# Temporal Synthesis of Vestibular and Extra-Vestibular Sensory Signals

> **NIH NIH R01** · MASSACHUSETTS EYE AND EAR INFIRMARY · 2020 · $528,669

## Abstract

Multiple sensory cues are generated by discrete events and while they do not reach the cerebrum
simultaneously, the brain can synthesize them if they are interpreted as corresponding to a single event. This
is critical because the central representation of an event or action is improved if two or more relevant cues are
integrated but conversely is degraded if unrelated inputs are mistakenly synthesized. Little research has
focused on temporal binding of vestibular and non-vestibular cues even though the vestibular system operates
in an inherently multimodal environment, and virtually nothing is known about abnormalities in temporal binding
that occur with peripheral or central vestibular disorders. Temporal binding is often quantified with two values
derived from psychophysical tests, the point of subjective simultaneity (PSS) and the temporal binding window
(TBW). We will use these perceptual measures to test a series of hypotheses about the physiology and
pathophysiology of vestibular temporal binding. Two sets of specific aims will be investigated: Aim 1 will
investigate the mechanisms used by the brain to bind vestibular and non-vestibular signals in time. Aim 1A
examines how the precision of the vestibular signal affects its binding with non-vestibular cues. Precision
(1/variability) of the spatial and temporal characteristics of vestibular afferents and their relationship to temporal
binding will be studied in normal subjects, and we predict that the two precision measures will be correlated
with each other and with the TBW. We will also manipulate vestibular precision using patients with combined
vestibular (VI) and cochlear (CI) implants in the same ear and predict that additional noise will widen the TBW
and increase the PSS. Aim 1B uses the prosthetic signals that are available in the VI-CI patients to examine
how adaptation driven by habitual exposure to timing cues affects temporal binding. Since the brain is naïve to
these stimulus pairs and the patients have longstanding absence of cochlear and vestibular function in both
ears, we can study how the brain binds signals in time when it has no prior exposure to the cues, and predict
that the PSS will reflect the relative time for the signals to reach the cerebrum, the TBW will be wide, and both
will be abnormally amenable to adaptation. Aim 2 investigates how temporal binding contributes to the
pathophysiology of peripheral and central vestibular disorders. Aim 2A examines the effects of acute loss of
peripheral vestibular function and the subsequent process of compensation on temporal binding. We predict
that both passive and active processes will contribute to recalibration of the PSS and TBW, that patient
outcome will correlate with the changes in these values, and that adaptation of the PSS and TBW will improve
clinical outcome. Aim 2B examines how temporal binding contributes to central vestibular dysfunction,
focusing on motion sickness and migraine. We predict that subjects with...

## Key facts

- **NIH application ID:** 9823872
- **Project number:** 5R01DC017425-02
- **Recipient organization:** MASSACHUSETTS EYE AND EAR INFIRMARY
- **Principal Investigator:** TIMOTHY E HULLAR
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $528,669
- **Award type:** 5
- **Project period:** 2019-01-01 → 2023-12-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9823872

## Citation

> US National Institutes of Health, RePORTER application 9823872, Temporal Synthesis of Vestibular and Extra-Vestibular Sensory Signals (5R01DC017425-02). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/9823872. Licensed CC0.

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