Summary: New research shows that retrieving episodic (personal) and semantic (fact-based) memories engages largely the same brain regions. The study challenges the long-standing idea that these two memory types rely on separate neural systems and suggests a more integrated, whole-brain view of memory retrieval.
Source: University of Nottingham
Key Facts:
- The discovery: Substantial overlap was found in the brain areas activated during successful semantic and episodic retrieval, countering the notion of distinct neural systems for each.
- Methodology: Forty participants underwent fMRI while recalling logo–brand pairings. Some pairs reflected real-world knowledge (semantic task), while others had been learned during an initial study phase (episodic task).
- Implications: Recognizing that similar brain networks support both memory types could reshape research approaches and inspire new intervention strategies for conditions such as Alzheimer’s disease and other dementias.
- Collaboration: This study was conducted jointly by the University of Nottingham and the University of Cambridge.
Researchers from Nottingham’s School of Psychology and the Cognition and Brain Sciences Unit at the University of Cambridge designed closely matched tasks to compare neural activations for episodic and semantic retrieval. Using task-based measures alongside functional magnetic resonance imaging (fMRI), the team found no clear differences in the patterns of brain activity associated with successful retrieval of episodic versus semantic memories. The peer-reviewed findings appear in Nature Human Behaviour.
Episodic memory enables people to recall personal events located in a particular time and place, often described as a form of “mental time travel.” Semantic memory stores general facts and knowledge about the world, independently of when or where that information was first acquired. In many prior studies, these memory systems have been examined separately, an approach that may have exaggerated their distinction.
To avoid confounds from differing task demands, the research team matched the semantic and episodic tasks as closely as possible. Participants studied and later recalled pairings between brand logos and names. In the semantic condition, the pairings corresponded to pre-existing real-world knowledge; in the episodic condition, pairings had been learned during an earlier study phase. While participants attempted to retrieve the associated brand information, fMRI recorded whole-brain activity.
fMRI is a non-invasive imaging technique that detects changes in blood flow related to neural activity, producing dynamic three-dimensional maps of the brain as people perform cognitive tasks. It is widely used to identify active networks during tasks such as memory retrieval, language processing, and motor actions.
Dr Roni Tibon, Assistant Professor in the School of Psychology at the University of Nottingham and lead author of the study, said the results were unexpected given the prevailing research tradition. Rather than finding clear neural separation, the team observed extensive overlap across brain regions during successful retrieval of both episodic and semantic memories. She noted that these findings encourage a shift away from treating the two memory types as entirely separate systems and toward studying how they interact within common neural networks.
Dr Tibon added that reconceptualizing memory as involving shared, distributed networks may have practical benefits for understanding and treating memory disorders. If both forms of memory draw on overlapping brain systems, therapeutic interventions or cognitive strategies could be devised to support memory function more broadly, potentially aiding people with dementia or Alzheimer’s.
The study also highlights a methodological issue in memory research: because episodic and semantic memory have traditionally been studied in isolation, within-study designs that directly compare the two have been scarce. By using tightly matched tasks and rigorous imaging methods, this research addresses that gap and produces evidence that any differences in activation between memory types are subtle rather than categorical.
Dr Tibon concluded that these results should encourage the field to integrate investigations of episodic and semantic memory, exploring how common neural mechanisms contribute to different aspects of remembering and how these systems support everyday cognition.
Editorial Notes:
- This article was edited by a Neuroscience News editor.
- The journal paper was reviewed in full for accuracy.
- Additional context and clarifications were added by editorial staff.
About this Memory Research
- Author: Emma Thorne
- Source: University of Nottingham
- Contact: Emma Thorne – University of Nottingham
- Image: The image is credited to Neuroscience News
Original Research:
Closed access. “Neural activations and representations during episodic versus semantic memory retrieval” by Roni Tibon et al., Nature Human Behaviour. DOI: 10.1038/s41562-025-02390-4
Abstract
Tibon, R., Greve, A., Humphreys, G. et al. Neural activations and representations during episodic versus semantic memory retrieval. Nat Hum Behav (2026). DOI: 10.1038/s41562-025-02390-4
Although neuropsychological evidence has long supported a distinction between episodic and semantic memory, neuroimaging studies have frequently reported overlapping activations for the two forms of remembering. Such overlap could reflect shared mechanisms or arise from task design differences or incomplete fMRI coverage. To clarify this, the authors compared neural activations and representations linked to successful retrieval of episodic and semantic memories using more closely matched tasks. A total of n = 40 participants recalled logo–brand pairings that either reflected real-world knowledge (semantic) or were learned during a prior study phase (episodic). Analyses of predefined networks and task-activated clusters found no reliable differences between successful semantic and episodic retrieval, with Bayes factor evidence supporting the null hypothesis of no difference. Protocol registration: The Stage 1 protocol for this Registered Report was accepted in principle on 15 September 2021.