| Poster | Poster Session 04 Program Schedule
02/15/2024
12:00 pm - 01:15 pm
Room: Majestic Complex (Posters 61-120)
Poster Session 04: Neuroimaging | Neurostimulation/Neuromodulation | Teleneuropsychology/Technology
Final Abstract #102
Transcutaneous Vagus Nerve Stimulation and Explicit Memory in Cognitively Healthy Older Adults
Destin Shortell, University of Florida, Gainesville, United States
Brain Ho, University of Florida, Gainesville, United States
Alexandra O'Neal, University of Florida, Gainesville, United States
Damon Lamb, University of Florida, Gainesville, United States
John Williamson, University of Florida, Gainesville, United States
Eric Porges, University of Florida, Gainesville, United States
Category: Neurostimulation/Neuromodulation
Keyword 1: aging (normal)
Objective:
The objective of the following research was to investigate the effect of non-invasive transcutaneous vagus nerve stimulation (tVNS) on delayed recall and sensitivity index in a sample of cognitively healthy older adults.
Participants and Methods:
The total sample included 13 individuals (46% women, 92.3% White, 61 to 83 years old, 16.6 average years of education) who completed four laboratory visits including an intake session to determine eligibility, two cognitive sessions with stimulation, and an MRI session with stimulation. The study employed a double-blind, crossover, randomized controlled trial design. Memory measures were calculated from the 15-item Rey Auditory Verbal Learning Test. Stimulation parameters were 20Hz with 100μs pulse width at 80% of discomfort threshold. Active tVNS occurred on the left tragus while sham stimulation was on the left earlobe. All analyses were conducted in R version 4.3.1. The analysis included linear mixed effects models with stimulation condition (tVNS or sham) and session order as within-subjects factors. All procedures were IRB approved.
Results:
Stimulation condition had a large, nonsignificant effect on delayed recall, such that tVNS improved delayed recall (β=0.86) compared to sham. The effect was not statistically significant likely due to the small sample size and variability (t(11.38)=1.12, p=.28, 95% CI (-6.06, 19.46)). Further, there was a moderate-to-large effect size (β=-0.64) for the condition-by-order interaction (t(11)=-0.78, p=.45, 95% CI=(-11.52, 5.39), though there was no main effect of session order (t(14.35)=-0.17, p=.87, 95% CI=(-4.83, 4.09), β=-0.047). Similar small to large, nonsignificant effects were observed for sensitivity index for stimulation condition (t(12.25)=0.74, p=.47, 95% CI=(-1.52, 3.13), β=0.60; moderate-to-large effect) and the condition-by-order interaction (t(12)=-0.44, p=.67, 95% CI=(-1.86, 1.23), β=-0.37; small-to-moderate effect). Session order was also negligible (t(14.25)=0.29, p=.78, 95% CI=(-0.69, 0.91), β=0.08).
Conclusions:
In this pilot dataset, effect size estimates suggest tVNS is a promising non-invasive intervention to improve memory in cognitively healthy older adults. Future studies should incorporate larger sample sizes with more diverse individuals and directly investigate mechanisms by which tVNS may affect memory.
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