Resume: A new study finds that Eurasian jays exhibit episodic memory, a type of memory previously thought to be unique to humans. The birds were able to remember incidental details of past events, such as the visual features of cups used in an experiment to hide food.
This finding suggests that episodic memory may not be exclusive to humans and could help jays find stored food.
Key Facts:
- Eurasian jays demonstrate episodic memory by recalling incidental details of past events.
- This ability is comparable to ‘mental time travel’ in humans, allowing us to consciously reimagine past experiences.
- Episodic memory can help jays locate stored food.
Source: PLOS
Eurasian jays can remember incidental details of past events, which is characteristic of episodic memory in humans, according to a study published May 15, 2024, in the open access journal PLOS ONE by James Davies of the University of Cambridge, UK and colleagues.
When remembering events, people have the ability to ‘mentally time travel’, where they can consciously reimagine past experiences and possibly recall details that seemed unimportant at the time. Some researchers have suggested that this “episodic memory” is unique to humans.
In this study, Davies and colleagues conducted a memory experiment to test for episodic memory in seven Eurasian jays, birds that excel at remembering the location of stored food.
In the experiment, the birds watched as food was placed under one cup in a row of four identical cups and were then rewarded for correctly selecting the baited cup.
During several tests, the birds were trained to identify the correct cup by remembering its position in the row. Then, during the test, the jays were given an unexpected memory assessment: They watched as food was placed under one of the cups, each of which now had unique visual features, but they were then separated from the cups for 10 minutes while the cups were moved and rearranged.
Despite the changed position of the cups and the additional time delay, the birds still correctly identified the baited cup 70% of the time based on their visual features.
These results suggest that although the visual differences between the cups were unimportant during training, the birds were able to notice these differences during the test and remember them later, similar to episodic memory in humans.
This study indicates that episodic memory could help the jays find food supplies, and the researchers suggest that future studies could investigate whether the birds can perform similar memory feats in other non-food-related scenarios.
The authors add: “Since the jays were able to recall details that had no specific value or relevance at the time the memory was created, this suggests that they are able to capture incidental information within a remembered event, back to call and access it. This is an ability characteristic of the type of human memory with which we mentally ‘relive’ past events episodes), known as ‘episodic’ memory.”
About this memory research news
Author: Hannah Abdallah
Source: PLOS
Contact: Hanna Abdallah – PLOS
Image: The image is credited to Neuroscience News
Original research: Open access.
“Eurasian jays (Garrulus glandarius) exhibit episodic memory through the incidental encoding of information” by James R. Davies et al. PLOS One
Abstract
Eurasian jays (Garrulus glandarius) exhibit episodic memory through the incidental encoding of information
Episodic memory describes the conscious reimagining of our memories and is often considered a uniquely human ability.
Because these phenomenological components are embedded within its definition, major difficulties arise when investigating the presence of episodic memory in non-human animals.
Importantly, however, when we as humans remember a specific experience, we can recall details from that experience that did not affect our needs, thoughts, or desires at the time.
Nevertheless, this ‘incidental’ information is automatically encoded as part of memory and is then recalled within a holistic representation of the event.
The incidental encoding and unexpected demand paradigm represents this characteristic feature of human episodic memory and can be used to investigate memory recall in nonhuman animals.
However, without evidence for the associated phenomenology during recall, this type of memory is termed ‘episodic’-like it memory’.
Using this approach, we tested seven Eurasian jays (Garrulus glandarius) about their ability to use incidental visual information (associated with experimenter-created ‘caches’) to solve an unexpected memory test.
The birds performed above chance levels, suggesting that Eurasian jays can encode, retain, retrieve and access incidental visual information within a remembered event, an ability indicative of episodic memory in humans.