Dogs remember what we do

Dogs recall humans’ actions, even if they didn’t seem important at the time.

Anyone who’s trained a dog knows they have good memories, especially if treats are involved. But how much does your dog remember about what you’ve done in your everyday life? New research suggests dogs recall the seemingly mundane actions of their owners, even if they didn’t know they’d be expected to. Lead author Claudia Fugazza tells us more.

ResearchGate: What led you to conduct this study?

Claudia Fugazza: We had previously revealed that dogs are able to imitate human actions even after long delays. This gave us the idea that we could use the same method to study different forms of memory in dogs. In particular, episodic memory of complex, context- and content-rich events had not been tested before in non-human animals. We wanted to ask dogs, “Do you remember what your owner did?” in a situation very close to real life.

RG: What is episodic memory? How does it differ from other kinds of memory?

Fugazza: Episodic memory is the ability to remember past events that were not known to be important at the time of encoding. In order to recall an event that was encoded incidentally, one has to mentally travel back in time to the situation where the event occurred and remember it. This is different than semantic memory, which is memory of facts and rules encoded explicitly. The difference between semantic and episodic memory could be framed as the difference between knowing and remembering.

A dog observes its owner standing on a chair. Later, after receiving the "Do it!" command, the dog climbs on the chair to imitate the action. Credit: Attila Molnar

RG: How did you assess dogs’ episodic memory?

Fugazza: We trained dogs to imitate human actions with a training method called “Do as I do.” With this method, dogs learn to match their behaviour to actions demonstrated by humans with the command “Do it!” For example, the owner jumps in the air, then gives the “Do it!” command and the dog will jump in the air too. Dogs trained with this method can imitate their owners’ actions even after a delay of 24 hours. Thus, giving dogs the “Do it!” command after a delay is a way of asking them, “Do you remember what your owner did?”

In order to test episodic-like memory, we needed the imitation test to be unexpected for the dogs. So we re-trained them. Instead of expecting an imitation command, they expected the command “lie down” irrespective of the actions demonstrated by the owner. This taught dogs that the demonstrated actions were not relevant to solving the task. Then, after making sure that dogs did not expect to imitate anymore, we showed them demonstrations of everyday actions and, after a delay, surprised them with the “Do it!” command. If dogs can remember and imitate when unexpectedly tested, this means that they use episodic-like memory to recall the demonstration.

RG: What were the results?

Fugazza: Dogs could remember and imitate their owners’ actions, however their memory decayed faster in this study than in studies when the recall test was expected. This makes sense, as episodic memory is known to decay faster than other types of memory. In the unexpected tests, dogs looked longer at their owners, a behavioural sign of violation of expectation, suggesting that they were indeed surprised to be required to imitate.

A dog imitates its owner, sitting on the table as he had earlier. Credit: Claudia Fugazza

RG: How might this play out in real life relationships between dogs and their owners?

Fugazza: This study suggests that dogs may encode incidentally and remember much of what we do in our everyday life, although it may seem irrelevant for them. This is a skill that might be useful for a species living in a rich and complex environment where human companions can be considered knowledgeable partners to learn from. Owners should know that their dogs remember what they do, even when it seems irrelevant for the dog.

RG: Do other species have episodic memory?

Fugazza: There is evidence of episodic memory in other species too, including primates, rats, and pigeons. However previous studies tested memory of very simple stimuli like the presence or absence of food. Moreover, the tests were conducted in a laboratory setting, which is in many ways not like real life. Whether non-human animals can use episodic memory to recall more complex events that happen in real-life situations was not previously known. Our study is the first to test whether pet dogs in their own natural environment can remember complex and content-rich events. Moreover, this is the first study to assess memory of others’ actions. The dogs remembered events they had witnessed, but had not performed.

Featured image courtesy of Clay Larsen.