The hippocampus as a generative model

Clinical Snapshot

Key Findings

• Effect Size: Not applicable — no quantitative effect sizes reported

• Primary Outcome: Theoretical proposition that the hippocampus functions as a generative model encoding latent, unobserved causes of sensory data by virtue of its position within the deep cortical hierarchy, enabling memory, future simulation, and internally generated learning signals

• Nnt Or Sensitivity: Not applicable — theoretical review; no diagnostic, therapeutic, or prognostic metrics reported. The framework predicts that perturbations to hippocampal generative model function may explain core symptoms of psychosis, but this is not quantified.

• Confidence Interval: Not applicable — no statistical analyses performed

Clinical Application

The framework itself is not a clinical intervention and requires no immediate implementation. Its clinical utility depends on future empirical validation through experimental paradigms, neuroimaging studies, and ultimately clinical trials targeting hippocampal generative model dysfunction. Feasibility of translation is medium-to-long term. In the Australian context, this theoretical framework has potential relevance to RANZCP-guided management of psychosis and schizophrenia spectrum disorders, where hippocampal volume loss and memory dysfunction are recognised features. The framework may inform future biomarker development relevant to TGA-approved neuroimaging or cognitive assessment tools. No current PBS-listed interventions are directly implicated. RACGP guidelines on cognitive assessment in older adults and early psychosis detection may eventually benefit from mechanistic insights derived from this framework. Australian research groups within the NHMRC-funded neuroscience ecosystem — including those at the Florey Institute and QIMR Berghofer — may find this framework relevant to ongoing hippocampal research programs. Broadly applicable as a theoretical framework for understanding hippocampal contributions to memory, cognition, and neuropsychiatric disorders in humans. Most directly relevant to clinicians and researchers working with patients experiencing psychosis, schizophrenia spectrum disorders, or conditions involving hippocampal dysfunction. Indirect relevance to dementia, epilepsy, and post-traumatic stress disorder where hippocampal pathology is prominent.

Abstract

A generative model can be defined as a model of the latent causes of sensory input that can be used to generate new data samples. By examining empirical evidence and computational theory, we propose that the hippocampus can be characterized as a generative model. The hippocampus is a brain region important for memory. Recordings of neural activity from the hippocampus have led to the view that the hippocampus represents a cognitive map by abstracting a low-dimensional representation of the external world. We extend this view to suggest the hippocampus represents the latent, unobserved causes of sensory data by virtue of the position of the hippocampus within the deep cortical hierarchy. These representations of unobserved latent causes endow the hippocampus with capacity to generate new data samples that allow exploration of future hypotheticals and provide an internally generated training signal back to the generative model. We explore how perturbations to the hippocampal generative model may explain core symptoms of neuropsychiatric disorders such as those observed in psychosis. Together, this perspective provides a unified account of hippocampal function that explains how computations performed by the hippocampus support higher-order cognition and adaptive behaviour. This article is part of the theme issue 'The role of hippocampal predictions in cognition: bridging perception and memory'.

References

1. 1.Nalluru, S., Glitz, L., Przygodda, X., Mancini, V., & Barron, H. C. (2026). The hippocampus as a generative model. Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences. https://doi.org/10.1098/rstb.2025.0247