# Value networks and hippocampal non-local representations

> **NIH NIH R01** · UNIVERSITY OF CALIFORNIA, SAN FRANCISCO · 2024 · $813,843

## Abstract

SUMMARY / ABSTRACT
 This proposal aims to reveal critical neural mechanisms for intelligent reward-driven learning and
decision-making. It is well established that animals, including humans, use internal models of the world to
guide their behavior. Model-based computations are especially vital in complex environments, where animals
often need to plan a sequence of choices leading to later rewards. Furthermore, after receiving a reward
animals update their reward predictions (“values”) – both for earlier choices they made, and for alternative
ways of reaching that reward. These adaptive behaviors rely on combining simulations (of potential paths) with
evaluations (of whether they are worthwhile).
 The hippocampus is believed to play a critical role in model-based decision-making, because it can
generate coherent “non-local” representations of distant places. These take at least two distinct forms. First, as
rats run through an environment hippocampal place cells generally represent current location, but during late
phases of the theta rhythm this place code can sweep forward to potential future locations. It was previously
found that these “theta sequences” can rapidly flicker between available choices, on alternating theta cycles –
highly suggestive of a role in evaluating options. Second, during immobility the hippocampus can produce
sharp-wave-ripple (SWR) events, that often encode highly-compressed sequences of places. These occur
much more often shortly after rats receive rewards – highly suggestive of a role in updating values. However,
whether hippocampal non-local activity patterns are actually used for these purposes is unknown, largely
because whether they access values is unknown. There is intriguing evidence that SWRs evoke activity
changes in the network of brain areas vital for value-guided decisions (including frontal cortex and ventral
striatum). But whether hippocampal non-local activity is actually associated with value retrieval (during theta
sequences) and/or value updating (during SWRs) is unknown.
 This proposal would rigorously assess the relationships between value-guided decision-making and
hippocampal non-local representations. We will employ advanced recording techniques and an innovative
foraging task, complemented by sophisticated decoding algorithms and precisely-timed manipulations. We will
test two specific hypotheses: that post-reward SWRs are used to update values of distant locations (Aim 1),
and that theta sequences are used for online, value-guided decisions (Aim 2). These Aims engage the full
combined expertise of our team of experimentalists and theoreticians, including large-scale recordings across
multiple regions, statistical methods to identify non-local representations, and reinforcement learning
algorithms to estimate decision variables from behavior. These studies have the potential to transform our
understanding of how our brains explore internal models to guide learning and decision-making.

## Key facts

- **NIH application ID:** 10998620
- **Project number:** 1R01MH136875-01A1
- **Recipient organization:** UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
- **Principal Investigator:** JOSHUA D BERKE
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $813,843
- **Award type:** 1
- **Project period:** 2024-07-01 → 2029-01-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10998620

## Citation

> US National Institutes of Health, RePORTER application 10998620, Value networks and hippocampal non-local representations (1R01MH136875-01A1). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/10998620. Licensed CC0.

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