Neuronal allocation and sparse coding of episodic memories in the human hippocampus.

Catherine W Tallman, Peter N Steinmetz, John T Wixted

Abstract read

In one paragraph

Article in Scientific reports, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.

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0cells of the map it votes in

1citing papers in PubMed

–field-weighted citation impact

1 · What the graph read from it

What it found

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3 · Its place in the literature

Who cites it

1 citing paper in PubMed.

Mandarin speech-based early detection of SCD: a feature-fusion residual network method.Alzheimer's & dementia : the journal of the Alzheimer's Association · 2026
Article

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5 · Who and what money

Authors and funding

3 authors.

Catherine W TallmanDepartment of Psychology, University of California San Diego, San Diego, CA, USA. ctallman@ucsd.edu.

Peter N SteinmetzNeurtex Brain Research Institute, Dallas, TX, USA.

John T WixtedDepartment of Psychology, University of California San Diego, San Diego, CA, USA.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Neurocomputational models hold that individual episodic memories are represented by a sparse, pattern-separated coding scheme in the hippocampus. Animal studies further suggest that the allocation of neurons to such codes is non-random and may be biased by their excitability at the time of encoding. Here, utilizing an independent dataset of single-unit recordings from epilepsy patients, we report that only remembered items that elicited a relative increase in firing at encoding were associated with a sparse, pattern-separated neural code at retrieval, and this effect was specific to the hippocampus. These findings provide evidence in humans that remembered episodic memories are represented by sparse codes in the hippocampus. Although excitability is not typically defined in terms of firing rates, the present results raise the possibility that excitability at encoding may influence the likelihood of recruitment into such codes.

Indexed as

HippocampusMemory, EpisodicNeuronsAction PotentialsAdultEpilepsyFemaleHumansMaleModels, NeurologicalYoung AdultEpisodic memoryHuman hippocampusNeuronal allocationSingle-unit recordingSparse codingSubsequent memory

Identifiers

PMID41253898

DOI10.1038/s41598-025-21967-7

PMCPMC12627520

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.