# Convergent Natural and Prosthetic Vestibular Signals

> **NIH NIH R21** · UNIVERSITY OF ROCHESTER · 2021 · $165,182

## Abstract

Implantable vestibular prosthetic devices, based on cochlear implants, are an emerging
technology currently in limited clinical trials. These devices have significant technical
constraints and may have limited ability to restore reflexive eye movements with head motion,
and appear promising for improving function in some patients with bilateral vestibular deficits.
To date, all available devices only stimulate semicircular canal afferents to restore sensitivity to
angular acceleration. The other half of the vestibular system, that responding to linear
acceleration, is not addressed by these prostheses. Our hypothesis is that restoration of
semicircular canal function can improve a patients’ sense of balance by working with residual
otolith function. If true, our findings may help select the candidates for vestibular implantation
who would be most likely to benefit from this technology. Our methodology is to examine eye
movements and perform single unit recordings from macaques with vestibular implants during
combined linear acceleration and prosthetic semicircular canal stimulation. Our project has two
specific aims. In the first, we will examine if prosthetic canal stimulation, like natural canal
stimulation, can enable discrimination between linear acceleration from gravity from acceleration
due to translation. The ability to discriminate tilt from translation is a fundamental role of the
semicircular canal system and critical to spatial orientation. This first aim will use the differences
in eye movements elicited during tilt and translation to discern whether prosthetic canal signals
can facilitate discrimination of reorientation due to gravity from translation. In the second aim,
we will record single unit vestibular nucleus neuronal activity to compare the interactions of
prosthetic semicircular canal signals with natural otolith signals to interactions of natural
semicircular canal and otolith signals. These experiments will be the first looking at how
prosthetic vestibular signals and natural signals interact in the brain. These experiments should
provide insight into how the brain process signals from currently used vestibular prostheses and
may lead to improvements in approaches to treatment of vestibular problems.

## Key facts

- **NIH application ID:** 10131805
- **Project number:** 5R21DC018083-02
- **Recipient organization:** UNIVERSITY OF ROCHESTER
- **Principal Investigator:** Shawn D. Newlands
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $165,182
- **Award type:** 5
- **Project period:** 2020-04-01 → 2023-09-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10131805

## Citation

> US National Institutes of Health, RePORTER application 10131805, Convergent Natural and Prosthetic Vestibular Signals (5R21DC018083-02). Retrieved via AI Analytics 2026-06-01 from https://api.ai-analytics.org/grant/nih/10131805. Licensed CC0.

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