Nonlinear dynamics in auditory cortical activity reveal the neural basis of perceptual warping in speech categorization

Authors

Jared A. Carter, Institute for Intelligent Systems, University of Memphis, Memphis, Tennessee 38152, USA.Follow
Eugene H. Buder, School of Communication Sciences and Disorders, University of Memphis, Memphis, Tennessee 38152, USA.Follow
Gavin M. Bidelman, Department of Speech, Language and Hearing Sciences, Indiana University, , Bloomington, Indiana 47408, USA jcrter29@memphis.edu, ehbuder@memphis.edu, gbidel@indiana.edu.Follow

Abstract

Surrounding context influences speech listening, resulting in dynamic shifts to category percepts. To examine its neural basis, event-related potentials (ERPs) were recorded during vowel identification with continua presented in random, forward, and backward orders to induce perceptual warping. Behaviorally, sequential order shifted individual listeners' categorical boundary, versus random delivery, revealing perceptual warping (biasing) of the heard phonetic category dependent on recent stimulus history. ERPs revealed later (∼300 ms) activity localized to superior temporal and middle/inferior frontal gyri that predicted listeners' hysteresis/enhanced contrast magnitudes. Findings demonstrate that interactions between frontotemporal brain regions govern top-down, stimulus history effects on speech categorization.

Publication Title

JASA express letters

Recommended Citation

Carter, J. A., Buder, E. H., & Bidelman, G. M. (2022). Nonlinear dynamics in auditory cortical activity reveal the neural basis of perceptual warping in speech categorization. JASA express letters, 2 (4), 045201. https://doi.org/10.1121/10.0009896