Just like people can recall events from the past – even those that seemed insignificant at the time – dogs also show signs of having episodic memories. They are capable of remembering our actions, even when they don't expect to have their memories tested.

Whether animals have episodic memory – that is that they can really remember personal events and specific episodes from their life which occurred at a particular time and place – has been debated by scientists for years. This ability is associated with self-awareness.

Multiple studies have tried to answer this question, but designing experiments to assess self-awareness unambiguously is tricky. None of the research has been fully conclusive.

Focusing on one feature of episodic memory known as incidental encoding may be a good strategy in animals. Incidental encoding refers to the process of storing important information in the brain without knowing that it has to be remembered or that it will be important later.

In this new study published in the journal Current Biology, the scientists have assessed whether this process takes place in dogs.

Do as I Do

The scientists have developed a method to investigate the ability of dogs to recall past events when there was no expectation that their memory was being tested – it is a modified version of the ''Do as I Do'' paradigm, based on the idea that dogs can imitate human actions after a delay. Scientists who use this paradigm typically train the animals to watch them perform an action and then to do the action themselves when they are told "do it".

Jessie, pictured in Hertfordshire in 2016 Callum Paton

The problem is that this is not enough to prove dogs have episodic memories – it just shows they can be trained to remember and copy a specific action. To show that episodic memory is involved, the scientists needed to demonstrate that dogs remember what they just saw, even when they weren't expecting to be asked or rewarded.

This is what they set out to do in this study: they trained 17 dogs to imitate human actions with the "Do as I Do" training method, followed by another training in which dogs were taught to lie down after watching the scientists perform an action.

In the next stage of the research, when the dogs were lying down, the scientists surprised them by saying "Do It" and the dogs did. This suggests that the animals recalled the action done by the scientists even when they didn't expect that they would have to remember it and perform it themselves. This is a sign of episodic-like memory and potential self-awareness.

Study lead author Claudia Fugazza concluded: "From a broad evolutionary perspective, this implies that episodic-like memory is not unique and did not evolve only in primates but is a more widespread skill in the animal kingdom."