A new brain study suggests that different kinds of memory may rely on the same underlying brain systems, a finding that could reshape how scientists understand and study memory. Instead of using separate brain regions to retrieve different types of information, the brain appears to draw on overlapping areas regardless of the kind of memory being recalled.

Researchers from the School of Psychology at the University of Nottingham and the Cognition and Brain Sciences Unit at the University of Cambridge focused on two major forms of memory known as episodic and semantic memory. By combining task-based experiments with fMRI data, the team found no meaningful differences in brain activity when participants successfully retrieved either type of memory. The study was published today (January 27) in Nature Human Behaviour.

Understanding Episodic and Semantic Memory

Episodic memory allows people to recall personal experiences that happened at a specific time and place. This type of memory supports the ability to mentally revisit past events, often described as “mental time travel.”

Semantic memory, in contrast, involves remembering facts and general knowledge about the world. These memories are not tied to a specific moment or location and can be recalled independently of when or where the information was learned.

Matching Memory Tasks for a Fair Comparison

To better compare how these two memory types function in the brain, the researchers designed tasks that closely mirrored each other. Forty participants were asked to remember pairings between logos and brand names. Some pairings relied on existing real-world knowledge and formed the semantic task, while others were learned during an earlier study phase and made up the episodic task.

While participants recalled the information, researchers used fMRI (Functional Magnetic Resonance Imaging) scanning to observe brain activity. During the semantic task, participants retrieved brand details from prior knowledge. During the episodic task, they recalled details about the logo and brand pairings learned earlier.

How fMRI Reveals Brain Activity

fMRI is a non-invasive brain imaging technique that tracks activity by measuring changes in blood flow. When specific brain areas become active during tasks such as thinking, speaking, or remembering, they receive more oxygen-rich blood. This process allows researchers to create detailed 3D maps that show which regions are involved in different mental functions and helps support medical research, surgical planning, and the study of neurological conditions.

Surprising Results From Brain Imaging

Dr. Roni Tibon, Assistant Professor in the School of Psychology, led the study and said the findings were unexpected.

“We were very surprised by the results of this study as a long-standing research tradition suggested there would be differences in brain activity with episodic and semantic retrieval. But when we used neuroimaging to investigate this alongside the task-based study, we found that the distinction didn’t exist and that there is considerable overlap in the brain regions involved in semantic and episodic retrieval.”

She added that the results could have important implications for understanding memory-related diseases.

“These findings could help to better understand diseases like dementia and Alzheimer’s, as we can begin to see that the whole brain is involved in the different types of memory, so interventions could be developed to support this view.”

Rethinking How Memory Is Studied

For decades, episodic and semantic memory have been treated as separate systems, leading researchers to study them in isolation. As a result, few studies have examined both types of memory within the same experimental design.

Dr. Tibon believes the new findings could shift that approach.

“Based on what we already knew from previous research in this area, we really expected to see stark differences in brain activity, but any difference we did see was very subtle, I think these results should change the direction of travel for this area of research and hopefully open up new interest in looking at both sides of memory and how they work together.”