Abstract
Our experiences contain countless details that may be important in the future, yet we rarely know which will matter and which will not. This uncertainty poses a difficult challenge for adaptive decision-making, as failing to preserve relevant information can prevent us from making good choices later on. One solution to this challenge is to store detailed memories of individual experiences that can be flexibly accessed whenever their details become relevant. By allowing us to store and recall specific events in vivid detail, the human episodic memory system provides exactly this capacity. Yet, whether and how this ability supports adaptive behaviour is poorly understood. Here we aimed to determine whether people use detailed episodic memories to make decisions when future task demands are uncertain. We hypothesized that the episodic memory system’s ability to store events in great detail allows us to reference any of these details if they later become relevant. We tested this hypothesis using a novel decision-making task in which participants encoded individual events with multiple features and later made decisions based on these features to maximize their earnings. Across 5 experiments (total n = 535), we found that participants referenced episodic memories during decisions in feature-rich environments and that they did so specifically when it was unclear at encoding which features would be needed in the future. Overall, these findings reveal a fundamental adaptive function of episodic memory, showing how its rich representational capacity enables flexible decision-making under uncertainty.
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Data availability
The data are available via GitHub at https://github.com/jonathanicholas/nm2025_emdm.
Code availability
The code is available via GitHub at https://github.com/jonathanicholas/nm2025_emdm.
References
Tulving, E. in Organization of Memory (eds Tulving, E. & Donaldson, W.) 381–403 (Academic Press, 1972).
Eichenbaum, H. The hippocampus and mechanisms of declarative memory. Behav. Brain Res. 103, 123–133 (1999).
Bartlett, F. C. Remembering: A Study in Experimental and Social Psychology (Cambridge Univ. Press, 1932).
Anderson, J. R. & Milson, R. Human memory: an adaptive perspective. Psychol. Rev. 96, 703–719 (1989).
Schacter, D. L., Guerin, S. A. & Jacques, P. L. S. Memory distortion: an adaptive perspective. Trends Cogn. Sci. 15, 467–474 (2011).
Shohamy, D. & Adcock, R. A. Dopamine and adaptive memory. Trends Cogn. Sci. 14, 464–472 (2010).
Lengyel, M. & Dayan, P. Hippocampal contributions to control: the third way. In Proc. Advances in Neural Information Processing Systems (eds Platt, J. C. et al.) 889–896 (Curran Associates, 2008).
Gershman, S. J. & Daw, N. D. Reinforcement learning and episodic memory in humans and animals: an integrative framework. Annu. Rev. Psycho. 68, 101–128 (2017).
Nagy, D. G., Orbán, G. & Wu, C. M. Adaptive compression as a unifying framework for episodic and semantic memory. Nat. Rev. Psychol. 4, 484–498 (2025).
Rescorla, R. A. & Wagner, A. R. in Classical Conditioning II: Current Research and Theory (eds Black, A. H. & Prokasy, W. F.) 64–99 (Appleton-Century-Crofts, 1972).
Shohamy, D. & Daw, N. D. in The Cognitive Neurosciences 5th edn (eds Gazzaniga, M. S. & Mangun, G. R.) 591–603 (Boston Review, 2014).
Knowlton, B. J., Mangels, J. A. & Squire, L. R. A neostriatal habit learning system in humans. Science 273, 1399–1402 (1996).
Schultz, W., Dayan, P. & Montague, P. R. A neural substrate of prediction and reward. Science 275, 1593–1599 (1997).
Bayer, H. M. & Glimcher, P. W. Midbrain dopamine neurons encode a quantitative reward prediction error signal. Neuron 47, 129–141 (2005).
Shohamy, D., Myers, C. E., Grossman, S., Sage, J. & Gluck, M. A. The role of dopamine in cognitive sequence learning: evidence from Parkinson’s disease. Behav. Brain Res. 156, 191–199 (2005).
Zaghloul, K. A. et al. Human substantia nigra neurons encode unexpected financial rewards. Science 323, 1496–1499 (2009).
Sutton, R. S. & Barto, A. G. Reinforcement Learning: An Introduction 2nd edn (MIT Press, 2018).
Wilson, R. C. & Niv, Y. Inferring relevance in a changing world. Front. Hum. Neurosci. 5, 189 (2012).
Leong, Y. C., Radulescu, A., Daniel, R., DeWoskin, V. & Niv, Y. Dynamic interaction between reinforcement learning and attention in multidimensional environments. Neuron 93, 451–463 (2017).
Niv, Y. et al. Reinforcement learning in multidimensional environments relies on attention mechanisms. J. Neurosci. 35, 8145–8157 (2015).
Miller, G. A. The magical number seven, plus or minus two: some limits on our capacity for processing information. Psychol. Rev. 63, 81–97 (1956).
Bornstein, A. M., Khaw, M. W., Shohamy, D. & Daw, N. D. Reminders of past choices bias decisions for reward in humans. Nat. Commun. 8, 15958 (2017).
Duncan, K., Semmler, A. & Shohamy, D. Modulating the use of multiple memory systems in value-based decisions with contextual novelty. J. Cogn. Neurosci. 31, 1455–1467 (2019).
Mason, A., Madan, C. R., Simonsen, N., Spetch, M. L. & Ludvig, E. A. Biased confabulation in risky choice. Cognition 229, 105245 (2022).
Nicholas, J., Daw, N. D. & Shohamy, D. Uncertainty alters the balance between incremental learning and episodic memory. eLife 11, e81679 (2022).
Montaser-Kouhsari, L., Nicholas, J., Gerraty, R. T. & Shohamy, D. Differentiating reinforcement learning and episodic memory in value-based decisions in Parkinson’s disease. J. Neurosci. 45, e0911242025 (2024).
Plonsky, O., Teodorescu, K. & Erev, I. Reliance on small samples, the wavy recency effect, and similarity-based learning. Psychol. Rev. 122, 621–647 (2015).
Daw, N. D. & Dayan, P. The algorithmic anatomy of model-based evaluation. Philos. Trans. R. Soc. B 369, 20130478 (2014).
Kool, W., Cushman, F. A. & Gershman, S. J. When does model-based control pay off? PLoS Comput. Biol. 12, e1005090 (2016).
Kahana, M. J. Foundations of Human Memory (Oxford Univ. Press, 2012).
Ratcliff, R. A theory of memory retrieval. Psychol. Rev. 85, 59–108 (1978).
Sederberg, P. B., Howard, M. W. & Kahana, M. J. A context-based theory of recency and contiguity in free recall. Psychol. Rev. 115, 893–912 (2008).
O’Reilly, R. C. & McClelland, J. L. Hippocampal conjunctive encoding, storage, and recall: avoiding a trade-off. Hippocampus 4, 661–682 (1994).
O'Reilly, R. C. & Rudy, J. W. Conjunctive representations in learning and memory: principles of cortical and hippocampal function. Psychol. Rev. 108, 311–345 (2001).
Rudy, J. W. & O’Reilly, R. C. Conjunctive representations, the hippocampus, and contextual fear conditioning. Cogn. Affect. Behav. Neurosci. 1, 66–82 (2001).
Lee, S. W., O’Doherty, J. P. & Shimojo, S. Neural computations mediating one-shot learning in the human brain. PLoS Biol. 13, e1002137 (2015).
Packard, M. G. & McGaugh, J. L. Inactivation of hippocampus or caudate nucleus with lidocaine differentially affects expression of place and response learning. Neurobiol. Learn. Mem. 65, 65–72 (1996).
Poldrack, R. A. & Packard, M. G. Competition among multiple memory systems: converging evidence from animal and human brain studies. Neuropsychologia 41, 245–251 (2003).
Stewart, N., Chater, N. & Brown, G. D. Decision by sampling. Cogn. Psychol. 53, 1–26 (2006).
Biele, G., Erev, I. & Ert, E. Learning, risk attitude and hot stoves in restless bandit problems. J. Math. Psychol. 53, 155–167 (2009).
Shadlen, M. N. & Shohamy, D. Decision making and sequential sampling from memory. Neuron 90, 927–939 (2016).
Wang, S., Feng, S. F. & Bornstein, A. M. Mixing memory and desire: how memory reactivation supports deliberative decision-making. WIREs Cogn. Sci. 13, e1581 (2022).
Hertwig, R. & Erev, I. The description–experience gap in risky choice. Trends Cogn. Sci. 13, 517–523 (2009).
Schlichting, M. L. & Preston, A. R. in The Hippocampus from Cells to Systems: Structure, Connectivity, and Functional Contributions to Memory and Flexible Cognition (eds Hannula, D. E. & Duff, M. C.) 405–437 (Springer, 2017).
Whittington, J. C. et al. The Tolman-Eichenbaum machine: unifying space and relational memory through generalization in the hippocampal formation. Cell 183, 1249–1263 (2020).
Biderman, N., Bakkour, A. & Shohamy, D. What are memories for? The hippocampus bridges past experience with future decisions. Trends Cogn. Sci. 24, 542–556 (2020).
Squire, L. R. & Zola, S. M. Structure and function of declarative and nondeclarative memory systems. Proc. Natl Acad. Sci. USA 93, 13515–13522 (1996).
Poldrack, R. A. et al. Interactive memory systems in the human brain. Nature 414, 546 (2001).
Daw, N. D., Niv, Y. & Dayan, P. Uncertainty-based competition between prefrontal and dorsolateral striatal systems for behavioral control. Nat. Neurosci. 8, 1704–1711 (2005).
Lee, S. W., Shimojo, S. & O’Doherty, J. P. Neural computations underlying arbitration between model-based and model-free learning. Neuron 81, 687–699 (2014).
Greve, A., Cooper, E., Tibon, R. & Henson, R. N. Knowledge is power: prior knowledge aids memory for both congruent and incongruent events, but in different ways. J. Exp. Psychol. Gen. 148, 325–341 (2019).
van Kesteren, M. T. R., Ruiter, D. J., Fernández, G. & Henson, R. N. How schema and novelty augment memory formation. Trends Neurosci. 35, 211–219 (2012).
Rouhani, N. & Niv, Y. Signed and unsigned reward prediction errors dynamically enhance learning and memory. eLife 10, e61077 (2021).
Jang, A. I., Nassar, M. R., Dillon, D. G. & Frank, M. J. Positive reward prediction errors during decision-making strengthen memory encoding. Nat. Hum. Behav. 3, 719–732 (2019).
Howard, M. W. & Kahana, M. J. A distributed representation of temporal context. J. Math. Psychol. 46, 269–299 (2002).
Polyn, S. M., Norman, K. A. & Kahana, M. J. A context maintenance and retrieval model of organizational processes in free recall. Psychol. Rev. 116, 129–156 (2009).
Kahana, M. J. Computational models of memory search. Annu. Rev. Psychol. 71, 107–138 (2020).
Bornstein, A. M. & Norman, K. A. Reinstated episodic context guides sampling-based decisions for reward. Nat. Neurosci. 20, 997–1003 (2017).
Aka, A. & Bhatia, S. What I like is what I remember: memory modulation and preferential choice. J. Exp. Psychol. Gen. 150, 2175–2184 (2021).
Michelmann, S., Staresina, B. P., Bowman, H. & Hanslmayr, S. Speed of time-compressed forward replay flexibly changes in human episodic memory. Nat. Hum. Behav. 3, 143–154 (2019).
Wimmer, G. E., Liu, Y., Vehar, N., Behrens, T. E. J. & Dolan, R. J. Episodic memory retrieval success is associated with rapid replay of episode content. Nat. Neurosci. 23, 1025–1033 (2020).
Liu, Y., Mattar, M. G., Behrens, T. E. J., Daw, N. D. & Dolan, R. J. Experience replay is associated with efficient nonlocal learning. Science 372, eabf1357 (2021).
McFadyen, J., Liu, Y. & Dolan, R. J. Differential replay of reward and punishment paths predicts approach and avoidance. Nat. Neurosci. 26, 627–637 (2023).
Wimmer, G. E., Liu, Y., McNamee, D. C. & Dolan, R. J. Distinct replay signatures for prospective decision-making and memory preservation. Proc. Natl Acad. Sci. USA 120, e2205211120 (2023).
Carmichael, L., Hogan, H. P. & Walter, A. A. An experimental study of the effect of language on the reproduction of visually perceived form. J. Exp. Psychol. 15, 73–86 (1932).
Nagy, D. G., Török, B. & Orbán, G. Semantic compression of episodic memories. Preprint at https://arxiv.org/abs/1806.07990 (2018).
Zhou, D. et al. A compressed code for memory discrimination. Preprint at bioRxiv https://doi.org/10.1101/2025.10.12.681901 (2025).
Kerrén, C., Reznik, D., Doeller, C. F. & Griffiths, B. J. Exploring the role of dimensionality transformation in episodic memory. Trends Cogn. Sci. 29, 614–626 (2025).
Nicholas, J., Daw, N. D. & Shohamy, D. Proactive and reactive construction of memory-based preferences. Nat. Commun. 16, 1618 (2025).
Hoffman, M. D. & Gelman, A. The No-U-Turn sampler: adaptively setting path lengths in Hamiltonian Monte Carlo. J. Mach. Learn. Res. 15, 1593–1623 (2014).
Bürkner, P.-C. Brms: an R package for Bayesian multilevel models using Stan. J. Stat. Softw. 80, 1–28 (2017).
Vehtari, A., Gelman, A. & Gabry, J. Practical Bayesian model evaluation using leave-one-out cross-validation and WAIC. Stat. Comput. 27, 1413–1432 (2017).
Sivula, T., Magnusson, M., Matamoros, A. A. & Vehtari, A. Uncertainty in Bayesian leave-one-out cross-validation based model comparison. Preprint at https://arxiv.org/abs/2008.10296 (2023).
Acknowledgements
We thank members of the Mattar Lab as well as K. Jensen, Q. Lu, N. Biderman and D. Shohamy for their helpful comments and feedback on the project. This work was supported by the National Science Foundation SBE Postdoctoral Research Fellowship under grant no. 2507527.
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J.N. and M.G.M. conceived the research and study design. J.N. conducted the data collection and analysis and drafted the paper. J.N. and M.G.M. reviewed and edited the paper.
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Nicholas, J., Mattar, M.G. Episodic memory facilitates flexible decision-making via access to detailed events. Nat Hum Behav (2026). https://doi.org/10.1038/s41562-025-02383-3
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DOI: https://doi.org/10.1038/s41562-025-02383-3


