Optimizing Noisy Galvanic Vestibular Stimulation Frequency Range for Enhancing Vestibular Perception and Manual Control Performance

Assessments of Performance in Healthy Control Subjects

This randomized crossover interventional study evaluated the effects of different frequency ranges of noisy galvanic vestibular stimulation (nGVS) on vestibular perception, perceptual motion tracking, and manual control performance in healthy adults. Each participant completed three experimental conditions in randomized order: no stimulation (control), low-frequency nGVS, and high-frequency nGVS. Vestibular perceptual thresholds, perceptual tracking, and manual control performance were assessed during each condition to determine whether stimulation frequency influenced sensorimotor function.

Study Overview

• Status: Completed
• Conditions: Vestibular Function Tests; Sensorimotor Performance
• Intervention / Treatment: Device: Low-frequency noisy galvanic vestibular stimulation (nGVS); Device: High-frequency noisy galvanic vestibular stimulation (nGVS)

Detailed Description

The purpose of this study was to investigate whether the frequency content of noisy galvanic vestibular stimulation influences vestibular perceptual sensitivity, tracking accuracy, and manual control performance. Healthy adult participants completed a randomized crossover protocol in which they received no stimulation, low-frequency nGVS, and high-frequency nGVS during separate experimental conditions within a single study session. Outcome measures included vestibular perceptual thresholds, tracking error rate, and measures of manual control performance. The results were intended to improve understanding of vestibular neuromodulation and inform optimization of nGVS parameters for future aerospace and clinical applications.

• Study Type: Interventional
• Enrollment (Actual): 18
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Texas
    • Houston, Texas, United States, 77058
      • Nasa Jsc B21

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Subjects were required to pass a physical exam adminisitrated by NASA JSC Clinic.

Exclusion Criteria:

• No history of neurologic, vestibular, or autonomic disease.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Single

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
No Intervention: Control - No noisy galvanic vestibular stimulation; Participants completed testing without noisy galvanic vestibular stimulation.
Experimental: Low-frequency noisy galvanic vestibular stimulation; Participants received low-frequency noisy galvanic vestibular stimulation during testing. Low frequency was 0-2 Hz.	Device: Low-frequency noisy galvanic vestibular stimulation (nGVS); Participants received low-frequency noisy galvanic vestibular stimulation through electrodes placed over the bilateral mastoid processes during experimental testing. Stimulation parameters were consistent with the approved study protocol. Frequency was 0-2Hz white noise, 300uA amplitude.
Experimental: High-frequency noisy galvanic vestibular stimulation; Participants received high-frequency noisy galvanic vestibular stimulation during testing. High-frequency was 10-30 Hz.	Device: High-frequency noisy galvanic vestibular stimulation (nGVS); Participants received high-frequency noisy galvanic vestibular stimulation through electrodes placed over the bilateral mastoid processes during experimental testing. Stimulation parameters were consistent with the approved study protocol. Frequency was 10-30Hz white noise, 300uA amplitude.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Vestibular Direction Recognition Threshold	Vestibular perceptual sensitivity was assessed using roll-tilt and interaural translation direction recognition tasks performed on a six-degree-of-freedom motion platform. Direction recognition thresholds were estimated from participant responses using an adaptive three-down, one-up staircase procedure and cumulative Gaussian psychometric curve fitting. Lower threshold values indicate greater vestibular sensitivity and improved perception of self-motion.	Day 1 (single study visit): Participants completed outcome assessments during each randomized intervention condition (No nGVS, Low-Frequency nGVS, and High-Frequency nGVS). Each assessment required approximately 5 minutes to complete.
Perceptual Motion Tracking Accuracy	Perceptual motion tracking performance was evaluated during continuous pseudorandom roll motion. Participants used a joystick to continuously indicate their perceived direction and magnitude of platform motion. Performance was quantified using the root mean square error (RMSE) between joystick responses and the programmed motion stimulus, with lower RMSE values indicating more accurate perception and tracking of self-motion.	Day 1 (single study visit): Participants completed outcome assessments during each randomized intervention condition (No nGVS, Low-Frequency nGVS, and High-Frequency nGVS). Each assessment required approximately 5 minutes to complete.
Manual Control Nulling Accuracy	Manual control performance was evaluated during continuous pseudorandom roll motion while participants used a joystick to actively minimize platform motion by generating corrective control inputs. Performance was quantified using the root mean square error (RMSE) between the platform tilt angle and the upright position over time. Lower RMSE values indicate more effective manual control and disturbance rejection.	Day 1 (single study visit): Participants completed outcome assessments during each randomized intervention condition (No nGVS, Low-Frequency nGVS, and High-Frequency nGVS). Each assessment required approximately 5 minutes to complete.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Roll-Tilt Vestibular Direction Recognition Threshold	Vestibular perceptual threshold for roll-tilt motion was measured using a computerized three-down, one-up adaptive staircase procedure during a 1 Hz sinusoidal motion stimulus. Thresholds were estimated by fitting a cumulative Gaussian psychometric function to participants' left/right direction recognition responses. Lower threshold values indicate greater vestibular sensitivity.	Day 1 (single study visit): Participants completed outcome assessments during each randomized intervention condition (No nGVS, Low-Frequency nGVS, and High-Frequency nGVS). Each assessment required approximately 5 minutes to complete.
Interaural Translation Vestibular Direction Recognition Threshold	Vestibular perceptual threshold for interaural translation motion was measured using a computerized three-down, one-up adaptive staircase procedure during a 1 Hz sinusoidal motion stimulus. Thresholds were estimated by fitting a cumulative Gaussian psychometric function to participants' left/right direction recognition responses. Lower threshold values indicate greater vestibular sensitivity.	Day 1 (single study visit): Participants completed outcome assessments during each randomized intervention condition (No nGVS, Low-Frequency nGVS, and High-Frequency nGVS). Each assessment required approximately 5 minutes to complete.
Vestibular Direction Recognition Bias	Response bias during the vestibular direction recognition task was estimated from the mean of the cumulative Gaussian psychometric function. Bias represents the stimulus magnitude at which participants were equally likely to perceive motion in either direction, providing a measure of systematic perceptual offset.	Day 1 (single study visit): Participants completed outcome assessments during each randomized intervention condition (No nGVS, Low-Frequency nGVS, and High-Frequency nGVS). Each assessment required approximately 5 minutes to complete.
Perceptual Motion Tracking Variability	Variability of perceptual motion tracking performance during continuous pseudorandom roll motion. Tracking variability was quantified using statistical measures including standard deviation and variance of tracking performance, providing an assessment of the consistency and precision of participant responses.	Day 1 (single study visit): Participants completed outcome assessments during each randomized intervention condition (No nGVS, Low-Frequency nGVS, and High-Frequency nGVS). Each assessment required approximately 5 minutes to complete.
Manual Control Nulling Variability	Variability of manual control performance during the nulling task was quantified using standard deviation, variance, and mean absolute deviation of chair tilt relative to the upright position. These measures assessed the consistency and precision of participants' ability to minimize platform motion.	Day 1 (single study visit): Participants completed outcome assessments during each randomized intervention condition (No nGVS, Low-Frequency nGVS, and High-Frequency nGVS). Each assessment required approximately 5 minutes to complete.

Collaborators and Investigators

• Sponsor: National Aeronautics and Space Administration (NASA)
• Investigators: Principal Investigator: Scott J Wood, PhD, National Aeronautics and Space Administration (NASA)

Study record dates

Study Major Dates

• Study Start (Actual): February 19, 2024
• Primary Completion (Actual): March 18, 2024
• Study Completion (Actual): March 18, 2024

Study Registration Dates

• First Submitted: July 15, 2026
• First Submitted That Met QC Criteria: July 22, 2026
• First Posted (Actual): July 28, 2026

Study Record Updates

• Last Update Posted (Actual): July 28, 2026
• Last Update Submitted That Met QC Criteria: July 22, 2026
• Last Verified: July 1, 2026

More Information

Terms related to this study

• Other Study ID Numbers: eIRB Study 0530

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: De-identified individual participant data underlying the results reported in the publication, including vestibular threshold measurements, perceptual motion tracking data, manual control performance data, and associated analysis code, will be made available upon reasonable request to the corresponding author. Additional study documents, including the study protocol, statistical analysis plan, and data dictionary, will also be available to support reproducibility. Data sharing will be subject to applicable institutional policies, IRB requirements, and any NASA data-sharing requirements in effect at the time of the request.
• IPD Sharing Time Frame: For at least five years following publication.
• IPD Sharing Access Criteria: Data can be requested through the NASA Life Sciences Portal (https://www.nasa.gov/hrp/nlsp/).
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP; ANALYTIC_CODE

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No