# A multimodal study of delay activity contributions to short and long term memory

> **NIH NIH R56** · CITY COLLEGE OF NEW YORK · 2020 · $392,500

## Abstract

PROJECT SUMMARY/ABSTRACT
Delay activity is neural activity that occurs within a few seconds between the encoding of relevant stimuli and
memory retrieval. Delay activity is a key component of working memory, a cognitive process that allows us to
hold information online and manipulate it to realize immediate and future goals. While delay activity has been
extensively studied in animals and humans using a variety of neuroscientific recording methods and different
levels of data analysis, there remain several gaps in understanding the mechanisms by which delay activity
contributes to both short- and long-term memory. Recent studies question the long-standing theoretical
framework that elevated and sustained delay activity is the basis for memory maintenance. Findings from these
studies suggest that delay activity is often transient or burst-like, and that unattended stimuli may even be
maintained in activity-silent hidden states. These new findings motivate the experiments outlined here to
understand how observable delay activity contributes to memory formation. This proposal will combine high
temporal resolution electroencephalographic and high spatial resolution functional MRI methods to test in human
participants the overarching hypothesis that early and late components of delay activity contribute to memory
formation. The first aim will study the effects of varying the delay interval duration and content on delay period
activity and memory using the techniques of electroencephalography (EEG) and functional magnetic resonance
imaging (fMRI). The hypothesis is there will be a temporal correspondence between EEG delay period
synchronization and BOLD-fMRI amplitude, with a positive relationship of both to subsequent memory. The
second aim will study the effects of delay period EEG synchronization/desynchronization and hippocampal-cortical fMRI connectivity on memory. The hypothesis is that early synchronization and later desynchronization
in delay periods reflects hippocampal-cortical binding and cortico-cortical reactivation preceding memory
retrieval. The third aim will study the effects of EEG delay activity and subsequent sleep spindles on memory.
The hypothesis is that more delay activity will elicit long-term memory consolidation processes during a post-learning sleep period. Together the completion of these three aims will contribute to a basic understanding of
the role of delay activity in memory. The outcomes will provide valuable insight into why certain mental health
and neurological disorders, which include aberrant delay activity, lead to complex patterns of both short- and
long-term memory impairments.

## Key facts

- **NIH application ID:** 9893025
- **Project number:** 5R56MH116007-02
- **Recipient organization:** CITY COLLEGE OF NEW YORK
- **Principal Investigator:** Timothy Ellmore
- **Activity code:** R56 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $392,500
- **Award type:** 5
- **Project period:** 2019-04-01 → 2023-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9893025

## Citation

> US National Institutes of Health, RePORTER application 9893025, A multimodal study of delay activity contributions to short and long term memory (5R56MH116007-02). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/9893025. Licensed CC0.

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