# The effects of noradrenergic activity on age-related distractibility

> **NIH NIH F32** · UNIVERSITY OF SOUTHERN CALIFORNIA · 2022 · $67,174

## Abstract

Post mortem and neuroimaging data suggest an intact locus coeruleus helps to maintain cognitive performance
in older adults. However, the basic mechanisms of this relationship are still unknown. The locus coeruleus is the
source of most of the brain's noradrenaline but it is not yet clear how age-related decline in the locus coeruleus
affects noradrenergic activity, and in turn, how these changes in noradrenergic activity modulate cognitive
behavior. For instance, it is unknown whether age-related deficiencies in neuromodulation and processing result
from decreased or increased locus coeruleus activity. Our long-term objectives are to determine the role of
noradrenergic activity in modulating cognitive impairments and to identify means of preserving stable autonomic
function to prevent or delay the progression of neurodegenerative diseases. The specific research goals of this
proposal are to identify the mechanisms by which noradrenergic activity modulates distractibility by salient but
irrelevant distractors in older and young adults. Both specific aims will utilize resting state recordings and an
oculomotor search task that measures attentional inhibition of eye movements to determine whether tonic
noradrenergic discharge directly modulates inhibitory mechanisms of attentional control. In Aim 1, we will
investigate whether elevating tonic noradrenergic activity in older and young adults using threat of unpredictable
shock induces arousal by pupillometric and electrophysiological measures. Furthermore, we will examine
whether these changes will influence attentional control by modulating the magnitude of attentional inhibition of
eye movements and phasic noradrenergic responses. We predict that older adults' distractibility will be less
modulated by threat of shock than that of younger adults given our hypothesis that older adults already sustain
higher levels of tonic noradrenergic release and hyperactivity. In Aim 2, we will investigate whether reducing
tonic noradrenergic activity following slow-paced breathing and meditative practices improves attentional focus
in older adults and young adults with high basal sympathetic activity. The goal of this aim is to determine the
functional benefits of managing noradrenergic activity for attentional control as well as for measures of general
arousal and phasic noradrenergic discharge. We predict that the benefits of the intervention in Aim 2 will be
greater in older adults than that in young adults. The overall findings from this proposal will address a critical gap
in knowledge connecting the mechanisms of neuromodulation on age-related declines to behavior, with
theoretical implications in neuroprotection and preservation during aging. In addition, the training goals and
objectives builds on the applicant's research expertise in psychophysiological research and fMRI with research
expertise in the field of aging, training in EEG methodologies and analyses tools that are used in the field, and
the pr...

## Key facts

- **NIH application ID:** 10536457
- **Project number:** 1F32AG076288-01A1
- **Recipient organization:** UNIVERSITY OF SOUTHERN CALIFORNIA
- **Principal Investigator:** Andy Jeesu Kim
- **Activity code:** F32 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $67,174
- **Award type:** 1
- **Project period:** 2022-12-01 → 2025-02-28

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10536457

## Citation

> US National Institutes of Health, RePORTER application 10536457, The effects of noradrenergic activity on age-related distractibility (1F32AG076288-01A1). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10536457. Licensed CC0.

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