# Developing a novel pupillometric assessment of autonomic function: Testing targeted individual differences in BMI, temperament & aerobic fitness

> **NIH NIH R21** · UNIVERSITY OF FLORIDA · 2020 · $190,625

## Abstract

Project Summary/Abstract
 Stress, both physical and psychological, is associated with compromised autonomic function,
altering either parasympathetic or sympathetic nervous system activity. Autonomic dysfunction is
implicated in physical (obesity/diabetes, etc.), psychological (anxiety/mood disorders, etc.) and
neurological (Parkinson's, etc. ) disorders, making it critical to develop reliable measures of system
function. A classic cardiovascular measure of parasympathetic function computes the variability in the
beat-to-beat electrocardiogram, but, recently, existing cardiovascular measures of sympathetic nervous
system activity have been called into question, prompting a search for new technologies. This
exploratory proposal investigates pupillometry as a novel measure of autonomic function, since pupil
diameter is under the control of two muscles - the sphincter and dilator - that are separately innervated
by parasympathetic or sympathetic nervous system activity, respectively. Recent data from our
laboratory suggest that different independent variables – the brightness and emotional arousal of
visually presented stimuli – can be used to independently index activity mediated by the
parasympathetic (sphincter) or sympathetic (dilator) nervous system. This proposal is the first to
suggest that pupil diameter may serve as a new, non-invasive, easy-to-measure index of autonomic
function and it's specific aims include: 1) assessing the test-retest reliability, agreeability, and validity of
autonomic estimates based on pupil diameter in separate bi-weekly assessments. 2) compare
autonomic estimates based on pupillary measures to classical cardiovascular estimates of autonomic
function, and 3) explore whether estimates of autonomic function defined by pupil diameter covary as
expected based on demonstrated individual differences in autonomic profiles based on body mass
index, core negative affect, and aerobic exercise. To the extent that pupil diameter serves as a reliable,
valid index of autonomic system function that is sensitive to individual differences, it promises an
exciting new avenue in diagnosing autonomic dysfunction in a variety of physical, psychological, and
neurological disorders, as well as in assessing effects of treatment on autonomic nervous system action.

## Key facts

- **NIH application ID:** 9937827
- **Project number:** 5R21MH120431-02
- **Recipient organization:** UNIVERSITY OF FLORIDA
- **Principal Investigator:** Margaret M Bradley
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $190,625
- **Award type:** 5
- **Project period:** 2019-06-01 → 2022-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9937827

## Citation

> US National Institutes of Health, RePORTER application 9937827, Developing a novel pupillometric assessment of autonomic function: Testing targeted individual differences in BMI, temperament & aerobic fitness (5R21MH120431-02). Retrieved via AI Analytics 2026-05-28 from https://api.ai-analytics.org/grant/nih/9937827. Licensed CC0.

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