their investigation of whether dogs and wolves prefer treats or social interaction as a reward.
A team of scientists led by Gregory Berns at Emory
University has successfully trained two dogs to go into the fMRI scanner and
keep still long enough for a brain scan. Prof Berns says he got the idea from
realizing what military dogs are trained to do – if a dog can parachute out of
a plane with its handler, he thought, then surely it could do an fMRI.
The dogs are Callie, a two-year-old feist (small hunting
dog), and McKenzie, a three-year-old border collie. And while McKenzie does
agility, Callie had only had basic obedience training, and is a rescue dog. (If
anyone ever tries to say negative things about rescue dogs, tell them about
Callie!).
The dog training was complex and took place over several months. A mock-up of the scanner was made for each dog, including a replica head coil, a tube of the same size as the real thing, and a patient table within the tube with a head rest for the dog. Because dogs’ hearing is so sensitive, they also had to learn to wear headphones to protect their ears. The first times the scientists actually started the scan, the sound caused a startle reaction, so they played the sound throughout the training sessions to get the dog used to the noise that the machine makes.
What task was used for this ground-breaking experiment? The researchers wanted to know if there is a different pattern of activity in the brain when the dog sees a hand-signal that means their owner is about to give them a treat, compared to when they see a hand-signal that means no treat. The hand signals were left hand held up to mean the dog was about to receive a piece of hot dog, and both hands pointing horizontally to each other to mean no hot dog was forthcoming.
The dogs were trained on this task for ten minutes a day for several weeks prior to the actual experiment. The dog had to hold still for ten seconds while the hand signal was made, and then if it was the ‘treat’ signal the owner reached into the scanner to deliver some hot dog; the dog could move to get the treat and then had to go back into position.
The dogs were trained using positive reinforcement and had to lie still with their head in a chin rest. Once the dog was used to this, the chin rest was moulded to give a custom fit, because it’s important for the dog’s head not to move in order to allow the scan to be interpreted. Finally, they were ready for the real thing.
What task was used for this ground-breaking experiment? The researchers wanted to know if there is a different pattern of activity in the brain when the dog sees a hand-signal that means their owner is about to give them a treat, compared to when they see a hand-signal that means no treat. The hand signals were left hand held up to mean the dog was about to receive a piece of hot dog, and both hands pointing horizontally to each other to mean no hot dog was forthcoming.
The dogs were trained on this task for ten minutes a day for several weeks prior to the actual experiment. The dog had to hold still for ten seconds while the hand signal was made, and then if it was the ‘treat’ signal the owner reached into the scanner to deliver some hot dog; the dog could move to get the treat and then had to go back into position.
Do you think these border collies are anticipating a reward? Photo: Ksenia Rayknova / Shutterstock |
Previous work on people and monkeys has shown that the caudate region of the brain is activated in expectation of a reward. The scientists found activation in the ventral caudate region of the dogs’ brains in response to the hand signal that denoted a treat, but not for the other hand signal; this shows the dog had learned to expect a reward.
This study is exciting because it demonstrates that canine neuroscience is possible. A future study might look for any differences in activation depending on whether it is the owner or someone else who makes the hand signal. This would tap into the same wider debate as that considered by Feuerbacher and Wynne in their investigation of whether dogs and wolves prefer treats or social interaction as a reward.
The experiment was conducted with great care for the dogs’
wellbeing and they were free to exit the scanner at any time. The researchers
make some useful comments about the ethics of this kind of study; for example,
they say it wouldn’t be appropriate to use laboratory-bred dogs as they would
have no choice whether to take part in the experiment.
Emory University made a short video about the research which
you can see here.
If you could train your dog to go in an MRI scanner, what
would you test?
Reference:
Berns, G. S., Brooks, A. M., & Spivak, M. (2012). Functional MRI in awake unrestrained dogs. PloS one, 7(5), e38027.