Summary: A new study finds that Eurasian jays exhibit episodic-like 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 characteristics of cups used in a food-hiding experiment.
This finding suggests that episodic memory may not be exclusive to humans and could aid jays in finding stored food.
Key Facts:
- Eurasian jays demonstrate episodic-like memory by recalling incidental details of past events.
- This ability is similar to “mental time travel” in humans, which allows us to consciously reimagine past experiences.
- Episodic-like memory may 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, humans have the ability of “mental time travel,” consciously reimagining past experiences and potentially recalling 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 ran a memory experiment to test for episodic-like memory in seven Eurasian jays, birds that excel at remembering the location of stored food.
In the experiment, the birds watched food get placed beneath one cup in a line of four identical cups and were then rewarded for correctly selecting the baited cup.
Over several trials, the birds were trained to identify the correct cup by remembering its position in line. Then, at test, the jays were given an unexpected memory assessment: they watched food get placed beneath one of the cups, which now all had unique visual characteristics, but they were then separated from the cups for 10 minutes while the cups were relocated and rearranged.
Despite the changed positions of the cups and the added time delay, the birds still correctly identified the baited cup according to their visual characteristics 70% of the time.
These results suggest that even though visual differences between the cups were unimportant during training, the birds were able to notice those differences at test and recall them later, similar to episodic memory in humans.
This study indicates that episodic-like memory might aid jays in finding food stores, and the researchers suggest that future studies might investigate whether the birds can perform similar feats of memory in other non-food-related scenarios.
The authors add: “As the jays were able to remember details that held no specific value or relevance at the time that the memory was created, this suggests that they are able to record, recall, and access incidental information within a remembered event. This is an ability that characterises the type of human memory through which we mentally ‘relive’ past events (or episodes), known as ‘episodic’ memory.”
About this memory research news
Author: Hanna Abdallah
Source: PLOS
Contact: Hanna Abdallah – PLOS
Image: The image is credited to Neuroscience News
Original Research: Open access.
“Eurasian jays (Garrulus glandarius) show episodic-like memory through the incidental encoding of information” by James R. Davies et al. PLOS One
Abstract
Eurasian jays (Garrulus glandarius) show episodic-like memory through the incidental encoding of information
Episodic memory describes the conscious reimagining of our memories and is often considered to be a uniquely human ability.
As these phenomenological components are embedded within its definition, major issues arise when investigating the presence of episodic memory in non-human animals.
Importantly, however, when we as humans recall a specific experience, we may remember details from that experience that were inconsequential to our needs, thoughts, or desires at that time.
This ‘incidental’ information is nevertheless encoded automatically as part of the memory and is subsequently recalled within a holistic representation of the event.
The incidental encoding and unexpected question paradigm represents this characteristic feature of human episodic memory and can be employed to investigate memory recall in non-human animals.
However, without evidence for the associated phenomenology during recall, this type of memory is termed ‘episodic-like memory’.
Using this approach, we tested seven Eurasian jays (Garrulus glandarius) on their ability to use incidental visual information (associated with observed experimenter made ‘caches’) to solve an unexpected memory test.
The birds performed above chance levels, suggesting that Eurasian jays can encode, retain, recall, and access incidental visual information within a remembered event, which is an ability indicative of episodic memory in humans.
