# Representation of spatiotemporal information in human episodic memory and navigation

> **NIH NIH R01** · UNIVERSITY OF ARIZONA · 2020 · $354,817

## Abstract

The goal of this project is to determine the neural basis of the spatial and temporal
components that comprise human episodic memory and navigation. Damage to the
human hippocampus results in significant impairments to both episodic memory and
navigation yet the commonalities behaviorally and neurally remain unclear. We
hypothesize that spatial and temporal contextual representations, which in turn include
temporal order and interval, underlie episodic memory and navigation in both partially
overlapping and unique manners. To understand how the hippocampus codes spatial
and temporal context, Aim 1 focuses on employing high-resolution hippocampal
functional magnetic resonance imaging (fMRI) and intracranial encephalography (iEEG)
to better understand the specific contributions of the microcircuitry of the human
hippocampus. Building on experiments and a model we have developed in the past
funding period, we hypothesize that hippocampal subfields CA3/DG play a role in
differentiation of spatial vs. temporal context while CA1 plays a role in integrating
commonalities across these two different forms of context. High-resolution hippocampal
fMRI experiments directly test these ideas by employing a combination of experimental
designs to tease apart spatial and temporal processing coupled with multivariate pattern
analyses (MVPA) to map hippocampal distributed codes for these behavioral
components. Hippocampal iEEG experiments focus on understanding how low-
frequencies oscillations code both spatial distance and temporal contexts, particularly
temporal intervals, which we hypothesize relates primarily to differences in the
frequencies of oscillations. Aim 2 provides a more “macro” perspective on human
episodic memory and navigation, with a focus on the unique cortical-hippocampal and
cortical-cortical networks that comprise spatial vs. temporal (order and interval)
contextual processing. Building on experiments and a model we have developed over
the past funding period, we will employ both whole brain fMRI and multilobular iEEG
recordings in patients undergoing seizure monitoring to determine the unique cortical
contributions to spatial vs. temporal context. We hypothesize that unique configurations
of networks and frequencies of interactions, such as prefrontal-hippocampal interactions
for temporal context and parietal-retrosplenial-hippocampal interactions for spatial
context, are critical to these representations. Proposed experiments directly test these
ideas by again employing both episodic memory and navigation related paradigms. The
expected outcomes from this proposal are a better understanding, at both the micro and
macro level scale, of how spatial vs. temporal context contribute to human episodic
memory and navigation. Specifically, by better understanding the contributions of the
hippocampal circuitry to episodic memory and navigation, we can better understand
how diseases like stroke and ischemia impact function there. In addition, by deli...

## Key facts

- **NIH application ID:** 9919002
- **Project number:** 5R01NS076856-08
- **Recipient organization:** UNIVERSITY OF ARIZONA
- **Principal Investigator:** ARNE D EKSTROM
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $354,817
- **Award type:** 5
- **Project period:** 2012-07-01 → 2023-04-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9919002

## Citation

> US National Institutes of Health, RePORTER application 9919002, Representation of spatiotemporal information in human episodic memory and navigation (5R01NS076856-08). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/9919002. Licensed CC0.

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