Auditory streaming and bistability paradigm extended to a dynamic environment

Áine Byrne,James Rankin,John Rinzel

doi:10.1016/j.heares.2019.107807

Áine Byrne, James Rankin + Show 1 more

Open Access

https://doi.org/10.1016/j.heares.2019.107807

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Journal: Hearing Research	Publication Date: Oct 5, 2019
Citations: 6	License type: cc-by

Affiliation: New York University, University of Exeter

Abstract

We explore stream segregation with temporally modulated acoustic features using behavioral experiments and modelling. The auditory streaming paradigm in which alternating high- A and low-frequency tones B appear in a repeating ABA-pattern, has been shown to be perceptually bistable for extended presentations (order of minutes). For a fixed, repeating stimulus, perception spontaneously changes (switches) at random times, every 2–15 s, between an integrated interpretation with a galloping rhythm and segregated streams. Streaming in a natural auditory environment requires segregation of auditory objects with features that evolve over time. With the relatively idealized ABA-triplet paradigm, we explore perceptual switching in a non-static environment by considering slowly and periodically varying stimulus features. Our previously published model captures the dynamics of auditory bistability and predicts here how perceptual switches are entrained, tightly locked to the rising and falling phase of modulation. In psychoacoustic experiments we find that entrainment depends on both the period of modulation and the intrinsic switch characteristics of individual listeners. The extended auditory streaming paradigm with slowly modulated stimulus features presented here will be of significant interest for future imaging and neurophysiology experiments by reducing the need for subjective perceptual reports of ongoing perception.

Highlights

In a dynamic auditory world the brain must resolve ambiguity between sounds and isolate objects of interest
For modulation periods near 2Teq this pattern of two switches per modulation period can persist. Our modelling confirmed such expectations and led to the following modelling predictions: 1) alternations entrain to the stimulus modulation with two switches per modulation cycle, 2) switches into segregated occur on the difference in tone frequency (DF) upswing, with most switches occurring before the maximal DF values and 3) entrainment is stronger when the DF modulation period is near double the mean percept duration at equidominance (Tmod 1⁄4 2Teq)
Periodic modulation of DF was introduced noting that the integrated stream (Int) percept is more likely at low DF and the Seg percept is more likely at large DF

Summary

Introduction

In a dynamic auditory world the brain must resolve ambiguity between sounds and isolate objects of interest. A valued paradigm for investigating such processes is auditory streaming, in which alternating high- A and lowfrequency tones B appear in a repeating ABA-pattern (van Noorden, 1975). The first perceptual switch, typically from integrated to segregated, is followed by persistent alternations every 2e15 s between the two interpretations (auditory bistability) (Pressnitzer and Hupe, 2006; Kondo and Kashino, 2009; Winkler et al, 2012; Rankin et al, 2015; Denham et al, 2018). A striking aspect of auditory bistability (and perceptual bistability more generally (Rodríguez-Martínez and Castillo-Parra, 2018)) is that a fixed repeating stimulus gives rise to two or more perceptual interpretations. Streaming in a natural auditory environment requires segregation of auditory objects with features that evolve over time

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