Beyond Human Experience: The Surprising Story of Episodic Memory Across Species

More Than Just Memories

Imagine trying to remember what you had for breakfast last Tuesday. As you mentally travel back in time, you might recall the taste of toast, the morning sunlight streaming through the window, and your amusement at a news story you read. This ability to relive personal experiences isn't unique to humans—and the discovery of its presence throughout the animal kingdom is revolutionizing our understanding of memory itself.

For decades, scientists believed that episodic memory—the capacity to recall specific events, complete with their contextual details of what, where, and when—was a uniquely human trait. Today, that assumption is being dramatically overturned. From birds that remember hidden food caches to infants forming memories long before they can speak, research is revealing that the mental time travel we often take for granted connects us to creatures great and small in surprising ways.

This article explores the fascinating science of episodic memory through a comparative lens, examining how this crucial cognitive function appears across species, how it develops in humans, and what it reveals about the very nature of memory. Join us on a journey through the most personal form of memory we possess—one that shapes our identities, connects us to other species, and continues to surprise scientists with its complexity and distribution throughout the animal kingdom.

What Exactly is Episodic Memory?

The Architecture of Personal Recall

Episodic memory refers to our ability to store and retrieve information about personally experienced events, complete with their specific contextual details ⁶ . Think of it as your brain's personal diary, recording not just what happened, but where and when it occurred, and even how you felt about it. This differs from semantic memory, which handles facts and general knowledge—like knowing that Paris is the capital of France, without necessarily remembering when you learned that fact.

The term "episodic memory" was first coined by psychologist Endel Tulving in 1972, who emphasized its unique characteristic of enabling "mental time travel" ⁸ . This allows us to consciously re-experience past events, much like replaying a mental video clip complete with sensory details and emotional context.

Episodic Memory in Daily Life

To better understand this concept, consider these real-world examples:

• A coach recalling specific plays from a game years earlier, including the positions of players and the outcome of each move ⁸ .
• Remembering where you parked your car at the shopping mall today, as opposed to your general knowledge of where the parking lot is located.
• Flashbulb memories—those vivid recollections of where you were and what you were doing during historically significant or emotionally charged events ⁸ .

The Evolutionary Perspective: Episodic Memory Across Species

The Animal Mind: Beyond Instinct

For many years, scientists considered episodic memory a uniquely human capacity, partly because it seemed to require conscious awareness that was difficult to prove in animals. However, a groundbreaking study with scrub jays in 1998 began to challenge this assumption . These birds demonstrated an ability to remember what food they had hidden, where they hid it, and when they hid it—precisely the "what, where, when" criteria that defines episodic-like memory.

This discovery opened the floodgates for research into episodic-like memory in other species. Rats have shown the ability to remember specific events in maze experiments, while meadow voles have demonstrated capacity to recall the "what", "where", and "when" of a single past event . Even dogs have shown incidental memory capabilities, remembering unexpected information that proves useful later .

Scrub jays demonstrate episodic-like memory by remembering what food they cached, where, and when.

Why Would Animals Need Episodic Memory?

From an evolutionary perspective, episodic-like memory provides significant survival advantages ⁵ . The ability to remember which food sources were richest, when certain predators are most active, or where safe shelter can be found would offer clear benefits. This challenges the notion that animals live purely "in the moment"—instead, many species appear to use memories of past experiences to guide future decisions.

A Groundbreaking Experiment: Tracing the Origins of Infant Memory

The Mystery of Infantile Amnesia

Most adults cannot remember specific events from their earliest years—a phenomenon known as infantile amnesia. Traditional explanations suggested that the hippocampus, the brain's memory center, was too underdeveloped in infants to form stable memories. However, a revolutionary 2025 Yale study published in Science has turned this assumption on its head ¹ .

Methodology: Peering into the Infant Brain

The research team, led by Nick Turk-Browne and Tristan Yates, developed an innovative approach to test memory in pre-verbal infants. They showed infants aged four months to two years a series of images featuring new faces, objects, or scenes. Later, after presenting several other images as distractors, researchers showed the infants a previously viewed image alongside a completely new one ¹ .

The clever part of this methodology leveraged a well-established principle of infant behavior: babies tend to look longer at things they recognize as familiar. Therefore, if an infant stared longer at the previously seen image compared to the new one, this was interpreted as recognition—evidence that they remembered the image ¹ .

What made this study particularly innovative was its use of functional magnetic resonance imaging (fMRI) with awake infants—a historically challenging feat given infants' short attention spans and difficulty remaining still. The researchers measured activity in the infants' hippocampus while they viewed the images, allowing them to directly observe the relationship between brain activity and memory formation ¹ .

Results and Analysis: Memory Encoding Happens Earlier Than We Thought

The findings were striking. When infants showed greater hippocampal activity while initially viewing an image, they subsequently looked longer at that same image when it reappeared later. This correlation between encoding activity and later recognition provides compelling evidence that episodic memories can indeed be encoded during infancy ¹ .

Furthermore, the research revealed that this memory encoding was strongest in the posterior portion of the hippocampus—the same region associated with episodic memory in adults. While these effects were present across all infants in the study, they were strongest in those older than 12 months, suggesting that episodic memory abilities strengthen throughout infancy ¹ .

Perhaps most importantly, this study suggests that infantile amnesia may not be an encoding problem at all, but rather a retrieval issue. The memories are formed, but we lose our ability to access them as we develop linguistically and cognitively ¹ . As Turk-Browne notes, "Tristan's work in humans is remarkably compatible with recent animal evidence that infantile amnesia is a retrieval problem" ¹ .

The Scientist's Toolkit: Methods for Studying Episodic Memory

Research into episodic memory relies on sophisticated tools and methodologies tailored to different populations.

Neuroimaging Techniques

Behavioral Paradigms for Non-Verbal Populations

Clinical Assessment Tools

Conclusion: The Future of Memory Research

The study of episodic memory has come a long way from being considered a uniquely human capacity. We now know that various species possess forms of episodic-like memory, and that human infants begin encoding specific memories much earlier than previously thought. This comparative approach doesn't diminish human uniqueness but rather highlights the evolutionary foundations of our mental lives.

Future research directions are particularly exciting. The Yale team is currently exploring whether infants and children can remember home videos taken from their perspective as younger babies, with pilot results suggesting these memories might persist until preschool age before fading ¹ . Meanwhile, researchers at the London School of Economics are leveraging developments in artificial intelligence to explore parallels between biological and artificial memory systems ⁵ .

These advances could have profound implications. Understanding how episodic memory develops might lead to earlier detection of memory-related disorders. Discovering how memories are encoded and potentially retrieved could inform new treatments for conditions like Alzheimer's disease, where episodic memory is often the first casualty.

As Turk-Browne entertains the "radical, almost sci-fi possibility" that infant memories may endure in some form into adulthood despite being inaccessible, we're reminded that the study of memory remains one of the most fascinating frontiers in neuroscience ¹ . What we're truly discovering is not just how we remember, but how these intricate threads of recollection connect us to other species, to our own past selves, and ultimately, to the very essence of human experience.