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Study-phase reinstatement predicts subsequent recall

Nature Neuroscience volume 28, pages 883–890 (2025)Cite this article

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Abstract

Can the brain improve the retrievability of an experience after it has occurred? Systems consolidation theory proposes that item-specific cortical reactivation during post-encoding rest periods facilitates the formation of stable memory representations, a prediction supported by neural evidence in humans and animals. Such reactivation may also occur on shorter timescales, offering a potential account of classic list memory phenomena but lacking in support from neural data. Leveraging the high temporal specificity of intracranial electroencephalography (EEG), we investigate spontaneous reactivation of previously experienced items during brief intervals between individual encoding events. Across two large-scale free-recall experiments, we show that reactivation during these periods, measured by spectral intracranial EEG similarity, predicts subsequent recall. In a third experiment, we show that the same methodology can identify post-encoding reactivation that correlates with subsequent memory, consistent with previous results. Thus, spontaneous study-phase reinstatement reliably predicts memory behavior, linking psychological accounts to neural mechanisms and providing evidence for rapid consolidation processes during encoding.

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Fig. 1: Experimental tasks and methods for experiments 1 and 2.
Fig. 2: Similarity of spectral representations of neural signals during two word presentations on the same list.
Fig. 3: Similarity of neural signals at time points during encoding presentations and inter-item intervals as a function of subsequent recall.
Fig. 4: Experiment 3 task design and analysis of post-encoding reinstatement.

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Data availability

De-identified data from the three experiments in this study are available on OpenNeuro (experiment 1, https://openneuro.org/datasets/ds004809/; experiment 2, https://openneuro.org/datasets/ds004789/; experiment 3, https://openneuro.org/datasets/ds005411/).

Code availability

The software used to perform analyses and generate figures for the paper is available on GitHub at https://github.com/pennmem/study_phase_reinstatement.

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Acknowledgements

We are very grateful to all patients who participated in this study. We thank R. Colyer, A. Rao and R. DeHaan for help with data collection and quality control and A. Schapiro, A. Broitman and N. Greene for comments on the paper. We gratefully acknowledge support from NIH grant MH55687.

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Authors and Affiliations

  1. Department of Psychology, University of Pennsylvania, Philadelphia, PA, USA

    David J. Halpern & Michael J. Kahana

  2. Department of Neurosurgery, University of Texas Southwestern, Dallas, TX, USA

    Bradley C. Lega

  3. Department of Neurosurgery, Emory School of Medicine, Atlanta, GA, USA

    Robert E. Gross

  4. Department of Neurosurgery, Thomas Jefferson University, Philadelphia, PA, USA

    Chengyuan Wu

  5. Department of Neurology, Thomas Jefferson University, Philadelphia, PA, USA

    Michael R. Sperling

  6. Department of Neurosurgery, Beth Israel Deaconess Medical Center, Boston, MA, USA

    Joshua P. Aronson

  7. Department of Neurology, Dartmouth–Hitchcock Medical Center, Lebanon, NH, USA

    Barbara C. Jobst

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  1. David J. Halpern
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  2. Bradley C. Lega
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  3. Robert E. Gross
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  4. Chengyuan Wu
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  8. Michael J. Kahana
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Contributions

D.J.H. and M.J.K. developed hypotheses and designed the study. M.J.K. acquired funding. B.C.L., R.E.G., C.W., M.R.S., J.P.A. and B.C.J. recruited study participants, implanted electrodes and collected data. D.J.H. analyzed data. D.J.H. and M.J.K. wrote the paper.

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Correspondence to Michael J. Kahana.

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Halpern, D.J., Lega, B.C., Gross, R.E. et al. Study-phase reinstatement predicts subsequent recall. Nat Neurosci 28, 883–890 (2025). https://doi.org/10.1038/s41593-025-01884-8

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