Dogs are humans’ constant companions, providing cherished memories to look back on. Canines remember their humans, too — numerous heart-wrenching reunions between an owner and their pup caught on video can confirm. But do dogs recall past events the way humans do?
That’s a tough question for pet researchers to answer, but recent studies may provide a more concrete window into your dog’s mind.
What is memory?
To understand the roots of this canine debate, let’s first unpack two types of memory.
The first is “semantic memory.” This refers to generalized, long-term knowledge we have accumulated about the world around us. These memories are tied to concepts and facts we consciously learn — such as arithmetic or language — and are not connected to time.
There’s little debate about whether dogs experience semantic memories. Pups remember their owners by their scent and appearance. They recall which toys they like, their favorite spot to lounge on the couch, and their preferred brand of kibble.
But whether dogs experience “episodic memory” — the ability to recall specific experiences from moments in the past — isn’t clear. Most of our memories associated with a time and place count as episodic, such as the specific meal you ordered or the color of the car you rented on a trip you took years prior.
Defining whether a memory is episodic, especially in dogs, can be hard.
“Some definitions are based on the content — what is remembered — and some definitions are based on the way it is remembered,” Claudia Fugazza, a canine cognition researcher at Eötvös Loránd University tells Inverse.
In her research, Fugazza considers episodic memory as “remembering something that, at the time the event happened, you did not know it was important [or] to be remembered.”
According to this definition, it’s not so important whether a dog can generally remember its owner’s face or recall a specific past event, but, rather, the way information gets encoded in the dog’s brain in both instances.
Do dogs have specific memories?
The reason dogs have not previously been considered to have episodic memory probably has to do with how “episodic memory has traditionally been linked to ‘self-awareness,” Fugazza says.
Naturally, “if you are able to ‘replay’ scenes of the past in your mind, then you must be aware that you were there,” says Fugazza. Scientists have long debated whether self-awareness is uniquely human or present in other animals.
But as her recent canine research reveals, episodic memory is a lot more complicated than just self-awareness.
In 2016, Fugazza and her colleagues published a study that tested whether dogs can use episodic memory to recall humans’ past actions. In the study, the researchers trained dogs to imitate human actions on command, followed by a simple training exercise. Dogs were tested on their ability to recall specific actions one minute and one hour after the training exercises.
Researchers found dogs could recall human actions in both instances, meaning dogs could remember a specific moment in the past.
“This study shows that dogs can form episodic-like memories of past events,” Fugazza says.
However, Fugazza adds they could only conclude dogs have “episodic-like” memory since they can’t say whether canines possess self-awareness or not.
She published a second 2020 study on episodic memories in dogs, testing whether dogs could remember their past actions. The researchers found dogs were able to repeat or “represent their own actions and recall them using episodic-like memory.”
Therefore, dogs are “more aware of what they do than previously thought,” Fugazza says.
Can dogs recall events that occurred long ago?
So, we know dogs can recall specific actions from the past, but how long do these memories last?
It's possible dogs can remember moments from the past, but that memory may fade quickly. A 2010 study testing dogs’ spatial memory (how well a human or animal can record and recall information) found their memory capacity was “surprisingly low.” Similarly, Fugazza’s 2016 study found this recall ability in dogs “declined more with time.”
Yet, this erosion of memories over time is far from unique to canines.
“Of course, memory decays. And episodic memory, in dogs, like in humans, decays faster than semantic memory,” Fugazza says.