Interaural delay modulates the prepulse inhibition of the startle reflex induced by binaural gap in humans

Ming Lei,Yu Ding

doi:10.1121/10.0005110

Abstract

This study used prepulse inhibition (PPI) of the acoustic startle reflex as a physiological measure to determine the sensitivity to a break in interaural correlation (BIC) in binaural gap detection and compared this physiological measure with the traditional behavioral measure. Results show that BIC could be used as a prepulse to induce PPI at different interaural delays. Furthermore, the PPIs induced by BIC at an interaural delay of 4 ms, but not 0, 2, or 8 ms, were correlated with the BIC delay threshold. These findings suggest that the BIC-induced PPI paradigm may serve as an objective measure of binaural gap detection.

Highlights

Listeners receive the sound waves directly coming from the sound sources, and numerous reflections of the sources from various directions in a noisy, reverberant environment
3.1 Delay thresholds for detecting break in interaural correlation (BIC) The results in task 1 showed that the longest interaural time difference (ITD) for the BIC detection varied in the range between 5.41 and 13.43 ms across ten participants [mean 1⁄4 8.87 ms, standard deviation (SD) 1⁄4 2.17 ms]
The results of this study showed that a BIC embedded in interaurally correlated noises could be used as a prepulse to induce PPI, and this PPI induced by BIC was modulated by interaural delay in linear fashion when the interaural delay increased from 0 to 8 ms

Summary

Introduction

Listeners receive the sound waves directly coming from the sound sources, and numerous reflections of the sources from various directions in a noisy, reverberant environment. The auditory system is highly sensitive to a binaurally uncorrelated noise fragment temporally embedded in the binaurally correlated noises, i.e., a change of interaural correlation from 1 to 0 and back to 1 [binaural gap or break in interaural correlation (BIC)] (Akeroyd and Summerfield, 1999; Huang et al, 2009; Huang et al, 2019; Kong et al, 2012; Li et al, 2013). Behavioral tests are used to determine the sensitivity to BIC. We determined whether the attenuation of acoustic startle amplitude induced by BIC might serve as an objective measure to assess sensitivity to changes in binaural correlation

Objectives

Methods

Results

Conclusion