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Auditory tracking and scene analysis - perceptual timescales and neural correlates

thesis
posted on 21.04.2022, 18:54 by Ravinderjit SinghRavinderjit Singh

Temporal processing and temporal coherence processing are fundamental components of auditory processing and the focus of this thesis. Cortical temporal processing in particular is understudied in humans. This dissertation makes three contributions that help characterize auditory temporal processing, and its relationship to auditory perception in humans. Experiment 1 develops a novel systems identification approach utilizing modified maximum length sequences (m-seq) to robustly measure cortical temporal processing noninvasively. Using this technique, it is found that cortex's ability to track dynamic spatial auditory cues can explain the ability to utilize dynamic binaural information to do a spatial unmasking task. This result combined with behavioral data that shows FM tracking extends out to similar rates as spatial tracking demonstrates how auditory tracking broadly is constrained by the temporal properties of cortex. Experiment 2 develops a novel measure of temporal processing, called the modulation temporal response function (mod-TRF), which can separate the underlying sources contributing to modulation processing along the auditory system from short, middle, and late latency regions. The mod-TRF has a robust SNR at the individual level giving it the potential to become an ubiquitous tool to assess temporal processing and auditory activity generally across individuals. The utility of the mod-TRF is demonstrated by evaluating how attention affects different sources along the auditory pathway. Other studies utilizing the mod-TRF could explore how temporal processing in early and late areas of the auditory system changes with aging, hearing loss, musicianship, and neuropsychiatric disorders. Experiment 3 establishes a novel physiological measure of across channel temporal coherence processing to measure auditory binding ability across individuals. It  is demonstrated how this novel temporal coherence measure can explain performance on a behavioral temporal coherence detection task, speech-in-noise task, and comodulation masking release. Lastly, it is explored how social and communicative features in individuals, measured via the Autism Quotient, align with differences in auditory ability at various tasks. 

Funding

Interdisciplinary Training in Auditory Neuroscience

National Institute on Deafness and Other Communication Disorders

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Individualized assays of supra-threshold hearing deficits

National Institute on Deafness and Other Communication Disorders

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History

Degree Type

Doctor of Philosophy

Department

Biomedical Engineering

Campus location

West Lafayette

Advisor/Supervisor/Committee Chair

Hari Bharadwaj

Additional Committee Member 2

Edward Bartlett

Additional Committee Member 3

Gregory Francis

Additional Committee Member 4

Michael Heinz